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Toxicological information

Repeated dose toxicity: oral

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Administrative data

Endpoint:
short-term repeated dose toxicity: oral
Type of information:
migrated information: read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Non-GLP and non-guideline study with limitations in design and reporting but otherwise acceptable.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2000

Materials and methods

Test guideline
Qualifier:
equivalent or similar to guideline
Guideline:
OECD Guideline 408 (Repeated Dose 90-Day Oral Toxicity Study in Rodents)
GLP compliance:
not specified
Limit test:
no

Test material

Constituent 1
Reference substance name:
Mixture containing zinc 3,5-bis(alpha-methylbenzyl)salicylate
IUPAC Name:
Mixture containing zinc 3,5-bis(alpha-methylbenzyl)salicylate
Test material form:
solid: particulate/powder
Remarks:
migrated information: powder
Details on test material:
The mixture containing zinc 3,5-bis(alpha-methylbenzyl)salicylate is a whitish, non-water-soluble powder.
The chemical composition of the mixture is 80% zinc 3,5- di-(α-methylbenzyl)-salicylate and 20% methylstyrene & styrene polymer. The final concentration of zinc is approximately 7%.
The mixture is emulsified in 0.5% tragacanth solution and a suspension of 5 ml/100g weight is prepared,

Test animals

Species:
rat
Strain:
Wistar
Sex:
male/female
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Source: bred by Messrs. Kitayama LABES Co., Ltd., Kyoto, Japan
- Age at study initiation: Rats of 5 weeks
- Diet (e.g. ad libitum): Solid feed was creatine pellet, Ca-1, and city water was provided ad libitum.
- Water (e.g. ad libitum): Solid feed was creatine pellet, Ca-1, and city water was provided ad libitum.

ENVIRONMENTAL CONDITIONS (The animals were kept in a breeding room with the following conditions):
- Temperature (°C): 22±1
- Humidity (%): 60

- Rats were classified into groups comprising 20 pairs of rats per group. There were 5 groups in total; the mixture containing zinc 3,5-bis(alpha-methylbenzyl)salicylate was administered as follows: 0.1, 1, 10 & 100 mg/kg. There was a control group. The drug was administered orally for 90 days via a stomachic tube.

Administration / exposure

Route of administration:
oral: gavage
Vehicle:
other: gum tragacanth
Analytical verification of doses or concentrations:
not specified
Duration of treatment / exposure:
90 days
Frequency of treatment:
Once daily
Doses / concentrations
Remarks:
Doses / Concentrations:
0, 0.1, 1, 10 and 100 mg/kg bw/day
Basis:

No. of animals per sex per dose:
20
Control animals:
yes, concurrent vehicle
Details on study design:
Rats of 5 weeks, KBL: Wistar, (bred by Messrs. Kitayama LABES Co., Ltd., Kyoto, Japan), were selected and classified into groups comprising 20 pairs of rats per group. There were 5 groups in total; the mixture containing zinc 3,5-bis(alpha-methylbenzyl)salicylate was administered as follows: 0.1, 1, 10 & 100 mg/kg. There was a control group. The drug was administered orally for 90 days via a stomachic tube. The animals were kept in a breeding room where the room temperature was 22±1°C and the humidity 60%. Solid feed was creatine pellet, Ca-1, and city water was provided ad libitum.

Changes in the symptoms of the rats were observed during the full period of administration and an autopsic analysis was carried out as soon as possible after any death. Subsequently the dead rats were fixed in Formaldehyde solution.

The body weight was recorded every other day and the feed and drinking water intake measured every 15 days.

On the day after drug administration was completed, surviving animals were killed in order to analyze whether any abnormality in the internal, organs had occurred.

The weight of organs including brain, hypophysis, thymus, lung, heart, liver, spleen, kidney, adrenal gland, testis, uterus, and ovary was recorded. In addition to the above organs, thyroid gland, stomach to small intestine, pancreas, main artery, mesenteric lymph nodes, prostate, and bone marrow (femur) were removed, fixed in Formaldehyde solution and submitted to histopathological analyses.

Before autopsy, the abdomen of the rats were opened under light ether anesthesia and blood drawn from the descending aorta thereof so that the red cell (RBC) and white cell (WBC) counts could be measured on an automatic blood cell counting unit made by Japan Photo Cell Co., Ltd.. Hemoglobin and hematocrit values were measured on a Sahili hemochronometer and Kubota hematocrit centrifuge, respectively.

Using serum obtained by coagulation and centrifugation of a sample of the blood collected as above, total protein, A/G rate, cholesterol, bilirubin and urea nitrogen (BUN) were estimated; and serum transaminase (GOT and GPT) and alkali phosphatase (ALP) activities were measured, using a Rapid Blood Analyzer (manufactured by Kyoto Daiichi-Kagaku Co., Ltd., Kyoto, Japan, and Chugai Pharmaceutical Co., Ltd., Tokyo, Japan).

The blood serum concentrations of Na and K were measured by flame photometer (made by Toshiba-Beckman) and CL concentration was measured on a Chloride meter (made by Corning Co., Ltd.). In order to avoid any variation after drawing the blood, total fresh blood was used in measuring the blood sugar value by means of a Reflectance meter (made by Ames Co., Ltd.).

24 hour urine samples were collected from a sample of the rats, consisting of 5 males and 5 females from each group. They were placed in a metabolic cage (Natsume KN-646B) after 88 days drug administration, and external appearance, urine volume, pH, sugar, protein, bilirubin, Urobilinogen, occult blood, and ketones were estimated. A urinalysis stick (made by Miluse + Sankyo Co., Ltd.) was used for all the foregoing analyses.

The organs fixed in Formaldehyde solution were embedded in paraffin and examined by thin section microscopy using hematoxylineosin (H-E) stain.

Examinations

Observations and examinations performed and frequency:
CAGE SIDE OBSERVATIONS: Yes
- Time schedule: not specified

DETAILED CLINICAL OBSERVATIONS: No data

BODY WEIGHT: Yes
- Time schedule for examinations: every other day

FOOD CONSUMPTION: yes
-- Time schedule for examinations: every 15 days

WATER CONSUMPTION : Yes
- Time schedule for examinations: every 15 days

OPHTHALMOSCOPIC EXAMINATION: No data

HAEMATOLOGY: Yes
- Time schedule for collection of blood: at termination
- Anaesthetic used for blood collection: yes - ether
- Animals fasted: No data
- How many animals: all
- Parameters examined: red blood cell count, white blood cell count, haemoglobin and haematocrit values

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: at termination
- Animals fasted: No data
- How many animals: all
- Parameters examined: total protein, A/G ratio, cholesterol, bilirubin and urea nitrogen, serum transaminase (GOT and GPT), alkaline phosphatase, sodium, potassium, chloride

URINALYSIS: Yes
- Time schedule for collection of urine: day 88
- Metabolism cages used for collection of urine: Yes
- Animals fasted: No data
- How many animals: 5/sex/group
- Parameters examined: appearance, volume, pH, sugar, protein, bilirubin, urobilinogen, occult blood, ketones

NEUROBEHAVIOURAL EXAMINATION: No
Sacrifice and pathology:
GROSS PATHOLOGY: No data
HISTOPATHOLOGY: Yes
The weight of organs including brain, hypophysis, thymus, lung, heart, liver, spleen, kidney, adrenal gland, testis, uterus, and ovary was recorded. In addition to the above organs, thyroid gland, stomach to small intestine, pancreas, main artery, mesenteric lymph nodes, prostate, and bone marrow (femur) were removed, fixed in Formaldehyde solution and submitted to histopathological analyses.
Statistics:
Statistical analysis: The mean values and standard deviations were calculated for each experimental group and significant differences between male and female values examined. The stochastic significance of differences between the test and control groups was examined by means of a t-test.

Results and discussion

Results of examinations

Clinical signs:
effects observed, treatment-related
Mortality:
mortality observed, treatment-related
Body weight and weight changes:
effects observed, treatment-related
Food consumption and compound intake (if feeding study):
no effects observed
Water consumption and compound intake (if drinking water study):
no effects observed
Haematological findings:
no effects observed
Clinical biochemistry findings:
no effects observed
Urinalysis findings:
no effects observed
Organ weight findings including organ / body weight ratios:
no effects observed
Histopathological findings: non-neoplastic:
no effects observed
Details on results:
Growth curve (see Figs. 1 and 2 of the attached report): Figs. 1 and 2 of the attached report show growth curves. The growth curve of the male 10 mg/kg group is identical to that of the control group, but the increase in weight of the 100 mg/kg group was reduced in the latter period of the trial, resulting in a significant difference in final weights between the experimental and control groups. (P 0.01. See Table 1 of the attached report). There were no differences between any experimental female group and the control group. There were no marked changes in terms of general symptoms of disease, and any slight changes were less than those of the 100 mg/kg group in which a deterioration of the condition of the fur of both male and female animals was observed.

- Feed and water intake (see Figs. 3, 4, 5 & 6 of the attached report): Figs. 3 and 4 of the attached report show food consumption. There is no difference between any male test group and the male control group in respect of food intake during the entire course of the period of administration of the drug, and no female group shows any change until the dose reaches 10 mg/kg, but the 100 mg/kg female group shows a slight decrease in food intake up to 60 days. However, at 75 and 90 days, there is an increase in food consumption. Figs. 5 and 6 of the attached report show drinking water intake. There was some decrease at 30 to 60 days in the male 100 mg/kg group, whereas there was no marked difference between the female drug groups and the female control group. These results show that the administration of the mixture containing zinc 3,5-bis(alpha-methylbenzyl)salicylate has no apparent impact upon either the food consumption or drinking water intake.

- Weights of organs(see Tables 2 & 3 of the attached report): Tables 2 and 3 of the attached report show average weights of the organs. Correlation of changes in weight with dosage administered is indicated, for example, in the changes in weight of female adrenal glands, but such changes were snail. There were also decrease in the weights of male animal hearts and female thymus, but there was no correlation between such changes and the dosage, the fluctuations being quite small.

- Organ weight/body percentage(see Tables 4 & 5 of the attached report): Tables 4 and 5 of the attached report show percentage of organ weight relative to body weight. There is a decrease in the increase in body weight in the male 100 mg/kg group, and a significant increase in the weights of organs such as brain, liver, kidney, adrenal glands and testis. The female 100 mg/kg group also shows an increase in the weights of organs such as the kidney and adrenal glands. There are changes showing a significant difference between the drug groups and the control group but these do not correlate with drug dosage. The changes in male brain and testis, and female liver and kidney occur in both the drug groups and the control group but no stochastical significance can be established.

- Hematological analysis (see Table 5 of the attached report): As shown in Table 5 of the attached report, hematological analysis performed upon completion of drug administration shows that in the male groups, a dose level of 0.1 to 10 mg/kg significantly increases the number of red blood cells, and all the male drug groups show slightly significant increases in hemoglobin. Furthermore, the hematocrit value increased slightly in the 1 and 10 mg/kg groups. In the female groups, although the number of red blood cells increased in the 10 and 100 mg/kg, neither the hematocrit value nor hemoglobin levels were changed. There were no changes in white blood cell count in either the male or female groups.

- Serum-biochemical analysis (see Tables 7, 8, 9, 10 of the attached report): Table 7 of the attached report shows total protein level, A/G ration and blood sugar value. The male 10 & 100 mg/kg groups show slight increases in total protein, and a dosage of more than 1 mg/kg has a tendency to lower the A/G ratio. There is no change in total protein in female groups, but among them the groups receiving the drug show a significant decrease in the A/G ratio. While there is no change in blood sugar levels in male animals, there is a slight significant decrease in female animals in the 10 and 100 mg/kg groups. Table 8 shows cholesterol level, bilirubin and BUN (urea-nitrogen) levels. No apparent fluctuation in the cholesterol level occurs in either male or female groups. The bilirubin level increases slightly in the male animals but not in female animals. BUN levels do not change in male animals, while a slight change is found in the female 0.1 to 10 mg/kg groups, but there is no change in the 100 mg/kg group. Table 9 of the attached report shows GOT, GPT and ALP (alkali phosphatase) activities. No changes correlating with the dose level were found. Table 10 of the attached report shows electrolysis amount of serum. The 100 mg/kg group shows a stochastically significant decrease in Na and CL for both the male and female; a decrease in K also occurs in the female 100 mg/kg group. There were no changes in the 0 to 10 mg/kg groups of animals. As a criterion for judging whether the values obtained in the serum-biochemical analyses were abnormal values or whether they were fluctuations within the normal range of values, we used the results obtained from the control group in the long-range toxicity test which we carried out previously*; the mean values and standard deviation from the mean values.

* Data from 6 tests per each of subacute toxicity (1 to 5 months) and chronic toxicity (6 to 12 months)

All values of total protein obtained in this series of tests fall within the range of normal values, 5.27 to 7.00 g/dl, obtained in the previous experiments. A/G ratio values are so widely scattered that its normal range has not been determined. The normal ranges of blood sugar, cholesterol, bilirubin and BUN levels are 110 to 140 mg/dl, 50 to 60 mg/dl, 0.1 to 0.4 mg/dl and 18.5 to 24.5 mg/dl, respectively. The average values of the groups to which the test material was given fall within these normal ranges. The normal range of enzyme activity is 50 to 110 karmen units for GOT, 20 to 40 karmen units for OPT, and 20 to 40 King-Armstrong units for ALP, all the mean values obtained in this test lying within the normal range. The normal range of electrolysis amount in serum is 130 to 150 mEq/l for Na, 28 to 4.5 mEq/l for K and 90 to 110 mEq/l for CL, the mean values obtained here also falling within the normal range. The foregoing survey shows that since all results obtained from animals receiving the test material fall within the normal range of values for all parameters measured, it may be thought that there is no necessity of regarding the above-mentioned fluctuations particularly as abnormal.

- Urine analysis (see Tables 11 & 12 of the attached report): Tables 11 and 12 of the attached report show the result of analysis of a 24 hour urine sample obtained on the 88th day of the drug administration. Within the exception of the male 100 mg/kg group showing an increase in urine volume, there was no consistent correlation between the control and drug groups in sugar, bilirubin, urobilinoids levels, nor in occult blood or ketone bodies.
- Histopathological investigation: The histopathological research of the following was made; Brain, hypophysis, thyroid gland, thymus, adrenal glands, heart, aorta, spleen, mesenteric lymph nodes, lung, stomach, intestinal duodenum, small intestine, liver, pancreas, kidney, urinary bladder, testis, seminal vesicle, uterus, ovary and muscle (thigh). No marked changes were noted in the following organs in either control or experimental groups: Hypophysis, thymus, adrenal glands, aorta, stomach, testis, seminal vesicle, ovary or muscle.

i) Nervous system: Brain: One animal in the group receiving 0.1 mg/kg showed a localized gliosis (neuroglia) .in the tempral lobe, while congestion occurred in two animals in the female group receiving 100 mg/kg.

(ii) Endocrine system: Thyroid gland: One animal in the female receiving 100 mg/kg had a goiter.

(iii) Circulatory system: Heart: Three animals in the male control group showed an increase in localized stromatic cell accompanied by atrophy and absence of myocardial fiber, and five animals in the male groups receiving 0.5 mg/kg and 1 mg/kg, and three animals in the group receiving 10 mg/kg were seen to have a similar increase. Sometimes minimal fibrosis was also seen. One animal in the female group receiving a dosage level of 0.1 mg/kg developed congestion of the coronary vein.

(iv) Hematopoietic system:
- Spleen: Almost all animals showed minimal hemosiderosis in red marrow.
- Lymph nodes: In addition to the fact that the great numbers of animals including those in the control group had small amounts of plasma cells in the cave of intramedullar, one animal in each of the male and female groups receiving a dosage level of 0.1 mg/kg developed chronic lymphadentis.

(v) Respiratory system: Lung: Although numerous animals, both male and female, from all groups, including the control group, developed inflammation of the lung, there was no marked difference in either frequency or extent between the control group and the groups receiving the drug.

(vi) Liver: Three animals in the male control group developed a small round cell infiltration showing a slight extension of the Glisson capsule, whereas three animals in the female control group developed small round cell infiltration, which are localized, in both the Glisson capsule and lobule. Small localized round cell infiltration were seen in the Glisson capsule and the periphery of the central vein and lobule. Six males and three females in the 0.1 mg/kg group; five males in the 1 mg/kg group; seven males and five females in the 10 mg/kg group and thirteen males and five females in the 100 mg/kg group developed this condition. One animal in each of the male groups receiving dosage levels of 0.1 and 100 mg/kg developed localized necrosis of the liver cell. Furthermore, four female animals in the 0.1 mg/kg group, six females and one male in the 1 mg/kg group, one female and two males in the 10 mg/kg group, and two females and three males in the 100 mg/kg group were stained heavily with eosin, having developed pyknosis and atrophy of the liver, throughout the lobule, but it was not apparent whether this degeneration was linked to drug administration, or to natural (or artificial) causes. Two female animals in the group receiving 0.1 mg/kg, three male animals in the group receiving 1 mg/kg, one male and one female animal in the group receiving a dosage level of 10 mg/kg and three male animals and two female animals in the group receiving 100 mg/kg showed fat deposits in cells in the central area or at the periphery of the lobule.

(vii) Digestive system:
- Intestinal duodenum and small intestine: Almost half of all animals, both the male and female, in all the experimental groups including the control group, developed minimal catarrhal inflammation.
- Spleen: Although there were no marked changes in parenchma, localized vacuolar nephropathy of cento-acinar cells was found in one animal in the male 0.1 mg/kg, three animals in the 1 mg/kg, three animals in the 10 mg/kg and one animal in 100 mg/kg.

(viii) Urinary tract system:
- Kidney: Protein casts lightly stained with eosin appeared in the distal urinary tubule of animals in all experimental groups including the control group. There were equal numbers of such cases in all groups. Some cases were found in almost all animals.
Localized small round cell infiltration or minimal fibroplasia, which is ascribed to Plelitis was found in one animal in each of the male and female groups receiving a dosage level of 0.1 mg/kg as well as the female group receiving 100 mg/kg.
- Urinary bladder: Two animals in each of the male group receiving 0.1 and 1 mg/kg developed enlargement of the urinary bladder.

(ix) Reproductive system:
- Uterus; Polyps were found in the endometrium of one animal in each of the groups receiving dosage levels of 1 and 10 mg/kg and two animals in the group receiving 100 mg/kg. Endometritis was found in one animal in each of the groups receiving 10 and 100 mg/kg (see Table 13 of the attached report). As shown in Table 13 of the attached report, the foregoing surveys show that there were found various kinds of histopathological changes in organs, but, if accidental changes are excluded, no significant differences between the control groups and the drug group were found.
The histopatholgical change proportional to the dosage levels was not found in the group receiving the drug and, according to the histopathological survey, the difference in the response is not found also between the male and the female. That is, in terms of histopathology, no genuine change ascribed to the administration of the mixture containing zinc 3,5-bis(alpha-methylbenzyl)salicylate is acknowledged.

- Comment: In view of the fact that the mixture containing zinc 3,5-bis(alpha-methylbenzyl)salicylate is to be used in the manufacture of pressure sensitive paper, and not to be taken orally, and that the 50 % lethal dose given by mouth is so high (4000 mg/kg for mice and 2000 mg/kg for rats), it is a very safe substance. This test examined the toxicity of the mixture containing zinc 3,5-bis(alpha-methylbenzyl)salicylate given orally to rats for 90 days. The results show that several animals receiving 100 mg/kg of the mixture containing zinc 3,5-bis(alpha-methylbenzyl)salicylate died, but in the range of 0.1 to 10 mg/kg, no death occurred. According to the results of the autopsy, death was caused by hyposthenia, which had no distinctive toxicity, following intense inflammation of the lung. Histopathological examination showed that death might be presumed to be caused by the decline of physical strength induced by the toxicity produced by the continuous administration of large dosages of the mixture containing zinc 3,5-bis(alpha-methylbenzyl)salicylate giving rise to a severe infection of the lung ascribed to environmental factors. In both male and female animals in the 100 mg/kg group, there was a slight increase in relative weight (body weight percentage) in area including the kidney and adrenal glands. However, there was no correlation with dosage levels, and there was no difference between the growth curves of control groups and groups receiving the mixture containing zinc 3,5-bis(alpha-methylbenzyl)salicylate. Although there was some variation in results from hematological, cerum-biochemical and urinological analyses, all values fell within the normal range of values. Excluding accidental lesion, histopathological analysis showed abnormalities in the lung, liver and kidney. Since the lesion of the lung may be ascribed to an environmental factor (infectious disease) and that of the kidney ascribed to a nutritional factor (protein-rich feed), neither of the above abnormal findings was thought to be caused by the administration of the mixture containing zinc 3,5-bis(alpha-methylbenzyl)salicylate. The abnormality of infiltration into small round cells in the liver occurs in both control and drug groups, but localized necrosis, hepatocyte pyknosis and fatty deposits were found only in the group receiving the drug, so some adverse effect on liver function is suggested. However, there is no correlation of such effects with dosage level, nor was any change in liver function found in the biochemical investigation. Therefore, it was concluded that the liver disorder was not the result of administration of doses of the mixture containing zinc 3,5-bis(alpha-methylbenzyl)salicylate. 90 days oral administration of the mixture containing zinc 3,5-bis(alpha-methylbenzyl)salicylate to rats resulted in death in the group receiving a dose of 100 mg/kg, but dosage levels of less than 10 mg/kg had no ill effects. The essential nature of the toxicity of the mixture containing zinc 3,5-bis(alpha-methylbenzyl)salicylate has not yet been elucidated, but it seems likely that a decrease in physical condition renders individual animal more susceptible to environmental factors.

Effect levels

open allclose all
Dose descriptor:
NOAEL
Effect level:
10 mg/kg bw/day (nominal)
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: lower body weight, adverse clinical signs and mortality at 100 mg/kg bw/day NOAEL for the mixture (containing 80% zinc 3,5-bis(alpha-methylbenzyl)salicylate).
Dose descriptor:
NOAEL
Effect level:
8 mg/kg bw/day (nominal)
Based on:
other: zinc 3,5-bis(alpha-methylbenzyl)salicylate
Sex:
male/female
Basis for effect level:
other: lower body weight, adverse clinical signs and mortality at higher dose level NOAEL for zinc 3,5-bis(alpha-methylbenzyl)salicylate

Target system / organ toxicity

Critical effects observed:
not specified

Applicant's summary and conclusion

Conclusions:
The subchronic toxicity of the test material was examined in groups of 20 males and female rats dosed by gavage at 0, 0.1, 1, 10 or 100 mg/kg bw/day for 90 days. There was no evidence of significant target organ toxicity. For the mixture containing 80% zinc 3,5-bis(α-methylbenzyl)salicylatethe overall NOAEL was 10 mg/kg bw/day following 90 day exposure therefore, for zinc 3,5-bis(α-methylbenzyl)salicylate , the overall NOAEL was 8 mg/kg bw/day.
Executive summary:

Conclusion: The oral administration of the test material to rats for 90 days suggests the following conclusions;
 
(i.) Death occurred in several animals in the group receiving 100 mg/kg, the mortality rate being 5% for male and 10% for females animals. Within the range of 0.1 to 10 mg/kg of administration, no death occurred.
 
(ii) There was no difference between the growth curve of the control group and that of the group to which the drug was administered. Death caused by inhibition of body: weight (hyosthenia) was found in several individuals of the group receiving 100 mg/kg only and it may be considered that such deaths could not be attributed directly to the test material but to the exacerbation of infectious diseases of lung.
 
(iii) Neither hematologic analysis, biochemical analysis of serum nor urinary analysis show any apparent influence of administration of the test material.
 
(iv) Histopathological analysis shows mainly accidental, environmental and nutritional abnormalities, the specific fluctuation by the administration of the test material not being identified.
 
(v) From our investigation, we have found that the maximum safe dose of the test material is 10 mg/kg/day, or 600 mg per day for one adult.

For the mixture containing 80% zinc 3,5-bis(α-methylbenzyl)salicylate the overall NOAEL was 10 mg/kg bw/day following 90 day exposure therefore, for zinc 3,5-bis(α-methylbenzyl)salicylate, the overall NOAEL was 8 mg/kg bw/day.