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Factors affecting formation of microemulsions containing modified coconut oil
Accepted Manuscript Title: Factors affecting formation of microemulsions containing modified coconut oil Author: Sirikarn Pengon, Chutima Limmatvapirat, Sontaya Limmatvapirat PII: DOI: Reference:
S1818-0876(15)00170-1 http://dx.doi.org/doi: 10.1016/j.ajps.2015.11.007 AJPS 232
To appear in:
Asian Journal of Pharmaceutical Sciences
Please cite this article as: Sirikarn Pengon, Chutima Limmatvapirat, Sontaya Limmatvapirat, Factors affecting formation of microemulsions containing modified coconut oil, Asian Journal of Pharmaceutical Sciences (2015), http://dx.doi.org/doi: 10.1016/j.ajps.2015.11.007. This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Factors affecting formation of microemulsions containing modified coconut oil Sirikarn Pengona,b,c,*, Chutima Limmatvapiratd, Sontaya Limmatvapiratb,c a
Faculty of Pharmacy, Siam University, Bangkok 10160, Thailand.
b
Department of Pharmaceutical Technology, Faculty of Pharmacy, Silpakorn University, Nakhon
Pathom 73000, Thailand. c
Pharmaceutical Biopolymer Group (PBiG), Faculty of Pharmacy, Silpakorn University, Nakhon
Pathom 73000, Thailand d
Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Silpakorn University, Nakhon
Pathom 73000, Thailand. *E-mail: [email protected] Modified coconut oil (MCO) is the product derived from glycerolysis process of coconut oil. It contains monolaurin and lauric acidthat have been reported as antimicrobial agents against various bacteria and fungi [1, 2]. However, the MCO showed hydrophobicity, less biocompatible and therefore need to be developed into suitable dosage forms. Microemulsions are one of pharmaceutical preparations that could load a variety of chemical compounds including oils and might be a suitable dosage form for MCO. However, there is no study exploring the possibility of microemulsions as the carrier for MCO loading. In this study, the factors affecting formation of MCO microemulsions were investigated. To prepare microemulsions containing MCO, MCO was firstly prepared by glycerolysis process. The coconut oil and glycerol were separately heated at 200C and then vigorously mixed for 30 minutes. The mixture was immediately neutralized with hydrochloric acid and washed with distilled water to obtain the MCO. MCO microemulsions were prepared by titration method [3]. The effect of MCO: aqueous solution of Cremophor RH40: ethanol on properties of microemulsions was investigated. Particle size and antimicrobial properties were investigated by particle sizer and disc diffusion method, respectively. The results are shown in Fig. 1. According to the pseudo-ternary phase diagram, the MCO was existed in the clear microemulsions with high percentage of ethanol (more than 30%v/v). The lowest amount of MCO that could incorporate into microemulsions was 5% v/v. The droplet size of 5% v/v MCO microemulsions was decreased as increasing concentration of ethanol from 30-50 %v/v. The droplet sizes of microemulsions containing ethanol from 35 to 50% v/v were in the range of 1.0 to 12 nm. All MCO microemulsions containing 5% v/v can kill gram-positive bacteria (S. epidermidis and S. aureus) and gram-negative bacteria (E. coli, S. enterica LT2 and P. aeruginosa). Therefore, the more water compatible form of antimicrobial MCO microemulsions was successfully achieved in this study.
Page 1 of 3
Keywords: Coconut oil; Monolaurin; Antimicrobial
Acknowledgements This work was supported by the Thailand Research Fund; the Commission on Higher Education; the Royal Golden Jubilee Ph.D. Program (PHD/0343/2551); the Thailand Toray Science Foundation; the Silpakorn University Research and Development Institute; Faculty of Pharmacy, Silpakorn University and Faculty of Pharmacy, Siam University.
References [1] Bergsson G, Arnfinnsson J, Steingrimsson O, et al. Killing of Gram-positive cocci by fatty acids and monoglycerides. APMIS 2001;109(10):670-8. [2] Altieri C, Bevilacqua A, Cardillo D, et al. Antifungal activity of fatty acids and their monoglycerides against Fusarium spp. in a laboratory medium. Int J Food Sci Tech. 2009;44(2):242-5. [3] Tandel H, Raval K, Nayani A, et al. Preparation and evaluation of cilnidipine microemulsion. J Pharm Bioall Sci 2012;4(Suppl 1):S114-S5.
Page 2 of 3
(A)
(B)
Fig. 1 Particle size (A) and antimicrobial properties (B).
Page 3 of 3
S1818-0876(15)00170-1 http://dx.doi.org/doi: 10.1016/j.ajps.2015.11.007 AJPS 232
To appear in:
Asian Journal of Pharmaceutical Sciences
Please cite this article as: Sirikarn Pengon, Chutima Limmatvapirat, Sontaya Limmatvapirat, Factors affecting formation of microemulsions containing modified coconut oil, Asian Journal of Pharmaceutical Sciences (2015), http://dx.doi.org/doi: 10.1016/j.ajps.2015.11.007. This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Factors affecting formation of microemulsions containing modified coconut oil Sirikarn Pengona,b,c,*, Chutima Limmatvapiratd, Sontaya Limmatvapiratb,c a
Faculty of Pharmacy, Siam University, Bangkok 10160, Thailand.
b
Department of Pharmaceutical Technology, Faculty of Pharmacy, Silpakorn University, Nakhon
Pathom 73000, Thailand. c
Pharmaceutical Biopolymer Group (PBiG), Faculty of Pharmacy, Silpakorn University, Nakhon
Pathom 73000, Thailand d
Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Silpakorn University, Nakhon
Pathom 73000, Thailand. *E-mail: [email protected] Modified coconut oil (MCO) is the product derived from glycerolysis process of coconut oil. It contains monolaurin and lauric acidthat have been reported as antimicrobial agents against various bacteria and fungi [1, 2]. However, the MCO showed hydrophobicity, less biocompatible and therefore need to be developed into suitable dosage forms. Microemulsions are one of pharmaceutical preparations that could load a variety of chemical compounds including oils and might be a suitable dosage form for MCO. However, there is no study exploring the possibility of microemulsions as the carrier for MCO loading. In this study, the factors affecting formation of MCO microemulsions were investigated. To prepare microemulsions containing MCO, MCO was firstly prepared by glycerolysis process. The coconut oil and glycerol were separately heated at 200C and then vigorously mixed for 30 minutes. The mixture was immediately neutralized with hydrochloric acid and washed with distilled water to obtain the MCO. MCO microemulsions were prepared by titration method [3]. The effect of MCO: aqueous solution of Cremophor RH40: ethanol on properties of microemulsions was investigated. Particle size and antimicrobial properties were investigated by particle sizer and disc diffusion method, respectively. The results are shown in Fig. 1. According to the pseudo-ternary phase diagram, the MCO was existed in the clear microemulsions with high percentage of ethanol (more than 30%v/v). The lowest amount of MCO that could incorporate into microemulsions was 5% v/v. The droplet size of 5% v/v MCO microemulsions was decreased as increasing concentration of ethanol from 30-50 %v/v. The droplet sizes of microemulsions containing ethanol from 35 to 50% v/v were in the range of 1.0 to 12 nm. All MCO microemulsions containing 5% v/v can kill gram-positive bacteria (S. epidermidis and S. aureus) and gram-negative bacteria (E. coli, S. enterica LT2 and P. aeruginosa). Therefore, the more water compatible form of antimicrobial MCO microemulsions was successfully achieved in this study.
Page 1 of 3
Keywords: Coconut oil; Monolaurin; Antimicrobial
Acknowledgements This work was supported by the Thailand Research Fund; the Commission on Higher Education; the Royal Golden Jubilee Ph.D. Program (PHD/0343/2551); the Thailand Toray Science Foundation; the Silpakorn University Research and Development Institute; Faculty of Pharmacy, Silpakorn University and Faculty of Pharmacy, Siam University.
References [1] Bergsson G, Arnfinnsson J, Steingrimsson O, et al. Killing of Gram-positive cocci by fatty acids and monoglycerides. APMIS 2001;109(10):670-8. [2] Altieri C, Bevilacqua A, Cardillo D, et al. Antifungal activity of fatty acids and their monoglycerides against Fusarium spp. in a laboratory medium. Int J Food Sci Tech. 2009;44(2):242-5. [3] Tandel H, Raval K, Nayani A, et al. Preparation and evaluation of cilnidipine microemulsion. J Pharm Bioall Sci 2012;4(Suppl 1):S114-S5.
Page 2 of 3
(A)
(B)
Fig. 1 Particle size (A) and antimicrobial properties (B).
Page 3 of 3