- Email: [email protected]
Quality of anthelminthic medicines available in Jimma Ethiopia
Acta Tropica 177 (2018) 157–163
Contents lists available at ScienceDirect
Acta Tropica journal homepage: www.elsevier.com/locate/actatropica
Quality of anthelminthic medicines available in Jimma Ethiopia a,b
b
a
a
MARK a
Sileshi Belew , Sultan Suleman , Evelien Wynendaele , Matthias D’Hondt , Anne Kosgei , ⁎ Luc Duchateauc, Bart De Spiegeleera, a b c
Drug Quality and Registration (DruQuaR) Group, Faculty of Pharmaceutical Sciences, Ghent University, Ottergemsesteenweg 460, B-9000 Ghent, Belgium School of Pharmacy, Jimma University, PO Box 378, Jimma, Ethiopia Department of Biometrics, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, B-9820 Merelbeke, Belgium
A R T I C L E I N F O
A B S T R A C T
Keywords: Anthelminthics Ethiopia Pharmaceutical quality Survey
Soil-transmitted helminthiasis and schistosomiasis are major public health problems in Ethiopia. Mass deworming of at-risk population using a single dose administration of 400 mg albendazole (ABZ) or 500 mg mebendazole (MBZ) for treatment of common intestinal worms and 40 mg of praziquantel (PZQ) per kg body weight for treatment of schistosomiasis is one of the strategies recommended by World Health Organization (WHO) in order to control the morbidity of soil-transmitted helminthiasis and schistosomiasis. Since storage condition, climate, way of transportation and distribution route could all affect the quality of medicines, regular assessment by surveys is very critical to ensure the therapeutic outcome, to minimize risk of toxicity to the patient and resistance of parasites. Therefore, this study was conducted to assess the pharmaceutical quality of ABZ, MBZ and PZQ tablet brands commonly available in Jimma town (south west Ethiopia). Retail pharmacies (n = 10) operating in Jimma town were selected using simple random sampling method. Samples of anthelminthic medicines available in the selected pharmacies were collected. Sample information was recorded and encompassed trade name, active ingredient name, manufacturer’s name and full address, labeled medicine strength, dosage form, number of units per container, dosage statement, batch/lot number, manufacturing and expiry dates, storage information and presence of leaflets/package insert. Moreover, a first visual inspection was performed encompassing uniformity of color, uniformity of size, breaks, cracks, splits, embedded surface spots or visual contaminations. Finally, physico-chemical quality attributes investigated encompassed mass uniformity, quantity of active pharmaceutical ingredient (API), disintegration and dissolution, all following Pharmacopoeial test methods The physical characteristics of dosage form, packaging and labeling information of all samples complied with criteria given in the WHO checklists. The mass uniformity of tablets of each brand of ABZ, MBZ and PZQ complied with the pharmacopoeial specification limits, i.e no more than 2 individual masses > 5% of average tablet weight, and none deviate by more than 10%. The quantity of APIs in all investigated tablet brands were within the 90–110% label claim (l.c.) limits, ranging between 95.05 and 110.09% l.c. Disintegration times were in line with the pharmacopoeial specification limit for immediate release (IR) tablets, ranging between 0.5 and 13 min. However, the dissolution results (mean ± SD, n = 6) of one ABZ brand (i.e. Wormin®, Q = 59.21 ± 0.99% at 30 min) and two PZQ brands (i.e. Bermoxel®, Q = 63.43% ± 0.7 and Distocide®, Q = 62.43% ± 1.67, at 75 min) showed poor dissolution, failing the United States Pharmacopoeia (USP) dissolution specification limit.
1. Introduction Neglected tropical diseases (NTDs) are affecting 500 million people living in Sub-Saharan Africa countries. In this region, NTDs are annually causing an estimated 534, 000 deaths and 57 million disabilityadjusted life years loss (Conteh et al., 2010). Ethiopia is one of the SubSaharan Africa countries, where different NTDs mainly schistosomiasis
and soil-transmitted helminthiasis are affecting millions of people living in endemic areas (Bajiro et al., 2016; Bitew et al., 2016; Dana et al., 2014; Mengistu et al., 2011). The prevalence of soil-transmitted helminths and schistosomiasis in Ethiopia is 48–52% (Tefera et al., 2017; Mekonnen et al., 2016) and 31–81% (Tadege and Shimelis, 2017; Bereket and Zewdneh, 2015), respectively. To reduce morbidity and eliminate NTDs by 2020, the World Health Organization (WHO)
⁎
Corresponding author. E-mail addresses: [email protected] (S. Belew), [email protected] (S. Suleman), [email protected] (E. Wynendaele), [email protected] (M. D’Hondt), [email protected] (A. Kosgei), [email protected] (L. Duchateau), [email protected] (B. De Spiegeleer). http://dx.doi.org/10.1016/j.actatropica.2017.10.006 Received 30 June 2017; Received in revised form 15 September 2017; Accepted 7 October 2017 Available online 13 October 2017 0001-706X/ © 2017 Elsevier B.V. All rights reserved.
Acta Tropica 177 (2018) 157–163
S. Belew et al.
checklist (WHO, 2015) designed to health professionals to carry out visual inspection of medicines for signs of counterfeiting and report to appropriate national authority or directly to WHO. All samples underwent visual inspection for trade name, active ingredient name, the manufacturer’s name and full address, labeled medicine strength, dosage form, number of units per container, dosage statement, batch/lot number, manufacturing and expiry dates, storage information, presence of leaflets/package insert. Moreover, a first visual inspection was performed encompassing uniformity of color, uniformity of size, breaks, cracks, splits, embedded surface spots or visual contaminations. Finally, samples were stored between 21.6 °C ± 1.09 as minimum and 22.09 °C ± 0.89 as maximum daily average temperature (mean ± SD, n = 119 days,), with a relative humidity (%RH) of 36.63% ± 7.04 until analysis.
recommends mass drug administration for at-risk populations as one of the best strategies (WHO, 2010). However, in low-income and middleincome countries, high prevalence of poor quality medicines (Caudron et al., 2008; Cohn et al., 2012; Fadeyi et al., 2015; Suleman et al., 2014) and failure of pharmaceutical distributors to apply stringent criteria for selecting products and suppliers (Giralt et al., 2017), are prevailing challenges in patient’s access to quality medicines. In Ethiopia, the existing weak regulatory enforcement, lack of informal market control, weak port control, poor cooperation between executive bodies and resource constraint (Suleman et al., 2016) and long border that Ethiopia shares with neighbouring countries, could contribute to infiltration of poor quality medicines into the pharmaceutical supply chain. Since poor quality of medicine is linked with reduced efficacy (Belew et al., 2015; Lacey, 1990; Leslie et al., 2009) and toxicity to patients (Peyraud et al., 2017), evaluating the quality of essential medicines is crucial for delivering quality health services. In Ethiopia, owing to the prevalence of schistosomiasis and soil-transmitted helminthiasis as well as other parasitic worms, different brands of anthelminthic medicines are indiscriminately used in the treatment of parasitic infections. However, there is little information about the quality of these medicines circulating in the market (Belew et al., 2015; Suleman et al., 2014). Therefore, this study was conducted to assess the quality of anthelminthic medicines encompassing ABZ, MBZ and PZQ tablets brands commonly available in legally operating retail pharmacies in Jimma town.
2.5. Mass uniformity
2. Materials and methods
The mass uniformity test was performed according to the method given in European Pharmacopoeia (Ph. Eur., 2014a). Randomly selected tablets (n = 20) from each brand of ABZ (Albenzole®, Ovis® and Wormin®), MBZ (Mebepharm®, Wormin® and Thelmox®) and PZQ (Bermoxel®, Distocide® and Praziquantel) were weighed using a calibrated analytical balance (Mettler Toledo, AB204-5, Switzerland). The average weight was calculated and the mass uniformity of tablets was evaluated against Pharmacopoeia specification limit (i.e. no more than 2 individual masses > 5% of the average tablet weight, and none deviating by more than 2 × 5% of the average tablet weight).
2.1. Survey area
2.6. Amount of API
The survey was conducted in Jimma town. Jimma town is located at 352 km from the capital Addis Ababa. According to Central Statistical Agency (CSA) report the projected population of Jimma zone from 2014 to 2017 is estimated to be 2,986,957 (CSA, 2013). Jimma is a relatively large town with nine legally operating wholesalers of pharmaceutical products which are currently supplying pharmaceutical products to retail pharmacies (n = 22), health centers (n = 4), clinics (n = 15) and hospitals (n = 2).
2.6.1. System suitability System suitability test was evaluated according to European Pharmacopoeia method (Ph. Eur., 2014b). The symmetry factor of principal peak of reference standard and percent relative standard deviation of replicate injections (6 times) of reference standard were calculated and compared against Pharmacopoeia specification limit i.e symmetry factor of the principal peak (0.8-1.5) and maximal permitted percent relative standard deviation (%RSD) of replicate injections (0.85).
2.2. Sample collection 2.6.2. Albendazole The amount of API of samples of ABZ tablets was investigated according to the United States Pharmacopoeia method (USP, 2015a).
From a total of 22 pharmacies officially operating in Jimma town, 10 pharmacies were selected using simple random sampling method. One box of anthelminthic was bought in each of retailing pharmacy resulting in samples for quality verification. One pharmacy did not have one of the requested anthelminthics. All samples were transported to Jimma University Laboratory of Drug Quality (JuLaDQ) on the same day of sample collection. In addition, survey on the sales volume and price of ABZ, MBZ and PZQ products available in legally operating wholesalers (n = 9) and retail pharmacies (n = 22) was conducted.
2.6.2.1. Preparation of standard solution. Approximately 100.0 mg of ABZ reference standard (RS) was accurately weighed into a 50.0 mL volumetric flask and dissolved in 5.0 mL of acidified methanol (sulfuric acid/methanol, 1/99% v/v). The prepared stock solution was diluted with methanol to volume and mixed. A volume of 5.0 mL of the solution was transferred into a second 50.0 mL volumetric flask and diluted with methanol to volume and mixed again.
2.3. Chemicals/reagents/solvents 2.6.2.2. Preparation of sample solution. Randomly selected tablets (n = 20) were finely powdered. A portion of powder equivalent to approximately 100.0 mg ABZ was transferred into a 50.0 mL volumetric flask, dissolved in 5.0 mL of acidified methanol (sulfuric acid/ methanol, 1/99% v/v), shaken for 15 min, diluted with methanol to volume, mixed and filtered with Whatman No. 1 filter paper by discarding the first 15.0 mL of the filtrate. A 5.0 mL of clear filtrate was transferred into a second 50.0 mL volumetric flask, diluted with methanol to volume and mixed.
ABZ (USP reference standard), MBZ (Janssen Pharmaceutica) and PZQ (Sigma-Aldrich) reference standards were used as received. Hydrochloric acid (37% w/v, Sigma-Aldrich), methanol (HPLC grade, Fishers Scientific), acetonitrile (HPLC grade, Fishers Scientific), orthophosphoric acid (Fluka Chemicals Ltd.), potassium phosphate monobasic (KH2PO4) (Sigma-Aldrich), ammonium phosphate monobasic (Sigma-Aldrich), sodium hydroxide (Sigma-Aldrich), sodium lauryl sulphate (Sigma-Aldrich) and ultra pure water (18.2 Ωcm) were used.
2.6.2.3. HPLC method. The samples were analyzed using HPLC equipped with a 254 nm UV–vis detector and a C18 column (4.6 mm x 25 cm, 5 μm) (Zorbax, Agilent). The mobile phase was a mixture of 0.50 g monobasic ammonium phosphate (NH4H2PO4) in 400.0 mL
2.4. Physical characteristics, packaging and labelling information Visual inspection of the physical characteristics of dosage form, packaging and labelling information was performed following the WHO 158
Acta Tropica 177 (2018) 157–163
S. Belew et al.
disintegration apparatus with disk (ERWEKA, GmbH, Germany). The test was performed for 15 min using a medium of 1000.0 mL de-ionized water at a temperature of 37 ± 0.5 °C and device’s basket raising and lowering frequency rate of 32 cycles/min.
water/methanol (40/60% v/v). The column temperature, injection volume and flow rate were 25 °C, 20.0 μL and 2.0 mL/min., respectively. 2.6.3. Mebendazole The amount of API was investigated according to the United States Pharmacopoeia method (USP, 2015b).
2.8. Dissolution 2.8.1. Albendazole The dissolution of tablet samples of each brand of ABZ was evaluated using a dissolution apparatus II (paddle) (Varian VK-7010 Dissolution apparatus, Agilent Technologies) following United States Pharmacopoeia test method for ABZ tablets (USP, 2015a). The test was performed for 45 min at a medium temperature and the spindle rotation speed of 37 ± 0.5 °C and 50 rpm, respectively. Six tablets, two from each brand of anthelminthics medicines were randomly assigned into the dissolution vessels containing a dissolution medium (900.0 mL 0.1 N HCl). A 10.0 mL samples was withdrawn at predetermined time points (15, 30, 45 min), immediately filtered using Whatman No. 1 filter paper and diluted in 250.0 mL volumetric flask with 0.1 N sodium hydroxide. The absorbance of each sample was determined at 308 and 350 nm using a UV/Visible spectrophotometer (Ultrospec-4000, Pharmacia Biotech) and the difference taken as absorbance value. A 0.1 N sodium hydroxide solution was used as the background. The quantity in milligram (mg) of dissolved ABZ was calculated by the formula 22.5 × C(Au/As), where C is the concentration of the ABZ reference standard (RS) in the standard solution (μg per mL) and Au and As are the absorbance differences, obtained at 308 and 350 nm, of the solution under test (Au) and the standard solution (As).
2.6.3.1. Preparation of standard solution. Approximately 25.0 mg of MBZ RS was transferred into a 100.0 mL volumetric flask and dissolved in 10.0 mL of formic acid and heated in a water bath at 50 °C for 15 min. The sample was mechanically shaken for 5.0 min, dissolved in 90.0 mL methanol and cooled. The solution was diluted to volume with methanol and mixed. A 5.0 mL of the solution was transferred to 25.0 mL volumetric flask, diluted with mobile phase to volume, mixed and filtered through a filter paper having a porosity of 0.5 μL. A 0.05 mg/mL of MBZ RS was prepared in mobile phase and used. 2.6.3.2. Preparation of sample solution. Randomly selected tablets (n = 20) were finely powdered. A portion of powder approximately equivalent to 500.0 mg MBZ was transferred into a 100.0 mL volumetric flask and dissolved in 50.0 mL of formic acid and heated in a water bath at 50 °C for 15 min. The flask was mechanically shaken for 1 h, diluted with water to volume, mixed and filtered with Whatman No. 1 filter paper. A 5.0 mL of the filtrate was transferred into a 100.0 mL volumetric flask and diluted with a solution of formic acid in methanol (formic acid/methanol, 1/9% v/v) to volume. Finally, 0.05 mg/mL of MBZ solution was prepared in mobile phase and used.
2.8.2. Mebendazole The dissolution of tablet samples of each brand of MBZ was evaluated using a dissolution apparatus II (paddle) (Varian VK-7010 Dissolution apparatus, Agilent Technologies) following United States Pharmacopoeia test method for MBZ tablets (USP, 2015b). The test was performed for 120 min at a medium temperature and the spindle rotation speed of 37 ± 0.5 °C and 75 rpm, respectively. Six tablets, two from each brand of anthelminthics medicines were randomly assigned into the dissolution vessels containing a dissolution medium (900.0 mL 0.1 N HCl containing 10 mg sodium lauryl sulphate per mL). A 10.0 mL samples was withdrawn at predetermined time points (30, 60, 90, 120 min) and immediately filtered using Whatman No. 1 filter paper. The samples were analyzed using HPLC equipped with 254 nm UV–vis detector and C-18 column (4.6 mm × 25 cm, 5 μ) (Microsorb Varian). The mobile phase used was mixture of acetonitrile (HPLC grade) and buffer solution (8.0 g of sodium hydroxide and 3.0 g of sodium lauryl sulphate in 2.0 L of water, pH of 2.5 adjust with phosphoric acid) (acetonitrile/buffer, 3/7% v/v). The column temperature, injection volume and flow rate were 25 °C, 10.0 μL and 1.0 mL/min, respectively.
2.6.3.3. HPLC method. The samples were analyzed using HPLC equipped with 247 nm UV–vis detector and a C18 column (4.6 mm × 25 cm, 5 μm) (Zorbax, Agilent). The mobile phase used was a mixture of 0.05 M monobasic potassium phosphate (KH2PO4) and methanol (0.05 M monobasic potassium phosphate/methanol, 40/60% v/v, pH = 5.5). The column temperature, injection volume and flow rate were 30 °C, 15.0 μL and 1.5 mL/min., respectively. 2.6.4. Praziquantel 2.6.4.1. Preparation of standard solution. The amount of API was investigated according to the United States Pharmacopoeia method (USP, 2015c). An accurately weighed amount of PZQ RS was dissolved in mobile phase (acetonitrile/water, 60/20% v/v) to obtain a solution having a concentration of about 0.18 mg/mL. 2.6.4.2. Preparation of sample solution. Randomly selected tablets (n = 20) were finely powdered. A portion of powder approximately equivalent to 150.0 mg PZQ was transferred into a 100.0 mL volumetric flask, dissolved in 70.0 mL mobile phase (acetonitrile/water, 60/40% v/v), sonicated for 5 min, diluted with mobile phase to volume, mixed and filtered with Whatman No. 1 filter paper. A volume of 3.0 mL of the filtrate was transferred into a 25.0 mL volumetric flask and diluted with mobile phase to volume and used.
2.9. Praziquantel The dissolution of tablet samples of each brand of PZQ was evaluated using a dissolution apparatus II (paddle) (Varian VK-7010 Dissolution apparatus, Agilent Technologies) following United States Pharmacopoeia test method for PZQ tablets (USP, 2015c). The test was performed for 75 min at a medium temperature and the spindle rotation speed of 37 ± 0.5 °C and 50 rpm, respectively. Six tablets, two from each brand of anthelminthics medicines were randomly assigned into the dissolution vessels containing a dissolution medium (900.0 mL 0.1 N HCl containing 2.0 mg of sodium lauryl sulphate per mL). A 10.0 mL samples was withdrawn at predetermined time points (15, 30, 60, 75 min) and immediately filtered using Whatman No. 1 filter paper. The amount of PZQ dissolved was determined at an absorbance wave length of 263 nm using a UV/Visible spectrophotometer (Ultrospec4000, Pharmacia Biotech).
2.6.4.3. HPLC method. The samples were analyzed using HPLC equipped with 210 nm UV–vis detector and a C18 column (4.6 mm x 25 cm, 5 μm) (Hypersil ODS, Thermo Scientific). The mobile phase used was a mixture of acetonitrile/water (60/40% v/v). The column temperature, injection volume and flow rate were 30 °C, 10.0 μL and 1.5 mL/min., respectively. 2.7. Disintegration The disintegration test was performed according to the European Pharmacopoeia (Ph. Eur., 2014c). Six tablets from each brand of ABZ, MBZ and PZQ were randomly selected and placed into tubes of the 159
Acta Tropica 177 (2018) 157–163
S. Belew et al.
3. Results
Table 2 Results of quantity of API of tablet samples (n = 20) of ABZ, MBZ and PZQ brands.
The survey results on weekly sales volume of anthelminthic medicines in legally operating wholesalers (n = 9) and retail pharmacies (n = 22) (S3 Table) revealed that the products of ABZ, MBZ and PZQ sampled for this study account for respectively 27, 60 and 100% of the products of each API of anthelminthic medicines available in Jimma. In addition, the weekly sales data of anthelminthic medicines in retail pharmacies in Jimma indicate that relatively large numbers of dosage units (n = 12,144) of the investigated products are dispensed per week. The price of the investigated products is presented in S4 Table. Considering the doses recommended by WHO, the average (n = 3) price per treatment of ABZ, MBZ and PZQ is 0.20, 0.45 and 0.40 USD, respectively. This shows that an average estimated minimum and maximum cost of the investigated anthelminthic medicines per treatment is 4.72 and 10.63 Ethiopian Birr (ETB), respectively.
% lable claim (%RSD, n = 2)a
Product Albendazole Albezole® 400 mg Ovis® 400 mg Wormin® 400 mg endazole Mebepharm® 100 mg Wormin® 100 mg Thelmox® 100 mg Praziquantel Bermoxel® 600 mg Distocide® 600 mg Praziquantel 600 mg a
97.74 (0.19) 96.88 (1.51) 95.05 (0.98) 102.53 (0.00) 108.24 (0.41) 110.09 (0.01) 99.46 (0.02) 96.83 (0.02) 102.12 (0.04)
number of injections.
Table 3 Disintegration time ranges of tablet samples (n = 6) of different brands of ABZ, MBZ and PZQ tablets.
3.1. Physical characteristics of tablets, packaging and labelling The results of visual inspection on physical characteristics, packaging and labelling information of samples of each brand of ABZ, MBZ and PZQ are presented in supplementary information table (S1 Table). The price of the investigated anthelminthic medicines is presented in supplementary information table (S4 Table). The results of visual inspection on physical characteristics of dosage form, packaging and labeling revealed that all samples did not show signs of counterfeit medicines defined by WHO.
Product name
API
Time range (min)
Albendazole Albezole® 400 mg Ovis® 400 mg Wormin® 400 mg
5.0–8.0 10.0–13.0 8.0–12.0 Mebendazole
Mebepharm® 100 mg Wormin® 100 mg Thelmox® 100 mg
3.2. Mass uniformity
1.0–1.5 1.0–1.1 3.0–4.0 Praziquantel
Bermoxel® 600 mg Distocide® 600 mg Praziquantel 600 mg
The mass uniformity results (Table 1) of tablet samples of each brand of ABZ, MBZ and PZQ were within the European Pharmacopoeia specification limit (i.e. no more than 2 individual masses > 5% of the average tablet weight and none deviating by more than 10% of the average tablet weight).
1.0–2.0 9.0–11.0 0.5–1.0
3.5. Dissolution The dissolution profile (mean ± SD, n = 6) of tablet brands of ABZ, MBZ and PZQ (Fig. 1A–C) revealed that two PZQ brands (i.e Bermoxel®, Q = 63.43 ± 0.70, Distocide®, Q = 62.43 ± 1.67) and one ABZ brand (i.e Wormin®, Q = 59.21 ± 0.99) failed to comply with the USP specification limits (i.e. ABZ: Q ≤ 80% at 30 min, MBZ: Q ≤ 75% at 120 min, PZQ: Q ≤ 75% at 60 min).
3.3. Amount of active pharmaceutical ingredient The assay results (Table 2) of API (mean ± SD% l.c.) showed that samples of all anthelminthic brands comply with the USP specification limit (90–110% l.c.). The percent relative standard deviation (%RSD) values (< 2%) of all samples indicated adequate analytical precision. 3.4. Disintegration
4. Discussion
The results of disintegration time (Table 3) of all product samples complied with the specification limits given in the European Pharmacopoeia (i.e complete disintegration of immediate release (IR) tablets ≤ 15 min).
Evaluating the quality of medicines circulating in the market is important to reduce risk of having poor quality medicines in the supply chain. In this study, we assessed the pharmaceutical quality of commonly available brands of ABZ, MBZ and PZQ tablets in Jimma town.
Table 1 Mass uniformity results of samples of different brands of ABZ, MBZ and PZQ tablets. Product Albendazole Albezole® 400 mg Wormin® 400 mg Ovis® 400 mg Mebendazole Mebepharm® 100 mg Wormin® 100 mg Thelmox® 100 mg Praziquantel Bermoxel® 600 mg Distocide® 600 mg Praziquantel 600 mg
Average tablet weight (mg) (n = 20)
Range of tablet weight (mg)
%RSD (n = 20)
LV – UV (mg)
1039.4 685.1 698.5
996.2–1078.1 670.4–696.2 679.7–729.3
0.12 0.07 0.11
987.4–1091.4 650.8–719.3 663. 6–733.4
262 302.6 315
248.7–270.6 289.5–308.6 313.9–318.1
0.11 0.1 0.01
248.9–275.1 287.4–317.7 299.3–330.8
734.7 910.1 747.9
721.4–742.2 884.1–929.8 737.7–767.9
0.03 0.07 0.05
697.9–771.4 864.6–955.6 710.5–785.5
%RSD: percent relative standard deviation; LV: lower limit; UV: upper limit.
160
Acta Tropica 177 (2018) 157–163
S. Belew et al.
Fig. 1. Dissolution profile (Mean ± SD, n = 6) of (A) ABZ tablet brands in 900 mL 0.1N HCl (37 ± 0.5 °C, rpm = 50), (B) MBZ tablet brands in 900 mL 0.1N HCl containing 1% sodium lauryl sulphate (37 ± 0.5 °C, rpm = 75) and (C) PZQ tablet brands in 900 mL 0.1N HCl containing 2.0 mg/mL sodium lauryl sulphate (37 ± 0.5 °C, rpm = 50) using a USP II apparatus.
RDZ® and Bendex® showed an egg reduction rate ranging between 91.9 and 98.7% against round worm (Ascaris lumbricoides), which is almost similar to the percent egg reduction rate observed for Zentel® (92.6%) and Ovis® (97.8%) (Albonico et al., 2007; Belew et al., 2015). This suggests that dissolution might not have an equally significant effect for roundworms as for hookworms. The differences in efficacy results observed against hookworm and roundworm might be attributed to the differences in feeding behaviour and/or routes of nutrient uptake between the two parasites (Gilbert, 1996; John et al., 2004; Skelly et al., 2014). This suggests that the in-vivo relevance of the in-vitro dissolution will depend on parasite type, with its life cycle, the medicine uptake mechanism and the internal parasite medicine pharmacology. Poor dissolution may thus not necessarily and automatically be linked to a reduced efficacy in all helminth parasitic species. Different mechanisms such as active efflux, reduced drug uptake, drug modification, drug sequestration, by-pass shunt of helminth parasites (Ouellette, 2001) should be taken into consideration for the in vitro-in vivo relationship (IVIVC). However, the concept of ‘substandard’ drugs, defined as ‘genuine medicines produced by the manufacturers authorized by the national medicines regulatory authority which do not meet quality specifications set for them by national standards’ (WHO, 2009) is not directly and automatically linked to IVIVC. Both aspects, i.e the regulatory standards based on quality consistency as well as the clinical relevance, are to be considered in the overall evaluation. Ideally, both aspects should be consistent; however, currently, due to the absence of well developed PK-PD models, there is not yet proof of this consistency, remaining a challenge for future research. Generally, since dissolution is a critical quality attribute, the poor dissolution of investigated medicines, could minimize the clinical efficacy and pose a challenge in chemotherapeutic approach which is one of the strategies that Ethiopia has been implementing to prevent, control and eliminate NTD by 2020 (FMoH, 2016). In addition, the poor quality of medicines could have a negative impact on some of the progress in Ethiopia that has been made in prevention, control and elimination of soil-transmitted helminths and schistosomiasis so far (Nebiyu et al., 2017). Moreover, poor quality of investigated anthelminthic medicines could increase the risk of drug resistance (Newton et al., 2010). Furthermore, since legally operating retail pharmacies in Jimma are dispensing relatively large numbers of dosage units (n = 12,144) of the investigated anthelminthic medicines per week, the poor dissolution of these medicines could have a negative impact on the recovery of a significant number of patients infected with STHs, schistosomiasis and other gastrointestinal worms.
The results of visual inspection of packaging and labelling information on the tested brands of ABZ, MBZ and PZQ tablets did not show signs of spurious, falsely labelled, falsified or counterfeit products as defined by WHO (WHO, 2009). This suggests that packaging and labeling information of each brand of anthelminthic medicines is in line with WHO guideline on packaging for pharmaceutical products (WHO, 2002). The results of mass uniformity of tablet samples of all anthelminthic medicines comply with pharmacopoeia specification limit (Ph. Eur., 2014a) (i.e. no more than 2 individual masses > 5% of the average tablet weight and none deviating by more than 2 × 5% of the average tablet weight). Though the mass uniformity results comply with pharmacopoeia specification limit, the presence of outlier tablets indicates inconsistency of tablet manufacturing process (Adeley et al., 2014). For a single dose preparation, variations in mass of tablets could influence uniformity of API and/or entire composition of a dosage unit. According to USP tablets of ABZ, MBZ and PZQ should contain the required amount of API (%l.c. = 90–110%) (USP, 2015a,b,c). The assay results of API (mean ± SD% l.c.) of all tablet samples of anthelminthic brands complied with the Pharmacopoeial specification limit. Thus, with respect to amount of API, interchangeable use of tablet brands containing the same API will most probably result in a similar clinical efficacy. Also, the assay results suggest that there is not a significant quality difference in the different tablet samples. The disintegration times complied with the pharmacopoeial specification limit (complete disintegration of IR tablets ≤ 15 min). However, 3–4 min disintegration time difference was observed in a set of samples of all ABZ tablet brands and one PZQ tablet brand (Distocide®). Moreover, Distocide® showed longer disintegration time (9–11 min) compared with the other praziquantel tablet brands (0.5–2 min). This might be attributed to variations in the manufacturing process and/or differences in the type and amount of excipient used (King Chiu et al., 1957). Considering the single point dissolution specification (mean ± SD, n = 6), one third of the tablet samples (one ABZ brand (Wormin®, Q = 59.21 ± 0.99) and two PZQ brands (Bermoxel®, Q = 63.43 ± 70 and Distocide®, Q = 62.43 ± 1.67)) failed to comply with the USP acceptance criteria (USP, 2015a,c) (i.e. ABZ: Q ≥ 80% at 30 min and PZQ: Q ≥ 75% at 60 min). For Biopharmaceutical Classification System (BCS) class II drugs like ABZ, MBZ and PZQ, dissolution is a rate limiting factor for absorption into the blood but assumed also into the parasite system (Takano et al., 2008). Thus, poor dissolution could be a risk of reduced efficacy. Indeed, it has been shown that ABZ tablet brands (Azol®, RDZ® and Bendex®) which failed to comply with the USP acceptance criteria for dissolution (Q ≥ 80 at 30 min) showed low percent egg reduction rate (i.e. RDZ®: 80.8%, Azol®: 73.1% and Bendex®: 88.7%) against hookworm (Ancylostoma duodenale or Necator americanus), while other brands (Zentel® and Ovis®) which did comply with the dissolution specification demonstrated relatively high percent egg reduction rate (i.e. Zentel®: 87.1% and Ovis®: 98.1%). On the other hand, having poor dissolution, Azol®,
5. Conclusion The results of the present study showed that all the samples of each brand of ABZ, MBZ and PZQ tablets complied with the pharmacopeial specification acceptance criteria for packaging and labeling information, mass uniformity, amount of API and disintegration. However, one 161
Acta Tropica 177 (2018) 157–163
S. Belew et al.
Substandard medicines in resource‐poor settings: a problem that can no longer be ignored. Trop. Med. Int. Health. Available at: http://onlinelibrary.wiley.com/doi/10. 1111/j.1365-3156.2008.02106.x/full. (Accessed 16 June 2017). Cohn, J., Schoen-Angerer, T.V., Jambert, E., Arreghini, G., Childs, M., 2012. When falsified medicines enter the supply chain: description of an incident in Kenya and lessons learned for rapid response. J. Public Health Policy 34, 22–30. http://dx.doi. org/10.1057/jphp.2012.53. Conteh, L., Thomas, E., Molyneux, D., 2010. Socioeconomic aspects of neglected tropical diseases. Lancet 375, 239–247. Central Statistical Agency (CSA). Federal Democratic Republic of Ethiopia. Federal Democratic Republic of Ethiopia Central Statistical Agency population projection of Ethiopia for all regions at wereda level from 2014-2017, 2013. Available at: www. csa.gov.et/index.php/ehioinfo-internal?download=724:population. (Accessed: 16/ 06/2016). Dana, D., Mekonnen, Z., Emana, D., Ayana, M., Getachew, M., Workneh, N., Vercruysse, J., Levecke, B., 2014. Prevalence and intensity of soil-transmitted helminth infections among pre-school age children in 12 kindergartens in Jimma town, southwest Ethiopia. Trans. R. Soc. Trop. Med. Hyg. 109, 225–227. http://dx.doi.org/10.1093/ trstmh/tru178. Federal Ministry of Health (FMoH), 2016. The second edition of Neglected Tropical Diseases Master Plan 2015/2016. Federal democratic republic of Ethiopia, Addis Ababa. Available at: https://www.medbox.org/national-neglected-tropical-diseasesmaster/download.pdf. (Accessed 03 September 2017). Fadeyi, I., Kaur, H., Lalani, M., Mailk, N., Wyk, A.V., 2015. Quality of the antibiotics—amoxicillin and co-trimoxazole from Ghana, Nigeria, and the United Kingdom. Am. J. Trop. Med. Hyg. 92 (6 Suppl), 87–94. http://dx.doi.org/10.4269/ ajtmh.14-0539. Gilbert, A.C., 1996. Medical microbiology 4th edition. Helminths: Structure, Classification, Growth, and Development Available at: www. ncbi. nlm. nih. gov/ books/NBK8282 (Accessed 15 June 2017). Giralt, A.N., Schiavetti, B., Meessen, B., Pouget, C., Caudron, J.M., Marchal, B., Massat, P., Thys, S., Ravinetto, R., 2017. Quality assurance of medicines supplied to low-income and middle-income countries: poor products in shiny boxes? BMJ Glob. Health 2 (2). http://dx.doi.org/10.1136/bmjgh-2016-000172. John, P.D., Patrick, S., David, W.H., 2004. Role of tegument and gut in nutrient uptake by parasitic platyhelminths. Can. J. Zool. 82, 211–232. King Chiu, K., Fred, O.S., Albert, M.M., 1957. Factors affecting tablet disintegration. J. Pharm. Sci. 46, 236–239. Lacey, E., 1990. Mode of action of benzimidazoles. Parasitol. Today 6, 112–115. http:// dx.doi.org/10.1016/0169-4758(90)90227-u. Leslie, T., Kaur, H., Mohammed, N., Kolaczinski, K., Ord, R.L., Rowland, M., 2009. Epidemic of Plasmodium falciparum malaria involving substandard antimalarial drugs, Pakistan, 2003. Emerg. Infect. Dis. 15, 1753–1759. http://dx.doi.org/10. 3201/eid1511.090886. Mekonnen, Z., Suleman, S., Biruksew, A., Tefera, T., Chelkeba, L., 2016. Intestinal polyparasitism with special emphasis to soil-transmitted helminths among residents around Gilgel Gibe Dam, southwest Ethiopia: a community based survey. BMC Public Health 16, 1185. Mengistu, M., Shimelis, T., Torben, W., Terefe, A., Kassa, T., Hailu, A., 2011. Human intestinal schistosomiasis in communities living near three rivers of Jimma town, south western Ethiopia. Ethiop. J. Health Sci. 21. http://dx.doi.org/10.4314/ejhs. v21i2.69051. Nebiyu, N., Birhan, M., Biruck, K., Kebede, D., Ephrem, E., Gemechu, T., Kalkidan, M., Mesfin, S., 2017. Ethiopia schistosomiasis and soil-transmitted helminthes control programme: progress and prospects. Ethiop. Med. J. 55 (Suppl. 1). Newton, P.N., Michael, D.G., Facundo, M.F., 2010. Impact of poor-quality medicines in the ‘developing’ world. Trends Pharmacol. Sci. 31, 99–101. http://dx.doi.org/10. 1016/j.tips.2009.11.005. Ouellette, M., 2001. Biochemical and molecular mechanisms of drug resistance in parasite. Trop. Med. Int. Health 6, 874–882. Peyraud, N., Rafael, F., Parker, L.A., Quere, M., Alcoba, G., Korff, C., Gabriel, A., Christian, K., Michael, D., Pernette, B.E., Jean-Clément, C., Micaela, S., Iza, C., Monica, R., Islam Amine, L., Frédéric, B., Francesco, G., Benoit, K.I., Jean-Claude, A., Newton, P.N., 2017. An epidemic of dystonic reactions in central Africa. Lancet Glob. Health 5 (2). http://dx.doi.org/10.1016/s2214-109x(16)30287-x. European Pharmacopoeia (Ph. Eur.), 2014a. Uniformity of Mass of Single Dose Preparations, 8th ed. European Directorate for Quality of Medicines and Health care, Strasbourg, France, pp. 297–298. European Pharmacopoeia (Ph. Eur.), 2014b. 2.2.46. Chromatographic Separation Techniques, 8th ed. European Directorate for Quality of Medicines and Health care, Strasbourg, France, pp. 72–79. European Pharmacopoeia (Ph. Eur.), 2014c. Disintegration of Tablets and Capsules, 8th ed. European Directorate for Quality of Medicines and Health care, Strasbourg, France, pp. 225–227. Skelly, P.J., Dadara, A.A., Li, X., Castro-Borges, W., Wilson, R.A., 2014. Schistosome feeding and regurgitation. PLoS Pathog. 10. http://dx.doi.org/10.1371/journal.ppat. 1004246. Suleman, S., Zeleke, G., Deti, H., Mekonnen, Z., Duchateau, L., Levecke, B., Jozef, V., D'Hondt, M., Evelien, W., Spiegeleer, B.D., 2014. Quality of medicines commonly used in the treatment of soil transmitted helminths and giardia in Ethiopia: a nationwide survey. PLoS Negl. Trop. Dis. 8. http://dx.doi.org/10.1371/journal.pntd. 0003345. Suleman, S., Woliyi, A., Woldemichael, K., Tushune, K., Duchateau, L., Degroote, A., Roy, V., Nathalie, B., De Spiegeleer, B., 2016. Pharmaceutical regulatory framework in Ethiopia: a critical evaluation of its legal basis and implementation. Ethiop. J. Health Sci. 26, 259. http://dx.doi.org/10.4314/ejhs.v26i3.9.
third of samples failed to comply with the pharmacopoeial specification limit set for dissolution test. In general, the results of this study suggest that anthelminthic medicines circulating in the market could have risk of reduced efficacy. Therefore, poor quality of medicines could influence the chemotherapeutic intervention approach in reducing morbidity caused by soil-transmitted helminths and schistosomiasis. Thus, continuous monitoring, in a systematic way, the quality of anthelminthic medicines circulating in the market is recommended. Conflict of interest Authors declare no conflict of interest. Authors’ contribution Conceived and designed the experiments: BDS MD EW LD SS SB. Performed the experiments: SB, SS, MD, EW. Analyzed the data: BDS, LD, SB, EW, AK. Contributed reagents/materials/analysis tools: BDS, MD, LD, SS. Wrote the paper: BDS, MD, EW, LD, SS, SB, AK. Funding BOF (Special Research Fund) is funding a PhD scholarship of Sileshi Belew in Gent University (Scholarship code 01W03714, Reference number DOZA/ILDDC/AM/0866b-2014). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Acknowledgement The authors would like to thank Laboratory of Drug Quality and Registration (DruQaR), Gent University, Belgium for the provision of the reference substances. Additionally, we would like to thank the staff of the Laboratory of Drug Quality of Jimma University (JuLaDQ) (Markos Duguma, Henok Teshome, Tesfaye Mohammed and Yimer Mekonnen) for their kind support and collaboration. Appendix A. Supplementary data Supplementary data associated with this article can be found, in the online version, at http://dx.doi.org/10.1016/j.actatropica.2017.10. 006. References Adeleye, O.A., Femi-Oyewo, M.N., Odeniyi, M.A., 2014. The effect of processing variables on the mechanical and release properties of tramadol matrix tablets incorporating cissus populnea gum as controlled release excipient. Polim. Med. 44, 209–220. Albonico, M., Mathema, P., Montresor, A., Khakurel, B., Reggi, V., Pandey, S., Savioli, L., 2007. Comparative study of the quality and efficacy of originator and generic albendazole for mass treatment of soil-transmitted nematode infections in Nepal. Trans. R. Soc. Trop. Med. Hyg. 101, 454–460. http://dx.doi.org/10.1016/j.trstmh.2006.09. 003. Bajiro, M., Dana, D., Ayana, M., Emana, D., Mekonnen, Z., Zawdie, B., Asfaw, G., Ashenafi, K., Zeynudin, A., 2016. Prevalence of Schistosoma mansoni infection and the therapeutic efficacy of praziquantel among school children in Manna district, Jimma zone, southwest Ethiopia. Parasit. Vectors 9, 560. http://dx.doi.org/10.1186/ s13071-016-1833-6. Belew, S., Getachew, M., Suleman, S., Mohammed, T., Deti, H., Dhondt, M., Wynendaele, E., Mekonnen, Z., Vercruysse, J., Duchateau, L., De Spiegeleer, B., Levecke, B., 2015. Assessment of efficacy and quality of two albendazole brands commonly used against soil-transmitted helminth infections in school children in Jimma town, Ethiopia. PLoS Negl. Trop. Dis. 9 (9). http://dx.doi.org/10.1371/journal.pntd.0004057. Bereket, A., Zewdneh, T., 2015. Schistosoma mansoni Schistosoma mansoni infection prevalence and associated risk factors among schoolchildren in Demba Girara, Damot Woide District of Wolaita Zone, southern Ethiopia. Asian Pac. J. Trop. Med. 8, 457–463. Bitew, A.A., Abera, B., Seyoum, W., Endale, B., Kiber, T., Goshu, G., Admass, A., 2016. Soil-transmitted helminths and Schistosoma mansoni infections in Ethiopian Orthodox Church students around lake tana, northwest Ethiopia. PLoS One 11 (5). http://dx.doi.org/10.1371/journal.pone.0155915. Caudron, J., Ford, N., Henkens, M., Mace, C., Kiddle-Monroe, R., Pinel, J., 2008.
162
Acta Tropica 177 (2018) 157–163
S. Belew et al.
United States Pharmacopoeia, 2015c. USP 38/NF 33. USP Monographs: Praziquantel Tablets. The United States Pharmacopoeial Convention, 12601 Twinbrook Parkway, Rockville, MD, USA pp. 4969. World Health Organization (WHO), 2002. Technical Report Series No 902. Annex 9 Guideline on Packaging for Pharmaceutical Products. Thirty-sixth Report. World Health Organization, Geneva. Available at: http://apps.who.int/medicinedocs/en/d/ Jh3009e/. (Accessed 14 June 2017). World Health Organization (WHO), 2009. Counterfeit Medicines: Frequently Asked Questions. Available at http://www.who.int/medicines/services/counterfeit/faqs/ QACounterfeit-October2009.pdf. (Accessed 12 March 2015). World Health Organization (WHO), 2010. First WHO report on Neglected Tropical Diseases: working to overcome the global impact of neglected tropical diseases. . Available at: http://apps.who.int/iris/bitstream/10665/44440/1/9789241564090_ eng.pdf. (Accessed 16/06/2017). World Health Organization (WHO), 2015. Tool for Visual Inspection of Medicines. A Checklist for Visual Inspection of Medicines in Order to Identify Suspicious Products for Further Examination. Available at: http://www.whpa.org/toolkit_beaware_ inspection.pdf. (Accessed 16 February 2015).
Tadege, B., Shimelis, T., 2017. Infections with Schistosoma mansoni and geohelminths among school children dwelling along the shore of the Lake Hawassa, southern Ethiopia. PLoS One 12 (7), e0181547. http://dx.doi.org/10.1371/journal.pone. 0181547. Takano, R., Furumoto, K., Shiraki, K., Takata, N., Hayashi, Y., Aso, Y., Yamashita, S., 2008. Rate-limiting steps of oral absorption for poorly water-soluble drugs in dogs; prediction from a mini scale dissolution test and a physiologically-based computer simulation. Pharm. Res. 25, 2334–2344. http://dx.doi.org/10.1007/s11095-0089637-9. Tefera, E., Belay, T., Mekonnen, S.K., Zeynudin, A., Belachew, T., 2017. Prevalence and intensity of soil-transmitted helminths among school children of Mendera elementary school, Jimma, southwest Ethiopia. Pan Afr. Med. J. 27, 88. http://dx.doi.org/10. 11604/pamj. United States Pharmacopoeia, 2015a. USP 38/NF 33. USP Monograph: Albendazole Tablets. The United States Pharmacopoeial Convention, 12601 Twinbrook Parkway, Rockville, MD, USA pp. 2067. United States Pharmacopoeia, 2015b. USP 38/NF 33. USP Monographs: Mebendazole Tablets. The United States Pharmacopoeial Convention, 12601 Twinbrook Parkway, Rockville, MD, USA pp. 4210.
163
Contents lists available at ScienceDirect
Acta Tropica journal homepage: www.elsevier.com/locate/actatropica
Quality of anthelminthic medicines available in Jimma Ethiopia a,b
b
a
a
MARK a
Sileshi Belew , Sultan Suleman , Evelien Wynendaele , Matthias D’Hondt , Anne Kosgei , ⁎ Luc Duchateauc, Bart De Spiegeleera, a b c
Drug Quality and Registration (DruQuaR) Group, Faculty of Pharmaceutical Sciences, Ghent University, Ottergemsesteenweg 460, B-9000 Ghent, Belgium School of Pharmacy, Jimma University, PO Box 378, Jimma, Ethiopia Department of Biometrics, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, B-9820 Merelbeke, Belgium
A R T I C L E I N F O
A B S T R A C T
Keywords: Anthelminthics Ethiopia Pharmaceutical quality Survey
Soil-transmitted helminthiasis and schistosomiasis are major public health problems in Ethiopia. Mass deworming of at-risk population using a single dose administration of 400 mg albendazole (ABZ) or 500 mg mebendazole (MBZ) for treatment of common intestinal worms and 40 mg of praziquantel (PZQ) per kg body weight for treatment of schistosomiasis is one of the strategies recommended by World Health Organization (WHO) in order to control the morbidity of soil-transmitted helminthiasis and schistosomiasis. Since storage condition, climate, way of transportation and distribution route could all affect the quality of medicines, regular assessment by surveys is very critical to ensure the therapeutic outcome, to minimize risk of toxicity to the patient and resistance of parasites. Therefore, this study was conducted to assess the pharmaceutical quality of ABZ, MBZ and PZQ tablet brands commonly available in Jimma town (south west Ethiopia). Retail pharmacies (n = 10) operating in Jimma town were selected using simple random sampling method. Samples of anthelminthic medicines available in the selected pharmacies were collected. Sample information was recorded and encompassed trade name, active ingredient name, manufacturer’s name and full address, labeled medicine strength, dosage form, number of units per container, dosage statement, batch/lot number, manufacturing and expiry dates, storage information and presence of leaflets/package insert. Moreover, a first visual inspection was performed encompassing uniformity of color, uniformity of size, breaks, cracks, splits, embedded surface spots or visual contaminations. Finally, physico-chemical quality attributes investigated encompassed mass uniformity, quantity of active pharmaceutical ingredient (API), disintegration and dissolution, all following Pharmacopoeial test methods The physical characteristics of dosage form, packaging and labeling information of all samples complied with criteria given in the WHO checklists. The mass uniformity of tablets of each brand of ABZ, MBZ and PZQ complied with the pharmacopoeial specification limits, i.e no more than 2 individual masses > 5% of average tablet weight, and none deviate by more than 10%. The quantity of APIs in all investigated tablet brands were within the 90–110% label claim (l.c.) limits, ranging between 95.05 and 110.09% l.c. Disintegration times were in line with the pharmacopoeial specification limit for immediate release (IR) tablets, ranging between 0.5 and 13 min. However, the dissolution results (mean ± SD, n = 6) of one ABZ brand (i.e. Wormin®, Q = 59.21 ± 0.99% at 30 min) and two PZQ brands (i.e. Bermoxel®, Q = 63.43% ± 0.7 and Distocide®, Q = 62.43% ± 1.67, at 75 min) showed poor dissolution, failing the United States Pharmacopoeia (USP) dissolution specification limit.
1. Introduction Neglected tropical diseases (NTDs) are affecting 500 million people living in Sub-Saharan Africa countries. In this region, NTDs are annually causing an estimated 534, 000 deaths and 57 million disabilityadjusted life years loss (Conteh et al., 2010). Ethiopia is one of the SubSaharan Africa countries, where different NTDs mainly schistosomiasis
and soil-transmitted helminthiasis are affecting millions of people living in endemic areas (Bajiro et al., 2016; Bitew et al., 2016; Dana et al., 2014; Mengistu et al., 2011). The prevalence of soil-transmitted helminths and schistosomiasis in Ethiopia is 48–52% (Tefera et al., 2017; Mekonnen et al., 2016) and 31–81% (Tadege and Shimelis, 2017; Bereket and Zewdneh, 2015), respectively. To reduce morbidity and eliminate NTDs by 2020, the World Health Organization (WHO)
⁎
Corresponding author. E-mail addresses: [email protected] (S. Belew), [email protected] (S. Suleman), [email protected] (E. Wynendaele), [email protected] (M. D’Hondt), [email protected] (A. Kosgei), [email protected] (L. Duchateau), [email protected] (B. De Spiegeleer). http://dx.doi.org/10.1016/j.actatropica.2017.10.006 Received 30 June 2017; Received in revised form 15 September 2017; Accepted 7 October 2017 Available online 13 October 2017 0001-706X/ © 2017 Elsevier B.V. All rights reserved.
Acta Tropica 177 (2018) 157–163
S. Belew et al.
checklist (WHO, 2015) designed to health professionals to carry out visual inspection of medicines for signs of counterfeiting and report to appropriate national authority or directly to WHO. All samples underwent visual inspection for trade name, active ingredient name, the manufacturer’s name and full address, labeled medicine strength, dosage form, number of units per container, dosage statement, batch/lot number, manufacturing and expiry dates, storage information, presence of leaflets/package insert. Moreover, a first visual inspection was performed encompassing uniformity of color, uniformity of size, breaks, cracks, splits, embedded surface spots or visual contaminations. Finally, samples were stored between 21.6 °C ± 1.09 as minimum and 22.09 °C ± 0.89 as maximum daily average temperature (mean ± SD, n = 119 days,), with a relative humidity (%RH) of 36.63% ± 7.04 until analysis.
recommends mass drug administration for at-risk populations as one of the best strategies (WHO, 2010). However, in low-income and middleincome countries, high prevalence of poor quality medicines (Caudron et al., 2008; Cohn et al., 2012; Fadeyi et al., 2015; Suleman et al., 2014) and failure of pharmaceutical distributors to apply stringent criteria for selecting products and suppliers (Giralt et al., 2017), are prevailing challenges in patient’s access to quality medicines. In Ethiopia, the existing weak regulatory enforcement, lack of informal market control, weak port control, poor cooperation between executive bodies and resource constraint (Suleman et al., 2016) and long border that Ethiopia shares with neighbouring countries, could contribute to infiltration of poor quality medicines into the pharmaceutical supply chain. Since poor quality of medicine is linked with reduced efficacy (Belew et al., 2015; Lacey, 1990; Leslie et al., 2009) and toxicity to patients (Peyraud et al., 2017), evaluating the quality of essential medicines is crucial for delivering quality health services. In Ethiopia, owing to the prevalence of schistosomiasis and soil-transmitted helminthiasis as well as other parasitic worms, different brands of anthelminthic medicines are indiscriminately used in the treatment of parasitic infections. However, there is little information about the quality of these medicines circulating in the market (Belew et al., 2015; Suleman et al., 2014). Therefore, this study was conducted to assess the quality of anthelminthic medicines encompassing ABZ, MBZ and PZQ tablets brands commonly available in legally operating retail pharmacies in Jimma town.
2.5. Mass uniformity
2. Materials and methods
The mass uniformity test was performed according to the method given in European Pharmacopoeia (Ph. Eur., 2014a). Randomly selected tablets (n = 20) from each brand of ABZ (Albenzole®, Ovis® and Wormin®), MBZ (Mebepharm®, Wormin® and Thelmox®) and PZQ (Bermoxel®, Distocide® and Praziquantel) were weighed using a calibrated analytical balance (Mettler Toledo, AB204-5, Switzerland). The average weight was calculated and the mass uniformity of tablets was evaluated against Pharmacopoeia specification limit (i.e. no more than 2 individual masses > 5% of the average tablet weight, and none deviating by more than 2 × 5% of the average tablet weight).
2.1. Survey area
2.6. Amount of API
The survey was conducted in Jimma town. Jimma town is located at 352 km from the capital Addis Ababa. According to Central Statistical Agency (CSA) report the projected population of Jimma zone from 2014 to 2017 is estimated to be 2,986,957 (CSA, 2013). Jimma is a relatively large town with nine legally operating wholesalers of pharmaceutical products which are currently supplying pharmaceutical products to retail pharmacies (n = 22), health centers (n = 4), clinics (n = 15) and hospitals (n = 2).
2.6.1. System suitability System suitability test was evaluated according to European Pharmacopoeia method (Ph. Eur., 2014b). The symmetry factor of principal peak of reference standard and percent relative standard deviation of replicate injections (6 times) of reference standard were calculated and compared against Pharmacopoeia specification limit i.e symmetry factor of the principal peak (0.8-1.5) and maximal permitted percent relative standard deviation (%RSD) of replicate injections (0.85).
2.2. Sample collection 2.6.2. Albendazole The amount of API of samples of ABZ tablets was investigated according to the United States Pharmacopoeia method (USP, 2015a).
From a total of 22 pharmacies officially operating in Jimma town, 10 pharmacies were selected using simple random sampling method. One box of anthelminthic was bought in each of retailing pharmacy resulting in samples for quality verification. One pharmacy did not have one of the requested anthelminthics. All samples were transported to Jimma University Laboratory of Drug Quality (JuLaDQ) on the same day of sample collection. In addition, survey on the sales volume and price of ABZ, MBZ and PZQ products available in legally operating wholesalers (n = 9) and retail pharmacies (n = 22) was conducted.
2.6.2.1. Preparation of standard solution. Approximately 100.0 mg of ABZ reference standard (RS) was accurately weighed into a 50.0 mL volumetric flask and dissolved in 5.0 mL of acidified methanol (sulfuric acid/methanol, 1/99% v/v). The prepared stock solution was diluted with methanol to volume and mixed. A volume of 5.0 mL of the solution was transferred into a second 50.0 mL volumetric flask and diluted with methanol to volume and mixed again.
2.3. Chemicals/reagents/solvents 2.6.2.2. Preparation of sample solution. Randomly selected tablets (n = 20) were finely powdered. A portion of powder equivalent to approximately 100.0 mg ABZ was transferred into a 50.0 mL volumetric flask, dissolved in 5.0 mL of acidified methanol (sulfuric acid/ methanol, 1/99% v/v), shaken for 15 min, diluted with methanol to volume, mixed and filtered with Whatman No. 1 filter paper by discarding the first 15.0 mL of the filtrate. A 5.0 mL of clear filtrate was transferred into a second 50.0 mL volumetric flask, diluted with methanol to volume and mixed.
ABZ (USP reference standard), MBZ (Janssen Pharmaceutica) and PZQ (Sigma-Aldrich) reference standards were used as received. Hydrochloric acid (37% w/v, Sigma-Aldrich), methanol (HPLC grade, Fishers Scientific), acetonitrile (HPLC grade, Fishers Scientific), orthophosphoric acid (Fluka Chemicals Ltd.), potassium phosphate monobasic (KH2PO4) (Sigma-Aldrich), ammonium phosphate monobasic (Sigma-Aldrich), sodium hydroxide (Sigma-Aldrich), sodium lauryl sulphate (Sigma-Aldrich) and ultra pure water (18.2 Ωcm) were used.
2.6.2.3. HPLC method. The samples were analyzed using HPLC equipped with a 254 nm UV–vis detector and a C18 column (4.6 mm x 25 cm, 5 μm) (Zorbax, Agilent). The mobile phase was a mixture of 0.50 g monobasic ammonium phosphate (NH4H2PO4) in 400.0 mL
2.4. Physical characteristics, packaging and labelling information Visual inspection of the physical characteristics of dosage form, packaging and labelling information was performed following the WHO 158
Acta Tropica 177 (2018) 157–163
S. Belew et al.
disintegration apparatus with disk (ERWEKA, GmbH, Germany). The test was performed for 15 min using a medium of 1000.0 mL de-ionized water at a temperature of 37 ± 0.5 °C and device’s basket raising and lowering frequency rate of 32 cycles/min.
water/methanol (40/60% v/v). The column temperature, injection volume and flow rate were 25 °C, 20.0 μL and 2.0 mL/min., respectively. 2.6.3. Mebendazole The amount of API was investigated according to the United States Pharmacopoeia method (USP, 2015b).
2.8. Dissolution 2.8.1. Albendazole The dissolution of tablet samples of each brand of ABZ was evaluated using a dissolution apparatus II (paddle) (Varian VK-7010 Dissolution apparatus, Agilent Technologies) following United States Pharmacopoeia test method for ABZ tablets (USP, 2015a). The test was performed for 45 min at a medium temperature and the spindle rotation speed of 37 ± 0.5 °C and 50 rpm, respectively. Six tablets, two from each brand of anthelminthics medicines were randomly assigned into the dissolution vessels containing a dissolution medium (900.0 mL 0.1 N HCl). A 10.0 mL samples was withdrawn at predetermined time points (15, 30, 45 min), immediately filtered using Whatman No. 1 filter paper and diluted in 250.0 mL volumetric flask with 0.1 N sodium hydroxide. The absorbance of each sample was determined at 308 and 350 nm using a UV/Visible spectrophotometer (Ultrospec-4000, Pharmacia Biotech) and the difference taken as absorbance value. A 0.1 N sodium hydroxide solution was used as the background. The quantity in milligram (mg) of dissolved ABZ was calculated by the formula 22.5 × C(Au/As), where C is the concentration of the ABZ reference standard (RS) in the standard solution (μg per mL) and Au and As are the absorbance differences, obtained at 308 and 350 nm, of the solution under test (Au) and the standard solution (As).
2.6.3.1. Preparation of standard solution. Approximately 25.0 mg of MBZ RS was transferred into a 100.0 mL volumetric flask and dissolved in 10.0 mL of formic acid and heated in a water bath at 50 °C for 15 min. The sample was mechanically shaken for 5.0 min, dissolved in 90.0 mL methanol and cooled. The solution was diluted to volume with methanol and mixed. A 5.0 mL of the solution was transferred to 25.0 mL volumetric flask, diluted with mobile phase to volume, mixed and filtered through a filter paper having a porosity of 0.5 μL. A 0.05 mg/mL of MBZ RS was prepared in mobile phase and used. 2.6.3.2. Preparation of sample solution. Randomly selected tablets (n = 20) were finely powdered. A portion of powder approximately equivalent to 500.0 mg MBZ was transferred into a 100.0 mL volumetric flask and dissolved in 50.0 mL of formic acid and heated in a water bath at 50 °C for 15 min. The flask was mechanically shaken for 1 h, diluted with water to volume, mixed and filtered with Whatman No. 1 filter paper. A 5.0 mL of the filtrate was transferred into a 100.0 mL volumetric flask and diluted with a solution of formic acid in methanol (formic acid/methanol, 1/9% v/v) to volume. Finally, 0.05 mg/mL of MBZ solution was prepared in mobile phase and used.
2.8.2. Mebendazole The dissolution of tablet samples of each brand of MBZ was evaluated using a dissolution apparatus II (paddle) (Varian VK-7010 Dissolution apparatus, Agilent Technologies) following United States Pharmacopoeia test method for MBZ tablets (USP, 2015b). The test was performed for 120 min at a medium temperature and the spindle rotation speed of 37 ± 0.5 °C and 75 rpm, respectively. Six tablets, two from each brand of anthelminthics medicines were randomly assigned into the dissolution vessels containing a dissolution medium (900.0 mL 0.1 N HCl containing 10 mg sodium lauryl sulphate per mL). A 10.0 mL samples was withdrawn at predetermined time points (30, 60, 90, 120 min) and immediately filtered using Whatman No. 1 filter paper. The samples were analyzed using HPLC equipped with 254 nm UV–vis detector and C-18 column (4.6 mm × 25 cm, 5 μ) (Microsorb Varian). The mobile phase used was mixture of acetonitrile (HPLC grade) and buffer solution (8.0 g of sodium hydroxide and 3.0 g of sodium lauryl sulphate in 2.0 L of water, pH of 2.5 adjust with phosphoric acid) (acetonitrile/buffer, 3/7% v/v). The column temperature, injection volume and flow rate were 25 °C, 10.0 μL and 1.0 mL/min, respectively.
2.6.3.3. HPLC method. The samples were analyzed using HPLC equipped with 247 nm UV–vis detector and a C18 column (4.6 mm × 25 cm, 5 μm) (Zorbax, Agilent). The mobile phase used was a mixture of 0.05 M monobasic potassium phosphate (KH2PO4) and methanol (0.05 M monobasic potassium phosphate/methanol, 40/60% v/v, pH = 5.5). The column temperature, injection volume and flow rate were 30 °C, 15.0 μL and 1.5 mL/min., respectively. 2.6.4. Praziquantel 2.6.4.1. Preparation of standard solution. The amount of API was investigated according to the United States Pharmacopoeia method (USP, 2015c). An accurately weighed amount of PZQ RS was dissolved in mobile phase (acetonitrile/water, 60/20% v/v) to obtain a solution having a concentration of about 0.18 mg/mL. 2.6.4.2. Preparation of sample solution. Randomly selected tablets (n = 20) were finely powdered. A portion of powder approximately equivalent to 150.0 mg PZQ was transferred into a 100.0 mL volumetric flask, dissolved in 70.0 mL mobile phase (acetonitrile/water, 60/40% v/v), sonicated for 5 min, diluted with mobile phase to volume, mixed and filtered with Whatman No. 1 filter paper. A volume of 3.0 mL of the filtrate was transferred into a 25.0 mL volumetric flask and diluted with mobile phase to volume and used.
2.9. Praziquantel The dissolution of tablet samples of each brand of PZQ was evaluated using a dissolution apparatus II (paddle) (Varian VK-7010 Dissolution apparatus, Agilent Technologies) following United States Pharmacopoeia test method for PZQ tablets (USP, 2015c). The test was performed for 75 min at a medium temperature and the spindle rotation speed of 37 ± 0.5 °C and 50 rpm, respectively. Six tablets, two from each brand of anthelminthics medicines were randomly assigned into the dissolution vessels containing a dissolution medium (900.0 mL 0.1 N HCl containing 2.0 mg of sodium lauryl sulphate per mL). A 10.0 mL samples was withdrawn at predetermined time points (15, 30, 60, 75 min) and immediately filtered using Whatman No. 1 filter paper. The amount of PZQ dissolved was determined at an absorbance wave length of 263 nm using a UV/Visible spectrophotometer (Ultrospec4000, Pharmacia Biotech).
2.6.4.3. HPLC method. The samples were analyzed using HPLC equipped with 210 nm UV–vis detector and a C18 column (4.6 mm x 25 cm, 5 μm) (Hypersil ODS, Thermo Scientific). The mobile phase used was a mixture of acetonitrile/water (60/40% v/v). The column temperature, injection volume and flow rate were 30 °C, 10.0 μL and 1.5 mL/min., respectively. 2.7. Disintegration The disintegration test was performed according to the European Pharmacopoeia (Ph. Eur., 2014c). Six tablets from each brand of ABZ, MBZ and PZQ were randomly selected and placed into tubes of the 159
Acta Tropica 177 (2018) 157–163
S. Belew et al.
3. Results
Table 2 Results of quantity of API of tablet samples (n = 20) of ABZ, MBZ and PZQ brands.
The survey results on weekly sales volume of anthelminthic medicines in legally operating wholesalers (n = 9) and retail pharmacies (n = 22) (S3 Table) revealed that the products of ABZ, MBZ and PZQ sampled for this study account for respectively 27, 60 and 100% of the products of each API of anthelminthic medicines available in Jimma. In addition, the weekly sales data of anthelminthic medicines in retail pharmacies in Jimma indicate that relatively large numbers of dosage units (n = 12,144) of the investigated products are dispensed per week. The price of the investigated products is presented in S4 Table. Considering the doses recommended by WHO, the average (n = 3) price per treatment of ABZ, MBZ and PZQ is 0.20, 0.45 and 0.40 USD, respectively. This shows that an average estimated minimum and maximum cost of the investigated anthelminthic medicines per treatment is 4.72 and 10.63 Ethiopian Birr (ETB), respectively.
% lable claim (%RSD, n = 2)a
Product Albendazole Albezole® 400 mg Ovis® 400 mg Wormin® 400 mg endazole Mebepharm® 100 mg Wormin® 100 mg Thelmox® 100 mg Praziquantel Bermoxel® 600 mg Distocide® 600 mg Praziquantel 600 mg a
97.74 (0.19) 96.88 (1.51) 95.05 (0.98) 102.53 (0.00) 108.24 (0.41) 110.09 (0.01) 99.46 (0.02) 96.83 (0.02) 102.12 (0.04)
number of injections.
Table 3 Disintegration time ranges of tablet samples (n = 6) of different brands of ABZ, MBZ and PZQ tablets.
3.1. Physical characteristics of tablets, packaging and labelling The results of visual inspection on physical characteristics, packaging and labelling information of samples of each brand of ABZ, MBZ and PZQ are presented in supplementary information table (S1 Table). The price of the investigated anthelminthic medicines is presented in supplementary information table (S4 Table). The results of visual inspection on physical characteristics of dosage form, packaging and labeling revealed that all samples did not show signs of counterfeit medicines defined by WHO.
Product name
API
Time range (min)
Albendazole Albezole® 400 mg Ovis® 400 mg Wormin® 400 mg
5.0–8.0 10.0–13.0 8.0–12.0 Mebendazole
Mebepharm® 100 mg Wormin® 100 mg Thelmox® 100 mg
3.2. Mass uniformity
1.0–1.5 1.0–1.1 3.0–4.0 Praziquantel
Bermoxel® 600 mg Distocide® 600 mg Praziquantel 600 mg
The mass uniformity results (Table 1) of tablet samples of each brand of ABZ, MBZ and PZQ were within the European Pharmacopoeia specification limit (i.e. no more than 2 individual masses > 5% of the average tablet weight and none deviating by more than 10% of the average tablet weight).
1.0–2.0 9.0–11.0 0.5–1.0
3.5. Dissolution The dissolution profile (mean ± SD, n = 6) of tablet brands of ABZ, MBZ and PZQ (Fig. 1A–C) revealed that two PZQ brands (i.e Bermoxel®, Q = 63.43 ± 0.70, Distocide®, Q = 62.43 ± 1.67) and one ABZ brand (i.e Wormin®, Q = 59.21 ± 0.99) failed to comply with the USP specification limits (i.e. ABZ: Q ≤ 80% at 30 min, MBZ: Q ≤ 75% at 120 min, PZQ: Q ≤ 75% at 60 min).
3.3. Amount of active pharmaceutical ingredient The assay results (Table 2) of API (mean ± SD% l.c.) showed that samples of all anthelminthic brands comply with the USP specification limit (90–110% l.c.). The percent relative standard deviation (%RSD) values (< 2%) of all samples indicated adequate analytical precision. 3.4. Disintegration
4. Discussion
The results of disintegration time (Table 3) of all product samples complied with the specification limits given in the European Pharmacopoeia (i.e complete disintegration of immediate release (IR) tablets ≤ 15 min).
Evaluating the quality of medicines circulating in the market is important to reduce risk of having poor quality medicines in the supply chain. In this study, we assessed the pharmaceutical quality of commonly available brands of ABZ, MBZ and PZQ tablets in Jimma town.
Table 1 Mass uniformity results of samples of different brands of ABZ, MBZ and PZQ tablets. Product Albendazole Albezole® 400 mg Wormin® 400 mg Ovis® 400 mg Mebendazole Mebepharm® 100 mg Wormin® 100 mg Thelmox® 100 mg Praziquantel Bermoxel® 600 mg Distocide® 600 mg Praziquantel 600 mg
Average tablet weight (mg) (n = 20)
Range of tablet weight (mg)
%RSD (n = 20)
LV – UV (mg)
1039.4 685.1 698.5
996.2–1078.1 670.4–696.2 679.7–729.3
0.12 0.07 0.11
987.4–1091.4 650.8–719.3 663. 6–733.4
262 302.6 315
248.7–270.6 289.5–308.6 313.9–318.1
0.11 0.1 0.01
248.9–275.1 287.4–317.7 299.3–330.8
734.7 910.1 747.9
721.4–742.2 884.1–929.8 737.7–767.9
0.03 0.07 0.05
697.9–771.4 864.6–955.6 710.5–785.5
%RSD: percent relative standard deviation; LV: lower limit; UV: upper limit.
160
Acta Tropica 177 (2018) 157–163
S. Belew et al.
Fig. 1. Dissolution profile (Mean ± SD, n = 6) of (A) ABZ tablet brands in 900 mL 0.1N HCl (37 ± 0.5 °C, rpm = 50), (B) MBZ tablet brands in 900 mL 0.1N HCl containing 1% sodium lauryl sulphate (37 ± 0.5 °C, rpm = 75) and (C) PZQ tablet brands in 900 mL 0.1N HCl containing 2.0 mg/mL sodium lauryl sulphate (37 ± 0.5 °C, rpm = 50) using a USP II apparatus.
RDZ® and Bendex® showed an egg reduction rate ranging between 91.9 and 98.7% against round worm (Ascaris lumbricoides), which is almost similar to the percent egg reduction rate observed for Zentel® (92.6%) and Ovis® (97.8%) (Albonico et al., 2007; Belew et al., 2015). This suggests that dissolution might not have an equally significant effect for roundworms as for hookworms. The differences in efficacy results observed against hookworm and roundworm might be attributed to the differences in feeding behaviour and/or routes of nutrient uptake between the two parasites (Gilbert, 1996; John et al., 2004; Skelly et al., 2014). This suggests that the in-vivo relevance of the in-vitro dissolution will depend on parasite type, with its life cycle, the medicine uptake mechanism and the internal parasite medicine pharmacology. Poor dissolution may thus not necessarily and automatically be linked to a reduced efficacy in all helminth parasitic species. Different mechanisms such as active efflux, reduced drug uptake, drug modification, drug sequestration, by-pass shunt of helminth parasites (Ouellette, 2001) should be taken into consideration for the in vitro-in vivo relationship (IVIVC). However, the concept of ‘substandard’ drugs, defined as ‘genuine medicines produced by the manufacturers authorized by the national medicines regulatory authority which do not meet quality specifications set for them by national standards’ (WHO, 2009) is not directly and automatically linked to IVIVC. Both aspects, i.e the regulatory standards based on quality consistency as well as the clinical relevance, are to be considered in the overall evaluation. Ideally, both aspects should be consistent; however, currently, due to the absence of well developed PK-PD models, there is not yet proof of this consistency, remaining a challenge for future research. Generally, since dissolution is a critical quality attribute, the poor dissolution of investigated medicines, could minimize the clinical efficacy and pose a challenge in chemotherapeutic approach which is one of the strategies that Ethiopia has been implementing to prevent, control and eliminate NTD by 2020 (FMoH, 2016). In addition, the poor quality of medicines could have a negative impact on some of the progress in Ethiopia that has been made in prevention, control and elimination of soil-transmitted helminths and schistosomiasis so far (Nebiyu et al., 2017). Moreover, poor quality of investigated anthelminthic medicines could increase the risk of drug resistance (Newton et al., 2010). Furthermore, since legally operating retail pharmacies in Jimma are dispensing relatively large numbers of dosage units (n = 12,144) of the investigated anthelminthic medicines per week, the poor dissolution of these medicines could have a negative impact on the recovery of a significant number of patients infected with STHs, schistosomiasis and other gastrointestinal worms.
The results of visual inspection of packaging and labelling information on the tested brands of ABZ, MBZ and PZQ tablets did not show signs of spurious, falsely labelled, falsified or counterfeit products as defined by WHO (WHO, 2009). This suggests that packaging and labeling information of each brand of anthelminthic medicines is in line with WHO guideline on packaging for pharmaceutical products (WHO, 2002). The results of mass uniformity of tablet samples of all anthelminthic medicines comply with pharmacopoeia specification limit (Ph. Eur., 2014a) (i.e. no more than 2 individual masses > 5% of the average tablet weight and none deviating by more than 2 × 5% of the average tablet weight). Though the mass uniformity results comply with pharmacopoeia specification limit, the presence of outlier tablets indicates inconsistency of tablet manufacturing process (Adeley et al., 2014). For a single dose preparation, variations in mass of tablets could influence uniformity of API and/or entire composition of a dosage unit. According to USP tablets of ABZ, MBZ and PZQ should contain the required amount of API (%l.c. = 90–110%) (USP, 2015a,b,c). The assay results of API (mean ± SD% l.c.) of all tablet samples of anthelminthic brands complied with the Pharmacopoeial specification limit. Thus, with respect to amount of API, interchangeable use of tablet brands containing the same API will most probably result in a similar clinical efficacy. Also, the assay results suggest that there is not a significant quality difference in the different tablet samples. The disintegration times complied with the pharmacopoeial specification limit (complete disintegration of IR tablets ≤ 15 min). However, 3–4 min disintegration time difference was observed in a set of samples of all ABZ tablet brands and one PZQ tablet brand (Distocide®). Moreover, Distocide® showed longer disintegration time (9–11 min) compared with the other praziquantel tablet brands (0.5–2 min). This might be attributed to variations in the manufacturing process and/or differences in the type and amount of excipient used (King Chiu et al., 1957). Considering the single point dissolution specification (mean ± SD, n = 6), one third of the tablet samples (one ABZ brand (Wormin®, Q = 59.21 ± 0.99) and two PZQ brands (Bermoxel®, Q = 63.43 ± 70 and Distocide®, Q = 62.43 ± 1.67)) failed to comply with the USP acceptance criteria (USP, 2015a,c) (i.e. ABZ: Q ≥ 80% at 30 min and PZQ: Q ≥ 75% at 60 min). For Biopharmaceutical Classification System (BCS) class II drugs like ABZ, MBZ and PZQ, dissolution is a rate limiting factor for absorption into the blood but assumed also into the parasite system (Takano et al., 2008). Thus, poor dissolution could be a risk of reduced efficacy. Indeed, it has been shown that ABZ tablet brands (Azol®, RDZ® and Bendex®) which failed to comply with the USP acceptance criteria for dissolution (Q ≥ 80 at 30 min) showed low percent egg reduction rate (i.e. RDZ®: 80.8%, Azol®: 73.1% and Bendex®: 88.7%) against hookworm (Ancylostoma duodenale or Necator americanus), while other brands (Zentel® and Ovis®) which did comply with the dissolution specification demonstrated relatively high percent egg reduction rate (i.e. Zentel®: 87.1% and Ovis®: 98.1%). On the other hand, having poor dissolution, Azol®,
5. Conclusion The results of the present study showed that all the samples of each brand of ABZ, MBZ and PZQ tablets complied with the pharmacopeial specification acceptance criteria for packaging and labeling information, mass uniformity, amount of API and disintegration. However, one 161
Acta Tropica 177 (2018) 157–163
S. Belew et al.
Substandard medicines in resource‐poor settings: a problem that can no longer be ignored. Trop. Med. Int. Health. Available at: http://onlinelibrary.wiley.com/doi/10. 1111/j.1365-3156.2008.02106.x/full. (Accessed 16 June 2017). Cohn, J., Schoen-Angerer, T.V., Jambert, E., Arreghini, G., Childs, M., 2012. When falsified medicines enter the supply chain: description of an incident in Kenya and lessons learned for rapid response. J. Public Health Policy 34, 22–30. http://dx.doi. org/10.1057/jphp.2012.53. Conteh, L., Thomas, E., Molyneux, D., 2010. Socioeconomic aspects of neglected tropical diseases. Lancet 375, 239–247. Central Statistical Agency (CSA). Federal Democratic Republic of Ethiopia. Federal Democratic Republic of Ethiopia Central Statistical Agency population projection of Ethiopia for all regions at wereda level from 2014-2017, 2013. Available at: www. csa.gov.et/index.php/ehioinfo-internal?download=724:population. (Accessed: 16/ 06/2016). Dana, D., Mekonnen, Z., Emana, D., Ayana, M., Getachew, M., Workneh, N., Vercruysse, J., Levecke, B., 2014. Prevalence and intensity of soil-transmitted helminth infections among pre-school age children in 12 kindergartens in Jimma town, southwest Ethiopia. Trans. R. Soc. Trop. Med. Hyg. 109, 225–227. http://dx.doi.org/10.1093/ trstmh/tru178. Federal Ministry of Health (FMoH), 2016. The second edition of Neglected Tropical Diseases Master Plan 2015/2016. Federal democratic republic of Ethiopia, Addis Ababa. Available at: https://www.medbox.org/national-neglected-tropical-diseasesmaster/download.pdf. (Accessed 03 September 2017). Fadeyi, I., Kaur, H., Lalani, M., Mailk, N., Wyk, A.V., 2015. Quality of the antibiotics—amoxicillin and co-trimoxazole from Ghana, Nigeria, and the United Kingdom. Am. J. Trop. Med. Hyg. 92 (6 Suppl), 87–94. http://dx.doi.org/10.4269/ ajtmh.14-0539. Gilbert, A.C., 1996. Medical microbiology 4th edition. Helminths: Structure, Classification, Growth, and Development Available at: www. ncbi. nlm. nih. gov/ books/NBK8282 (Accessed 15 June 2017). Giralt, A.N., Schiavetti, B., Meessen, B., Pouget, C., Caudron, J.M., Marchal, B., Massat, P., Thys, S., Ravinetto, R., 2017. Quality assurance of medicines supplied to low-income and middle-income countries: poor products in shiny boxes? BMJ Glob. Health 2 (2). http://dx.doi.org/10.1136/bmjgh-2016-000172. John, P.D., Patrick, S., David, W.H., 2004. Role of tegument and gut in nutrient uptake by parasitic platyhelminths. Can. J. Zool. 82, 211–232. King Chiu, K., Fred, O.S., Albert, M.M., 1957. Factors affecting tablet disintegration. J. Pharm. Sci. 46, 236–239. Lacey, E., 1990. Mode of action of benzimidazoles. Parasitol. Today 6, 112–115. http:// dx.doi.org/10.1016/0169-4758(90)90227-u. Leslie, T., Kaur, H., Mohammed, N., Kolaczinski, K., Ord, R.L., Rowland, M., 2009. Epidemic of Plasmodium falciparum malaria involving substandard antimalarial drugs, Pakistan, 2003. Emerg. Infect. Dis. 15, 1753–1759. http://dx.doi.org/10. 3201/eid1511.090886. Mekonnen, Z., Suleman, S., Biruksew, A., Tefera, T., Chelkeba, L., 2016. Intestinal polyparasitism with special emphasis to soil-transmitted helminths among residents around Gilgel Gibe Dam, southwest Ethiopia: a community based survey. BMC Public Health 16, 1185. Mengistu, M., Shimelis, T., Torben, W., Terefe, A., Kassa, T., Hailu, A., 2011. Human intestinal schistosomiasis in communities living near three rivers of Jimma town, south western Ethiopia. Ethiop. J. Health Sci. 21. http://dx.doi.org/10.4314/ejhs. v21i2.69051. Nebiyu, N., Birhan, M., Biruck, K., Kebede, D., Ephrem, E., Gemechu, T., Kalkidan, M., Mesfin, S., 2017. Ethiopia schistosomiasis and soil-transmitted helminthes control programme: progress and prospects. Ethiop. Med. J. 55 (Suppl. 1). Newton, P.N., Michael, D.G., Facundo, M.F., 2010. Impact of poor-quality medicines in the ‘developing’ world. Trends Pharmacol. Sci. 31, 99–101. http://dx.doi.org/10. 1016/j.tips.2009.11.005. Ouellette, M., 2001. Biochemical and molecular mechanisms of drug resistance in parasite. Trop. Med. Int. Health 6, 874–882. Peyraud, N., Rafael, F., Parker, L.A., Quere, M., Alcoba, G., Korff, C., Gabriel, A., Christian, K., Michael, D., Pernette, B.E., Jean-Clément, C., Micaela, S., Iza, C., Monica, R., Islam Amine, L., Frédéric, B., Francesco, G., Benoit, K.I., Jean-Claude, A., Newton, P.N., 2017. An epidemic of dystonic reactions in central Africa. Lancet Glob. Health 5 (2). http://dx.doi.org/10.1016/s2214-109x(16)30287-x. European Pharmacopoeia (Ph. Eur.), 2014a. Uniformity of Mass of Single Dose Preparations, 8th ed. European Directorate for Quality of Medicines and Health care, Strasbourg, France, pp. 297–298. European Pharmacopoeia (Ph. Eur.), 2014b. 2.2.46. Chromatographic Separation Techniques, 8th ed. European Directorate for Quality of Medicines and Health care, Strasbourg, France, pp. 72–79. European Pharmacopoeia (Ph. Eur.), 2014c. Disintegration of Tablets and Capsules, 8th ed. European Directorate for Quality of Medicines and Health care, Strasbourg, France, pp. 225–227. Skelly, P.J., Dadara, A.A., Li, X., Castro-Borges, W., Wilson, R.A., 2014. Schistosome feeding and regurgitation. PLoS Pathog. 10. http://dx.doi.org/10.1371/journal.ppat. 1004246. Suleman, S., Zeleke, G., Deti, H., Mekonnen, Z., Duchateau, L., Levecke, B., Jozef, V., D'Hondt, M., Evelien, W., Spiegeleer, B.D., 2014. Quality of medicines commonly used in the treatment of soil transmitted helminths and giardia in Ethiopia: a nationwide survey. PLoS Negl. Trop. Dis. 8. http://dx.doi.org/10.1371/journal.pntd. 0003345. Suleman, S., Woliyi, A., Woldemichael, K., Tushune, K., Duchateau, L., Degroote, A., Roy, V., Nathalie, B., De Spiegeleer, B., 2016. Pharmaceutical regulatory framework in Ethiopia: a critical evaluation of its legal basis and implementation. Ethiop. J. Health Sci. 26, 259. http://dx.doi.org/10.4314/ejhs.v26i3.9.
third of samples failed to comply with the pharmacopoeial specification limit set for dissolution test. In general, the results of this study suggest that anthelminthic medicines circulating in the market could have risk of reduced efficacy. Therefore, poor quality of medicines could influence the chemotherapeutic intervention approach in reducing morbidity caused by soil-transmitted helminths and schistosomiasis. Thus, continuous monitoring, in a systematic way, the quality of anthelminthic medicines circulating in the market is recommended. Conflict of interest Authors declare no conflict of interest. Authors’ contribution Conceived and designed the experiments: BDS MD EW LD SS SB. Performed the experiments: SB, SS, MD, EW. Analyzed the data: BDS, LD, SB, EW, AK. Contributed reagents/materials/analysis tools: BDS, MD, LD, SS. Wrote the paper: BDS, MD, EW, LD, SS, SB, AK. Funding BOF (Special Research Fund) is funding a PhD scholarship of Sileshi Belew in Gent University (Scholarship code 01W03714, Reference number DOZA/ILDDC/AM/0866b-2014). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Acknowledgement The authors would like to thank Laboratory of Drug Quality and Registration (DruQaR), Gent University, Belgium for the provision of the reference substances. Additionally, we would like to thank the staff of the Laboratory of Drug Quality of Jimma University (JuLaDQ) (Markos Duguma, Henok Teshome, Tesfaye Mohammed and Yimer Mekonnen) for their kind support and collaboration. Appendix A. Supplementary data Supplementary data associated with this article can be found, in the online version, at http://dx.doi.org/10.1016/j.actatropica.2017.10. 006. References Adeleye, O.A., Femi-Oyewo, M.N., Odeniyi, M.A., 2014. The effect of processing variables on the mechanical and release properties of tramadol matrix tablets incorporating cissus populnea gum as controlled release excipient. Polim. Med. 44, 209–220. Albonico, M., Mathema, P., Montresor, A., Khakurel, B., Reggi, V., Pandey, S., Savioli, L., 2007. Comparative study of the quality and efficacy of originator and generic albendazole for mass treatment of soil-transmitted nematode infections in Nepal. Trans. R. Soc. Trop. Med. Hyg. 101, 454–460. http://dx.doi.org/10.1016/j.trstmh.2006.09. 003. Bajiro, M., Dana, D., Ayana, M., Emana, D., Mekonnen, Z., Zawdie, B., Asfaw, G., Ashenafi, K., Zeynudin, A., 2016. Prevalence of Schistosoma mansoni infection and the therapeutic efficacy of praziquantel among school children in Manna district, Jimma zone, southwest Ethiopia. Parasit. Vectors 9, 560. http://dx.doi.org/10.1186/ s13071-016-1833-6. Belew, S., Getachew, M., Suleman, S., Mohammed, T., Deti, H., Dhondt, M., Wynendaele, E., Mekonnen, Z., Vercruysse, J., Duchateau, L., De Spiegeleer, B., Levecke, B., 2015. Assessment of efficacy and quality of two albendazole brands commonly used against soil-transmitted helminth infections in school children in Jimma town, Ethiopia. PLoS Negl. Trop. Dis. 9 (9). http://dx.doi.org/10.1371/journal.pntd.0004057. Bereket, A., Zewdneh, T., 2015. Schistosoma mansoni Schistosoma mansoni infection prevalence and associated risk factors among schoolchildren in Demba Girara, Damot Woide District of Wolaita Zone, southern Ethiopia. Asian Pac. J. Trop. Med. 8, 457–463. Bitew, A.A., Abera, B., Seyoum, W., Endale, B., Kiber, T., Goshu, G., Admass, A., 2016. Soil-transmitted helminths and Schistosoma mansoni infections in Ethiopian Orthodox Church students around lake tana, northwest Ethiopia. PLoS One 11 (5). http://dx.doi.org/10.1371/journal.pone.0155915. Caudron, J., Ford, N., Henkens, M., Mace, C., Kiddle-Monroe, R., Pinel, J., 2008.
162
Acta Tropica 177 (2018) 157–163
S. Belew et al.
United States Pharmacopoeia, 2015c. USP 38/NF 33. USP Monographs: Praziquantel Tablets. The United States Pharmacopoeial Convention, 12601 Twinbrook Parkway, Rockville, MD, USA pp. 4969. World Health Organization (WHO), 2002. Technical Report Series No 902. Annex 9 Guideline on Packaging for Pharmaceutical Products. Thirty-sixth Report. World Health Organization, Geneva. Available at: http://apps.who.int/medicinedocs/en/d/ Jh3009e/. (Accessed 14 June 2017). World Health Organization (WHO), 2009. Counterfeit Medicines: Frequently Asked Questions. Available at http://www.who.int/medicines/services/counterfeit/faqs/ QACounterfeit-October2009.pdf. (Accessed 12 March 2015). World Health Organization (WHO), 2010. First WHO report on Neglected Tropical Diseases: working to overcome the global impact of neglected tropical diseases. . Available at: http://apps.who.int/iris/bitstream/10665/44440/1/9789241564090_ eng.pdf. (Accessed 16/06/2017). World Health Organization (WHO), 2015. Tool for Visual Inspection of Medicines. A Checklist for Visual Inspection of Medicines in Order to Identify Suspicious Products for Further Examination. Available at: http://www.whpa.org/toolkit_beaware_ inspection.pdf. (Accessed 16 February 2015).
Tadege, B., Shimelis, T., 2017. Infections with Schistosoma mansoni and geohelminths among school children dwelling along the shore of the Lake Hawassa, southern Ethiopia. PLoS One 12 (7), e0181547. http://dx.doi.org/10.1371/journal.pone. 0181547. Takano, R., Furumoto, K., Shiraki, K., Takata, N., Hayashi, Y., Aso, Y., Yamashita, S., 2008. Rate-limiting steps of oral absorption for poorly water-soluble drugs in dogs; prediction from a mini scale dissolution test and a physiologically-based computer simulation. Pharm. Res. 25, 2334–2344. http://dx.doi.org/10.1007/s11095-0089637-9. Tefera, E., Belay, T., Mekonnen, S.K., Zeynudin, A., Belachew, T., 2017. Prevalence and intensity of soil-transmitted helminths among school children of Mendera elementary school, Jimma, southwest Ethiopia. Pan Afr. Med. J. 27, 88. http://dx.doi.org/10. 11604/pamj. United States Pharmacopoeia, 2015a. USP 38/NF 33. USP Monograph: Albendazole Tablets. The United States Pharmacopoeial Convention, 12601 Twinbrook Parkway, Rockville, MD, USA pp. 2067. United States Pharmacopoeia, 2015b. USP 38/NF 33. USP Monographs: Mebendazole Tablets. The United States Pharmacopoeial Convention, 12601 Twinbrook Parkway, Rockville, MD, USA pp. 4210.
163