Experimental Oral Cholecystography with a New Contrast Medium, Teridax (Triiodoethionic Acid)*

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carbonate in an evaporating dish and heated with stirring until the odor of the 3.5-dibromo-4-fluorobenzoyl chloride was no longer discernible. The mixture was then stirred with distilled water and the undissolved portion collected on a Biichner funnel. The 3,Fi-dibronio-.i-fluoroben7.ariiitle was recrystallized from ethyl alcohol. The yicld was 1.5 Gm., m. 207.5-208”. And-Calcd. for C7HIONBr2F: N, 4.717. Found: N, 4.72. Test for Opacity of 3,5-Dibromo-4-fluorobenzoic Acid, 3,5-Dibromo-4-fluorohippuric Acid and Ethyl 3,5-Dibromo-4-fluorobenzoate.-Solutions or suspensions of these in peanut oil were compared with the opaque properties of a n aqueous solution of tetraiodophenolphthalein. The latter solution was made to contain 100 mg. of iodine per cubic centimeter and the others contained an equimolecular quantity of bromine. One-half cubic centimeter portions of the opaque solutions or suspensions were placed in the stomach and peritoneum of anesthetized mice and radiographed. Results of the tests revealed that the bromo-fluoro compounds gave better radiographs of the stomach than the iodo compound.

Vol. XLII, No. 8

REFERENCES 1 ) Greerie. A. 8..X-Ray Trrhniciaa. 9 , 231 1988). (2) Graham. E. A.. Cole, W. H..and Copher. G . H.. .I. A m . M s d . Assoc.. 84, 14(1925). “h‘ew and Non-Official Remedies- -1951 Amrrican Medical Association. Chicago. 111.. 19.51, pp. %8&281 (4) Greenhaum. 1’. R., and Peters, A. I’.. Riir/iolo#y. 35, l5(I!l40) ( 5 ) Hull. A. W.. ;uid Rice. h l . . Phy.t. R m . , 8 , :i%G(l!Il(i). (fi)Binz. A.. Rath. C.. hlaier-Rode, H.. and Herman, K , rlagew. Chein.. 45, 713(1932). (7) Henne, A. la., and Midgley. T.,.I. .‘tin. Chcm. Sor.. 58, 882(1936). (8) Mittelstaedt. S. G., and Jenkins. G. L.. THIS JOURNAL. 39. 4(1950). (9) Schiemann. G.. and Winkelmuller. W.. in Blatt. A. H.. “Organic Syntheses.” Coll. Vol 2, John Wilev & Sons, New York. 1943. p. 299. (10) F k i n b o t t o m , W. J . . “Reactions of Organic Compounds, 2nd ed., Longmans. Green and Co., New York. 1948, p. 323. (11). Cason. I.. and Rapoport. H . . “Laboratory Text in Organic Chemistry,’’ Prentice-Hall, New York, 1950, p. 170. (12) Adkins. H.. and Mc1Slv:iin. S. M.. “Practice of Organic Chemistry.” 1st ed.. h4rGraw-Hil1, New York, 1925. p. 221 (13) Gattermann. I... and Wieland, H.. “Laboratory Methods of Organic Chemistry,” 22nd ed., hlacmillan and Co., London. 1932, p. 110. (14) Ingersoll. A. W..and Babcock. S. H., in Blatt. A. H., “Organic Syntheses.” Coll. Vol. 2. John Wiley & Sons, New York, 1943, p. 328. (15) Cattermann, I,.. and Wieland, H., “Laboratory Methods of Organic Chemistry,” 22nd ed.. Macmillan and Co.. London, 1932, p. 119

.“

Experimental Oral Cholecystography with a New Contrast Medium, Teridax (Triiodoethionic Acid) * By S. MARGOLIN, I. R. STEPHENS, M. T. SPOERLEIN, A. MAKOVSKY, and G. B. BELLOFF Teridax (triiodoethionic acid), a new, oral cholecystographic medium was evaluated in non-anesthetized, trained dogs. At 100 mg./Kg., Teridax visualized the gall bladder more distinctly than 300 mg./Kg. iodoalphionic acid. The new compound at 1 5 0 mg./K was as effective as 300 mg./Kg. of iodopanoic acid. Maximal opacity occurref between eight and ten hours with both Teridax and iodoalphicmic acid. The safety of Teridax is indicated by acute toxicity data obtained in mice, rats,. guinea pigs, and dogs. Blood determinations showed normal total and differential white blood cell counts, red blood cell counts, blood sugars, and hemoglobin values in all animals. Gross and microscopic examination showed no pathological changes in any organs examined. Liver and kidney function tests in dogs chronically medicated with Teridax were normal. No emetic reactions occurred in dogs, nor was there any evidence of gastric irritation. Pharmacodynamic tests with anesthetized dogs have not shown any deleterious effects upon respiration o r the cardiovascular system. Clinical data indicate a close parallel between the gall-bladder o acity and definition, absence of colon opacity or gasuointestinal irritation, and tge safety of Teridax in laboratory animals and in man.

.

agents have attained wide clinical acceptance in the routine diagnosis of gall-bladder disease. For t h e past decade, Priodax (iodoalphionic acid), has been the standard cholecystographic contrast medium. Compared to tetraiodophenolphthalein, iodoalphionic acid produces fewer undesirable side effects, and serious toxicity is rare. RAL CHOLECYSTOGFUPHIC

0

*Received January 28, 1953, from t h e Pharmacology Laboratories, Schering Corp., Bloomfield, N. J.

Nevertheless, the occurrence of these side actions continued to be objectionable and prompted continued synthetic programs directed toward more satisfactory substances. I n our laboratories, experimental studies (1) were directed toward finding a compound which would provide : (a) freedom from nausea, diarrhea, dysuria, emesis, irritation of mucous membranes; low systemic toxicity; (b) clearly defined shadow, b u t one which would not be so dense as to obscure

EDITION SCIENTIFIC

August, 1953

the presence of stones; (c) visualization of the gall bladder without causing interfering shadows in the colon. Preliminary laboratory findings with Teridax [alpha-ethyl beta - (2,4,6,- triiodo - 3 - hydroxy phenyl) propionic acid], suggested that this rompound might possess the properties outlined above. In further experimental comparisons, Teridax produced gall-bladder shadows superior t o those obtainable with either iodoalphionic acid, or Telepaque (iodopanoic acid), as evidenced by roentgenogram density and definition. Outstanding was t h e absence of emesis or retching with Teridax in the several dogs tested, whereas iodoalphionic acid and iodopanoic acid elicited these undesirable reactions in the same dogs. Teridax has low systemic toxicity, and a therapeutic index in animals comparable t o that of iodoalphionic acid.

EXPERIMENTAL

2 1

0

477 Fair: A faint shadow of the gall bladder with faint, but visible definition. Poor: Faint evidence of gall-bladder concentration as shown by an area of increased density in the region of the gall bladder, but with no definition. Failure: hTo visualization whatsoever.

The following information was recorded: (a) hourly scores of gall-bladder visualization, ( b ) earliest maximal visualization, ( c ) presence of contrast agent in the large bowel, ( d ) occurrence of retching and/or vomiting. The average maximal visualization obtained with the various compounds is summarized in Table I. Teridax at 150 mg./Kg. produced an opacity and definition equal t o that obtained with 300 mg./Kg. of iodopanoic acid. At 100 mg./Kg., Teridax was distinctly superior t o 300 mg./Kg. of iodoalphionic acid.

TABLE I . ~ R ACROLECYSTOGRAPHIC L STIJDIJIS IN DOGS

Oral Cholecystography in Dogs.-Experimental evidence suggests that the dog is the most suitable laboratory animal for the study of new cholecystographic compounds (3-5). Dogs weighing 7-11 Kg. were kept in the laboratory over several months, so that the same animals could be employed in a comparative series of tests with the various dosages of contrast media. In the experiments reported below, each of five dogs received comparable dosage regimens of the three substances used (Table I). The animals were trained to maintain their position under the roentgen tube; no anesthetic was required. The animals were fasted during the experiments except when visualization persisted for more than twenty-four hours. On such occasions, dogs were fed one pint of lowfat milk at twenty-eight hours after the oral administration of the compound, but were not fed solid food until after the forty-eight-hour picture. For all dogs, at least two weeks elapsed between each cholecystographic series. The compounds were given orally in gelatin capsules. Roentgenograms were taken hourly for ten hours, after the administration of the contrast agent. Additional exposures were made at twentyfour hours, and at irregular intervals thereafter until a gall-bladder shadow no longer appeared. An Animagraph X-ray unit was employed with instrument settings at 80-88 R V P and 15 ma., and exposures of one-thud second. Films were processed under standard conditions. Scorings of cholecystograms according to the method of Hoppe ( 2 ) were made by two or three observers to evaluate gall-bladder opacity and definition: 4

3

INDEX CHOLECYSTROCRAPHIC Excellent: A sharp outline of the gall bladder with sufficient intensity t o make the gall bladder stand out in brilliant contrast with the surrounding tissues. Good: A distinct shadow of the gall bladder with satisfactory intensity and good definition.

e

DO-

Compound

Triiodoethionic acid (Teridax)

Mg./&.

Average Number Cholec sto of grapiic Dogs Index

300 150 100

5 5 3

3.2 3.6 3.5

75

2

2.0

The maximal gall-bladder opacity and definition with Teridax and iodoalphionic acid occurred a t eight t o ten hours. However, iodopanoic acid attained maximal visualization a t approximately seven hours. To a varying degree, the large bowel was visualized by these agents. Colon shadows were least with Teridax and iodoalphionic acid; greatest with iodopanoic acid. A t 300 mg./Kg.. iodoalphionic acid appeared in the colon after the maximal visualization in three of five dogs, at the same time in one, and before in the fifth. In two of three dogs studied, Teridax at 300 tng./Kg. appeared in the colon after the gall bladder was visualized t o a maximal degree; in the third dog, the contrast medium appeared concomitantly in the colon and the gall bladder. At 150 mg./Kg., Teridax, in two of four dogs, appeared in the colon after the earliest maximal visualization of the gall bladder; in the third dog, at the same time. I n the fourth dog, a dense spot (apparently an unabsorbed tablet fragment) was noted in the colon just prior t o visualization of the gall bladder. With iodopanoic acid a t 300 mg./Kg., opacity of the colon occurred before maximal visualization of the gall bladder in two of four dogs; at the same time in the remaining two. In no instance did Teridax or iodoalphionic acid opacify the large bowel before maximal visualization of the gall bladder. Acute Toxicity in Rodents.-The acute toxicity for Teridax was determined in Manor mice, SpragueDawley rats, and Manor guinea pigs. The median

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TABLE II.-AcuTE Substance

Triiodoethionic

Species

Mouse Rat

Iodoalphionic

Guinea pig Mouse Rat Guinea pig

P

Vol. XLII, No. 8

TOXICITY OF TERIDAX IN RODENTS Mode of Administration

Number of Animals

Oral Intraperitoneal Oral Intraperitoneal Intraperitoneal Oral Intraperitoneal Intraperitoneal In traperitoneal

LDu and Confidence Limits.' Gm./Kg.

1.8W (1.640to 2.090) 0.440 (0.400to 0.485) Greater than 5.0 0.648(0.528to 0.794) 0.570 (0.525 to 0.619) 2.950 (2.618to 3.320) 0.640 (0.576 to 0.710) 0.510(0.430to 0.605) 0.930(0.820to 1.065)

47 60 18 27 29 42 64 50 42

= 0.05.

lethal dose (LDbo) and confidence limits, computed by the method of Litchfield and Wilcoxon (6). are summarized in Table 11. In toxic doses, Teridax or iodoalphionic acid caused sedation, generalized central nervous system depression, followed by intermittent colonic convulsions and dyspnea. The immediate cause of death was respiratory failure.

Intravenous Infusion Toxicity in Dogs.Six mongrel dogs weighing 6.0to 15.8 Kg. were anesthetized with morphine sulfate subcutaneously, plus sodium pentobarbital intravenously (Table 111). An additional four dogs weighing 9.0 to 12.0 Kg. were anesthetized with chloral hydrate, intravenously. Blood pressure was recorded manometrically by cannulation of the right carotid artery. The com-

pound was dissolved in water and dilute NaOH. brought to PH 7.5 with dilute HCl, and infused into the right femoral vein. Pulse and respiration rates were taken a t intervals throughout the experiment. The average intravenous lethal dose for Teridax in dogs anesthetized with morphine-sodium pentobarbital was 481.7mg./Kg.; and in dogs anesthetized with chloral hydrate, 203.4 mg./Kg. Teridax was significantly more toxic to dogs anesthetized with chloral hydrate than to those anesthetized with morphine plus sodium pentobarbital. Teridax produced no significant change in blood pressure or respiration until approximately one-half of the infusion was given. Thereafter, a gradual decline in respiration and pulse rates occurred (Table IV).

TABLE III.-INTRAVENOUS TOXICITY OF TERIDAX IN Docs ~

Dog Number

Body Weight Kg.

1,867

10.0

1,874

6.0

1,950

8.2

1,965

9.5

1,991

15.8

2,011

14.5

1,873 1,993 1,996 2,004

9.0 9.3 12.0 10.9

Anesthetic

Dose, Mg./Kg

Morphine sulfate Sodium pentobarbital Morphine sulfate Sodium pentobarbital Morphine sulfate Sodium pentobarbital Morphine sulfate Sodium pentobarbital Morphine sulfate Sodium pentobarbital Morphine sulfate Sodium pentobarbital Chloral hydrate Chloral hydrate Chloral hydrate Chloral hydrate

5.2 24.0 5.3 11 .0 5.1 27.8 5.0 22.0 2 .5 18.2 5.0 16.5 277.0 258.0 213.0 264.0

Solution, Mode

c :SC:

%

1 .o

-Rate

of InfusionMg./m./ Min.

Cc./Min.

Lethal Dose, M d U .

1.35

1.36

506

0.6

0.94

0.93

443

1 .o

0.84

1.0

303

sc iv sc iv sc iv

1.0

1.45

1.5

602

1.0

1.8

1.1

347

1.2

2.6

2.1

689

iV

1.0

2.3 0.4 0.4 1.2

2.6 0.4 0.3 1.2

265 60 103 385

1v

?V

1.0 1 .o 1.2

TABLE IV.-EPFECT OF TERIDAX ON PULSEAND RESPIRATION RATESIN DOGS

Dog Number

1,867 1,874 1,950 1,965 1,991 2,011 1,873 1,993 1,996 2,004

Control

Pulse Rate/Respiration Rate (Per Minute) 20 Minutes After Onset Middle of of Infusion Infusion

Morphine-Sodium Pentobarbital Anesthesia 120/10 100/8 84/4 66/6 90/4 80/6 158/4 138/6 160/4 98/12 94/8 W 6 90/6 118/8 74/7 106/21 100/12 112/23 Chloral Hydrate Anesthesia 152/35 130/38 110/36 156/58 134/60 130/70 118/24 126/27 124/38 120/21 124/22 76/ 8

Just Prior to Death

54/1 72/2 100/4 68/2 92/2 82/5 56/2 104/32 96/0 88I2

August, 1953

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SCIENTIFIC EDITION

TABLE V.-AVERAGE BLOODVALUESFOR MICEFOLLOWING REPEAIED DOSES OF TERIDAX Teridax Dosage.

Red Blood Cell Counts White Blood Per Cu. Mm. Cell Counts Million Animals Per Ca. Mm.

l3,7.77

l6,:wl

Hemoglobin, Gm./100 cc 14.1 14.11

1.5,f):jK

14.3

N o . of

Mg./Q./

-

Day

noo HI )II

Ill

11.1 103

3 JII Controls

10 10

I2.li l o . ti

I

13.lX3.5

14.1

Neutrophils.

%

32.5 32.7

31.1 31.9

Differential Count LymphoMonoBawcytes, cytes, phils,

%

66.1

66.0 68.1 66.6

"/o

% 1.1 1. I 0.5

11.2 0 .I 0.2

1.2

0.3

-

Eosinopbils,

% 0.1 0.1

0.1 0.2

~

TABLE VI.-AVERAGE BODYA N D ORGAN \I\iEICHTS O F

MICE

FOLLOWING REPE.4TED DOSESOF TERIDAX"

Teridax Dosage, Mx./Kg./ Day

No. of Animals

Initial Body Weight

Autopsy Body Weight

Testes Weight

Seminal Vesicle Weight

Spleen Weight

Adrenal Weight

Kidney Liver Weight Weight

Heart Weight

Thymus Weight

900 600 300 Controls

7 12 15 15

19.6 19.2 18.8 19.5

23.8 25.1 24.4 25.1

0.1788 0.1851 0.1946 0.1990

0,0497 0.0548 0.0576 0.0577

0.0895 0.0917 0.0971 0.1081

0.0044 0.0044 0.0051 0.0039

0.458 0.460 0.478 0.497

0.1157 0.1067 0.1067 0.1123

0.0266 0.027i 0.0257 0.0281

1.560 1.614 1.460 1.558

In Grams

Five-Week Oral Subacute Toxicity in Mice.1A five-week, oral, subacute toxicity test was per-

fed daily 1,500 mg./Kg., 750 mg./Kg., and 375 mg./Kg. of the compound, respectively. A fourth formed for Teridax in male Carworth mice weighing control group received the vehicle alone (aqueous 18-24 Gm. Three groups of 15 mice each were fed 0.5% Tween 80). Mortality after twelve weeks was one of ten a t the compound by oral syringe once daily, five days a week, for the duration of the experiment. A the 1,500 mg./Kg. dose (one rat killed on thirtyfourth group of 15 mice was fed the vehicle alone seventh day of experiment because of infection), (aqueous 270 gum acacia) as a control. The mortality zero of ten at the 750 mg./Kg. dose, zero of ten at 375 mg./Kg. and zero of ten at the control level. after five weeks of treatment was as follows: The growth rate and mean body weights were Dosage, normal for compound-fed rats and the controls. Mg./Kg./ GrouD Substance Dav Mortalitv Just prior to autopsy, blood determinations 1 Teridax 900 8/15 showed normal total and differential white blood 2 Teridax 600 3/15 cell counts, red blood cell counts, blood sugars, and 3 Teridax 300 0/15 hemoglobin values in all groups (Table VII). 4 Controls (2% ... 0/15 Gross examination showed no pathological changes. gum acacia) Weights of the testes, seminal vesicles, spleen, liver, At the 900 mg./Kg. dose, two deaths occurred on kidneys, adrenals, heart, and thymus were taken. the second day, one death on the fifteenth and The mean organ weights of the rats treated with twenty-seventh days, and four deaths on the Teridax did not differ from the controls, except for eighteenth day; at 600 mg./Kg., three deaths on some increases in liver weights at 750 and 1,500 the twenty-fifth day. These deaths have been mg./Kg. dose levels, and a decrease in ovarian attributed to the high dosage of compound fed. weight a t the 1,500 mg./Kg. dose level (Table All animals a t the 300 mg./Kg. dosage and in the VIII). Micropathological study of tissues from control group survived. these rats chronically fed Teridax showed an absence Just prior t o autopsy, blood determinations were of cumulative toxicity at all dosage levels. made. The total and differential white blood cell pups Repeated Administration to Dogs.-Seven counts, red blood cell counts, and hemoglobin values were weaned and allowed t o grow t o a body weight were normal for compound-treated mice and con- of 4 4 Kg. During this period, the health of the trols (Table V). At autopsy, body weights and animals was carefully observed and maintained. weights of the testes, seminal vesicles, spleen, liver, Inoculations against distemper were made, and kidneys, adrenals, heart, and thymus were taken; deworming procedures were performed. Blood the average organ weights of the drug-fed mice did examinations established total and differential not differ significantly from the controls (see Table leucocyte counts, red cell counts, hemoglobin, and VI). Gross examination indicated no pathological sugar values t o be at normal levels. Bromsulchanges. A micropathological study of the liver, phalein liver function tests gave normal values, heart, spleen, kidney, lung, pancreas, colon, stomach, and urinary excretion patterns for phenosulfonadrenal, and testis tissues revealed no pathological phthalein indicated normr.1 kidney function. The changes attributable t o the administration of the young dogs were then divided into groups according compound. t o size and sex. One group received orally 450 Twelveweek Chronic Toxicity in Rats.-Teridax mg./Kg. of Teridax, five times per week, and was given orally by stomach tube five days per week, another group of dogs received 450 mg./Kg. of for twelve weeks, t o immature female Sprague- iodoalphionic acid on the Same regimen. After Dawley rats. Three groups of ten rats each were twelve weeks of medication at these high dosages, liver and kidney tests indicate normal function in both groups. Blood sugar levels, white blood cell 1 The authors are indebted to Dr. Frederick Offenkrantz for the histopathologiral examination of animal tissues, and counts, differential counts, red blood cell counts, to Mr. Sidney Neuwirtb for the biometric evaluation of and hemoglobin values also remained normal. data.

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AMERICAN PHARMACEUTICAL ASSOCIATION

TABLE VII.-AVERAGE BLOOD VALUESIN RATSFOLLOWING TWELVE-WEEK CHRONIC TOXICITY TEST

Substance

Dosage, Mg./Kg./ Day

Teridax Teridax Teridax Controls

1,500 750 375 ...

Red Blood Cell No. Counts White Hemo- Blood of Per Blood Cell globin Sugar NeutroAni- Cu. Mm., Counts Per Gm./160 Mg./ phils, Cc. 1 0 0 Cc. % mals Million Cu. Mm.

.

9 10 10 10

7.9 8.0 8.6 8.1

20,250 17,737 21.563 16;971

13.9 13.5 13.7 14.1

74 79 80 85

13.4 20.7 11.7 13.3

Differential Count Lympho- MonoBasocytes, cytes. phils,

%

%

%

83.1 76.4 86.4 83.4

2.3 1.6 1.1 1.7

0.1 0.1 0.1 0.3

Eosinophils,

%

1.1 1.0 0.8 0.6

TABLE VII1.-AVERAGEBODY AND ORGAN WEIGHTS IN RATSFOLLOWING TWELVE-WEEK CHRONIC TOXICITY TESTO No. AuDosage, of Initial topsy PituiSubM / Ani- Body Body Ovarian Uterine Spleen Liver Adrenal JKidney Heart Thymus tary Rg./pDay mals Weight Weight Weight Weight Weight Weight Weight Weight Weight Weight Weight stance Teridax 1.500 9 137.8 213 0.0537 0.365 1.106 10,392 0.0490 1.852 0.685 0.290 0.0134 Teridax 750 10 137.4 218 0,0636 0.424 1,013 9.887 0.0565 1.914 0.702 0.212 0.0122 Teridax 375 10 137.1 214 0.0849 0.392 0.756 8.820 0.0525 1.827 0.617 0.276 0.0140 Controls ... 10 137.3 224 0.0672 0.437 0.883 8.988 0 0510 1.933 0.711 0.214 0.0163 In Grams.

DISCUSSION

SUMMARY

A comparison of Teridax with iodoalphionic acid in dogs has clearly demonstrated this substance to produce a sharper outline of the gall bladder in excellent contrast with adjacent tissues. Comparisons show 150 mg./Kg. of Teridax to produce opacity and definition equal to 300 mg./Kg. of iodopanoic acid. The three contrast agents were studied in the same dogs to minimize individual variation in arriving at estimates of gall-bladder radiopacity. Bile ducts were seen following Teridax in two dogs; no ducts were visible after iodopanoic acid or iodoalphionic acid. Following oral Teridax, excellent visualization has been obtained in clinical studies with normal human subjects, and in the routine examination of patients for gall-bladder disease (7). A good parallel has been found between the gall-bladder opacity and definition, colon opacity, absence of gastrointestinal irritation observed in dogs, and results obtained in man. The similarity between gall-bladder opacity and definition found in man, and that seen in dogs, has been cited by Jones, et al. (3), and Epstein, et al. (4). Shapiro, and Weinberg (7) have shown in man that Teridax does not produce the early and undesirable opacity of the colon commonly observed after iodopanoic acid (8-11). In conformity with these findings, metabolic studies in dogs and man indicate that Teridax, like iodoalphionic acid, is excreted primarily by the kidneys, and iodopanoic acid is excreted in the feces (12). Freedom from emetic reactions and from gastric irritation was noted in the studies with dogs following repeated Teridax doses of 450 mg./Kg./day. Chronic toxicity studies with mice, rats, and dogs at daily oral dosages which were several times the dosage required for human subjects indicate a low toxicity for the compound. The low toxicity of Teridax also is apparent from observations recorded during the routine application of Teridax in human diagnostic procedures. The data demonstrate the safety of Teridax and a low incidence of side effects in clinical usage (7).

Teridax (triiodoethionic acid), a new oral cholecystographic medium, was evaluated in non-anesthetized, trained dogs. At 100 mg./Kg., Teridax visualized the gall bladder more distinctly than 300 mg./Kg. iodoalphionic acid. The new compound at 150 mg./Kg. was as effective as 300 mg./Kg. of iodopanoic acid. Maximal opacity occurred between eight to ten hours with both Teridax and iodoalphionic acid. Very little Teridax appeared in the colon of dogs. The safety of Teridax is indicated by acute toxicity data obtained in mice, rats, guinea pigs, and dogs; the compound was well tolerated in animals (mice, rats, and dogs) receiving repeated massive doses. In dogs, no emetic reactions occurred, nor was there any evidence of gastric irritation. Pharmacodynamic tests with anesthetized dogs have not shown any deleterious effects upon respiration or the cardiovascular system. The available clinical data indicate a close parallel between the gall-bladder opacity and definition, colon opacity, absence of gastrointestinal irritation, and the safety of Teridax in laboratory animals and in man.

REFERENCES (1) Papa, D . . Ginsberg. H. F.. and Lederman. I.. Division of Medical Chemistry, American Chemical Society Meeting, Atlantic City, New Jersey, September 14, 1952; J . A m . Chcm. SOC. In Press. (2) Hoppe, J. 0. (1951). Unpublished data. (3) Jones, G.E,:.Grohowski, A. S.! Robertson, H. D . , Ramsey, G. H.. Schilling. J. A,. and Strain, W. H.. Radiology, 51, 225(1948). (4) Epstein, B. S.,Natelson, S., and Kramer, B., A m . I. Rocnlgcnol., 56, 201(1946). (5) Neuhaus, D., Christman, A. A,. and Lewis, H. B., Proc. SOC.Expll. Biol. Mcd., 78, 313(1951). (6) Litchfield, J. T., and Wilcoxon, F., J . Phormocol. E x p f l . Thcrop. 95 Qg(l949). (7) Shapud, R.’S., Scientific Exhibit. 38th Apnual Meeting Radiological Society of North America. Cincinnati, Ohio,

SCIENTIFIC EDXTION

August, 1953

December 7-12, 1952; Weinberg, C. Richard, “Preliminary Evaluation of a New Cholecystographic Medium-‘Teridax,’ ” (to be published). (8) Christensen. W. R., and Sosman, M. C.. A m . J . Roenlgcnol.. 66,764(1951). (9) Everett, E. F., and Rigler. L. G., Radiology, 58, 524 (1952).

481

(10) Lowman R. M . Stanley H. W. Evans, T. S., and Mendillo, J. C.,’Gasfrocdterdogy’ 21, 254(1952). (11) Abel, M. S.! Lomhoff, ’I. I., and Garcia, C. V.. Permancnfe Foundahon Mcd. Bull. 10. 95(19521. (12) Perlman P. L., Rosinski, R., and Sutter, D.. “Studies on the Absorptidn and Excretion of a New Cholecystographic Agent, Teridax,” (to be published).

The Influence of Emulsifying Agents on the Antiseptic Activity of Certain Dermatologic Preparations* By J. A. WOODt

a n d L.

WAIT RISINGS

Five series of oil-in-water emulsions and four series of water-in-oil emulsions containing antiseptics were tested by the F. D. A. agar cup-plate method to determine the effect of different emulsifiers on their antiseptic values. The results indicated that no one emulsifier could be recommended for all antiseptics, but, in general, oil-in-water emulsions appeared to be more effective vehicles for antiseptics than water-in-oil emulsions. empiricism in dermatologic medication is being removed by the rapid accumulation of scientific knowledge concerning the proper formulation of topical applications. It is now recognized, for example, that emulsions make ideal vehicles for skin medication in many instances. As a result of this recognition many investigations have been conducted in order to determine the most suitable physical properties for these highly specialized preparations. An important factor in the control or variation of the physical properties is the emulsifier used. Since these agents are frequently active chemicals their presence might directly influence to an important degree the therapeutic effect of the medicinal ingredients. If such were the case a change in the nature or composition of the emulsifier might produce a significant alteration in the therapeutic efficiency of the application despite the fact that physically the emulsion was correct. This paper describes an investigation designed to answer, in part, the question of possible change in therapeutic effectiveness due to substitution of emulsifiers.

in each series varied only in the antiseptic incorporated, which was different for every emulsion. This procedure produced 30 emulsions containing separate and distinct antiseptics, 15 of which were oil-in-water and 15 water-in-oil preparations. They were tested for their relative antiseptic abilities by the standard F. D. A. agar cup-plate method, using the unmedicated bases for controls and Staph. aureus as the test microorganism. With these data as a reference point it was practical to vary the emulsifier portion of the two base formulas in order to determine what influence, if any, the change would have on the relative antiseptic values of the emulsions as shown by the F. D. A. procedure. Four additional series of oil-in-water and three of water-in-oil preparations were made. The sequence of antiseptic materials was kept. The only ingredient change was the substitution of a different emulsifier in the basic formulas for each series. Testing of the seven added series by the agar cup-plate method gave comparative data on the influence of five different oil-in-water emulsifiers and four water-in-oil emulsifiers on the release of antiseptic for diffusion through the seeded media. Table I shows the basic formulas and Table I1 shows antiseptics used together with the results of the tests.

EXPERIMENTAL

DISCUSSION

Two standard emulsion formulas were selected for study. One was an oil-in-water base; the other was a water-in-oil base. A series of 15 antiseptic emulsions was made from each. The preparations

Examination of the nine basic formulas used will show an apparent lack of consistency in maintaining the quantitative ratio of the ingredients throughout the series. It was necessary to change the amounts incorporated in order to insure constancy of physical properties in all the preparations. One of the disturbing results was the failure of zones of inhibition to develop with the sulfonamides. chrysarobm, and tyrothricin. Subsequent investigation with sulfathiazole brought out the fact

UCH OF THE

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Received October 30, 1952, from the College of Pharmacy University of Washington Seattle Wash. t part of a thesis submitted dy J. A. Wood in fulfillment of the requirement8 for the degree of Master of Science in Pharmacy at the University of Washington. Present address: Assistant Professor of Pharmacy, University of Saskatchewan. $ Professor of Pbarmacy, University of Washington.