Registration Dossier

Administrative data

Endpoint:
short-term repeated dose toxicity: dermal
Data waiving:
study scientifically not necessary / other information available
Justification for data waiving:
other:
Cross-reference
Reason / purpose:
data waiving: supporting information
Reference
Endpoint:
short-term repeated dose toxicity: oral
Type of information:
experimental study
Adequacy of study:
supporting study
Study period:
30 June 1987 to 11 August 1987
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
study well documented, meets generally accepted scientific principles, acceptable for assessment
Remarks:
Study conducted to GLP in accordance with recognised guideline but without formulation analysis or stability data.
Qualifier:
according to
Guideline:
OECD Guideline 407 (Repeated Dose 28-Day Oral Toxicity in Rodents)
Deviations:
no
GLP compliance:
yes
Limit test:
no
Species:
rat
Strain:
other: CD (Sprague-Dawley derived)
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS- Source: Charles River Breeding Laboratories, Inc. Wilmington, MA 01887, USA- Age at study initiation: 42 days- Weight at study initiation: males 183-222g (mean = 201g), females 119-162g (mean = 134 g)- Fasting period before study: Overnight- Housing: Suspended stainless steel wire mesh, doubly housed during first 10 days of acclimation perod and then individually housed thereafter.- Diet (e.g. ad libitum): ad libitum (Purina Certified rodent chow #5002)- Water (e.g. ad libitum): ad libitum- Acclimation period: 14 daysENVIRONMENTAL CONDITIONS- Temperature: monitored- Humidity (%): monitored- Photoperiod (hrs dark / hrs light): 12 hours continuous light/dark.IN-LIFE DATES: 30 June 1987 to 11 August 1987
Route of administration:
oral: gavage
Vehicle:
corn oil
Details on oral exposure:
PREPARATION OF DOSING SOLUTIONS: The test article was diluted in corn oil.VEHICLE- Justification for use and choice of vehicle (if other than water): Corn oil was used as the substance formed stable homogenous solutions in this vehicle- Concentration in vehicle: Dose-dependent Low – 50 mg/mlIntermediate – 158 mg/mlHigh – 500 mg/ml- Amount of vehicle (if gavage): 2 ml/kg
Analytical verification of doses or concentrations:
no
Duration of treatment / exposure:
Test duration: 28 days, with 14-day recovery group (5/sex) at high dose level.
Frequency of treatment:
The substances was administered daily, for 28 consecutive days, by gavage. Control animals were treated in an identical manner with 2 ml/kg/day of arachis oil.Recovery group animals were maintained for a further fourteen days treatment-free period following termination of treatment.The volume of test and control material administered to each animal was based on the most recent bodyweight and was adjusted at weekly intervals.
Remarks:
Doses / Concentrations:0mg/kg bw/dayBasis:actual ingested
Remarks:
Doses / Concentrations:50 mg/kg bw/day Basis:actual ingested
Remarks:
Doses / Concentrations:158 mg/kg bw/dayBasis:actual ingested
Remarks:
Doses / Concentrations:500 mg/kg bw/day Basis:actual ingested
No. of animals per sex per dose:
5 animals of each sex (m/f) were allocated to the low and intermediate test dose groups. 10/sex allocated to control and high dose group (5/sex in main study and 5/sex in recovery groups).
Control animals:
yes, concurrent vehicle
Details on study design:
- Dose selection rationale: Results of Preliminary Range Finding study.- Rationale for animal assignment (if not random): Random- Rationale for selecting satellite groups: Regulatory requirement- Post-exposure recovery period in satellite groups: 14 days, treatment free
Positive control:
Not Used
Observations and examinations performed and frequency:
CAGE SIDE OBSERVATIONS: Yes - Time schedule: Twice daily.DETAILED CLINICAL OBSERVATIONS: Yes - Time schedule: Twice dailyBODY WEIGHT: Yes - Time schedule for examinations: Day 1 and weekly thereafter.FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study): Not applicableFOOD EFFICIENCY:- No dataFOOD CONSUMPTIONFood consumption was recorded for each cage group at weekly intervals throughout the study.WATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study): Not applicableOPHTHALMOSCOPIC EXAMINATION: No HAEMATOLOGY: Yes - Time schedule for collection of blood: Day 28 and day 42 for the recovery groups- Anaesthetic used for blood collection: No - Animals fasted: No- How many animals: all- Parameters examined: Haemoglobin, Erythrocyte count, Haemotocrit, Erythrocyte indices, total leucocyte count, differential leucocyte count, platelet count, reticulocyte count, prothrombin time, activated partial thrombopastin time.CLINICAL CHEMISTRY: Yes - Time schedule for collection of blood: Day 28 and day 42 for the recovery groups- Animals fasted: No - How many animals: all- Parameters examined: Urea, glucose, total protein, albumin, albumin/globulin ratio, sodium, potassium, chloride, calcium, inorganic phosphorus, gamma GT, ASAT, ALAT, AP, creatinine, triglycerides, total cholesterol, total bilirubin, bile acidsURINALYSIS: Yes - Time schedule for collection of urine: During week 4 and during week 6 for recovery group animals- Metabolism cages used for collection of urine: Yes- Animals fasted: Yes - Parameters examined: gross apearance, microscopic analysis, Ketones, Specific Gravity, bilirubin, pH, protein glucose, urobilirubin, reducing substances, blood. NEUROBEHAVIOURAL EXAMINATION: No
Sacrifice and pathology:
GROSS PATHOLOGY: Yes DETAILS: Full external and internal examination, any macroscopic abnormalities were recorded..HISTOPATHOLOGY: Yes Samples from the following tissues were removed from all animals and preserved in buffered 10% formalin except where stated.The following tissues:-Adrenals, aorta, bone and bone marrow, brain, caecum, colon, duodenum, epididymes, eyes, gross lesions, heart, ileum, jejenum, kidneys, liver, lungs, lymph nodes, mammary gland, muscle, oesophagus, ovaries, pancreas, pituitary, prostate, rectum, salaivary glands, sciatic nerve, seminal vesicles, skin, spinal cord, spleen, stomach, testes, thymus, thyroid/parathyroid, trachea, urinary bladder, uterus and cervix, vagina
Other examinations:
None
Statistics:
Parameters analysed statistically: body weights, food consumption, hematology, clinical chemistry and terminal organ and body weights and organ/body weight ratios.Statistical evaluation was not performed when the standard deviation for the control group or more than one group is 0.0, due to lack of variance. If a standard deviation for one treated groupp is 0.0, or when N is less than or equal to two animals for any treated group, thevariances of the remaining groups were tested using the same procedure outlined below. If the N for the control group is less than or equal to two animals, no statistics are presented due to lack of variance.Statistical evaluation of equality of means was made by the appropriate one way analysis of variance technique, followed by a multiple comparison procedure if needed.
Clinical signs:
no effects observed
Description (incidence and severity):
Mortality. There was 1 unscheduled death on the study but it was unrelated to treatment.
Mortality:
no mortality observed
Description (incidence):
Mortality. There was 1 unscheduled death on the study but it was unrelated to treatment.
Body weight and weight changes:
no effects observed
Food consumption and compound intake (if feeding study):
no effects observed
Food efficiency:
not examined
Water consumption and compound intake (if drinking water study):
not examined
Ophthalmological findings:
not examined
Haematological findings:
effects observed, treatment-related
Description (incidence and severity):
Minor changes were observed, all but one were resolved during the recovery period.
Clinical biochemistry findings:
no effects observed
Urinalysis findings:
no effects observed
Behaviour (functional findings):
not examined
Organ weight findings including organ / body weight ratios:
effects observed, treatment-related
Description (incidence and severity):
Kidney and liver weights were increased but recovery was evident and these changes were considered to be not adverse.
Gross pathological findings:
no effects observed
Histopathological findings: non-neoplastic:
effects observed, treatment-related
Description (incidence and severity):
For both sexes at 750 mg/kg bw/day, histopathological examination revealed centrilobular hypertrophy for the liver, which was considered to be non-adverse.
Histopathological findings: neoplastic:
no effects observed
Details on results:
MortalityOne mid-dose (158 mg/kg bw/day) female was found dead on Day 4. No cause of death was apparent from gross postmortem examinations. Because this isthe only animal which died and no mortality was seen in the 500 mg/kg bw/day group, this death does not appear to be related to test material administration.Physical observationsAntemortem signs in the animal which dies included tremours, red nasal discharge, soft stool and urinary staining of the fur. Other abnormalities commonly seen in laboratory rats occurred sporadically. No efect of test material administration was apparent.Body weightsMean body weights for treated animals were comparable or greater tha weights of control animals. No statistically significant differences were seen, and no effect of test material administration was evident.Food consumptionMean food consumption values for treated animals were comparable to or greatter than control values. Statistically significant increases in food consumption, relative to control values, occurred inthe high-dose males for the last three weeks of the study. This difference is not considered to represent an adverse effect of the test material.Clinical Laboratory studiesHaematologyMean heamaglobin and heamatocrit values for high dose males and females were slightly (7 to 9%) lower than mean control values at study termination. Differences from control were statistically significant for the heamoglobin values for the males and for the haematocrit values for both sexes. After the two week recovery period, values were similar to (within 2 to 4% of) control values, although the haemoglobin value for males was still statistically significantly lower than the control value. Haemoglobin and Haematocrit values for low and mid-dose groups and total erythrocyte values for all treated groups were comparable to control values.Evaluation of total and differential leukocyte values and coagulation studies (platelets, prothrombin time and activated partial thromboplastin time) revealed no evidence of an effect of the test material administration.Clinical chemistryEvaluation of clinical chemistry values revealed no apparent adverse effect of test material administration. Although some statistically significant differences between values for control and treated groups were seen at study termination (decreases in serum glutamic oxaloacetic tranaminase values and increases in serum albumin levels for mid- and high-dose males increases in triglycerides for high-dose females), values were generally within normal ranges and the nature of the differences was not suggestive of a toxic effect. Statistically significant differences between values for control and treated groups were also noted sporadically at termination of recovery period; none of the differences seen were considered indicative of test material related toxicity.UrinalysisEvaluation of urinalysis data revealed no apparent effect of test material administration.Terminal organ and body weights and organ/body weight ratiosMean kidney weights and kidney/body weight ratios for treated males were higher than mean control values at study termination. Differences were dose-related, i.e., minimal (5 to 6%) at the low dose, slight (12 to 14%) at the mid-dose and moderate (22%) at the high dose, the mean kidney/body weight ratio for the high-dose group was statistically significant (p =< 0.01) higher than the control mean. Similar differences were not apparent in females, nor were any differences seen in kidney weights of control and high-dose males held for a two-week recovery period. In teh absence of any renal pathology or any evidence of impaired renal function based on clinical laboratory or urinalysis values, the differences seen at termination of the dosing period appear to representa reversible metabolic response to test material administration.Liver weights and liver/body weight ratios for the mid- and high-dose males and females were higher than mean control values at study termination. The difference in liver/body weight ratio for the mid-dose males was statistically significant at p =< 0.05, and the differences for all values for high-dose males and females were statistically different at p =< 0.01. Values for high-dose animals at termination of the recovery period were slightly higher than concurrent control values, although differences were less pronounced (only difference in liver/body weight ration for males continued to exhibit statistical significance).Microscopic pathology findings of centrilobular hypertrophy in treated females may correlate with these changes, however, similar microscopic changes were not seen in livers of treated males. The absence of any indication of hepatic toxicity in clinical laboratory studies and the recovery seen during the two-week treatment-free period suggest that the changes represent a reversible metabolic response to test material administration.Weights of other organs evaluated (adrenals and testes) were comparable for control and treated groups.PathologyGross postmortem examination revealed few gross lesions, those which were noted occurred sporadically in control and treated groups and were not considered indicative of a test material effect.MIcroscopic examinsation revelaed hypertrophy of the centrilobular hepatocytes in treated females (1 of 5 low-dose, 2 of 5 mid-dose and 5 of 5 high-dose animals) killed at termination of test material administration. Similar changes were not evident in treated males or in control and high-dose females held for a two-week recovery period. The changes appear to represent a reversible matabolic response to test material administration.Other microscopic abnormalities occurred sporadically and/or with similar incidences in control and treated animals.
Dose descriptor:
NOAEL
Effect level:
> 500 mg/kg bw/day (actual dose received)
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: Effects noted in main test groups reversible in recovery dose group
Critical effects observed:
not specified
Further details not considered necessary .
Conclusions:
Treatment of rats at dosages up to 500 mg/kg bw/day for twenty eight consecutive days was well tolerated and the ‘No Observed Adverse Effect Level’ (NOAEL) for toxicity was considered to be 500 mg/kg bw/day
Executive summary:

Test Guidance

OECD Guideline No. 407

Method

This study was designed to assess the toxicity of the test material when administered orally, via gastric intubation to 45 Sprague-Dawley CD rats at dose levels of 50, 158 and 500 mg/kg/day at a dose volume of 2.0 ml/kg/day. The test substance was administered seven days/week over a four week period. Control animals (10/sex) received the vehicle, corn oil, at the same dose volume as adminstered to the treated animals. Body weight and food consumption measurements were performed on all animals pretest and weekly during the treatment period. Physical observations were conducted on all animals prior to each administration of the test material. Hematology and clinical chemistry parameters were evaluated for all animals at study termination and prior to recovery sacrifice. After approximately four weeks of treatment, half of the control and high-dose animals (5/sex/group), half of the mid-dose females (5), all of the low-dose animals (5/sex) and all of the mid-dose males (5) were sacrificed, selected organs were weighed and organ/body weight ratios were calculated. Complete gross postmortem examinations were performed on all animals and histopathological evaluation of selected tissues were performed on all animals. After a two-week recovery period, all surviving animals were sacrificed, selected organs were weighed and organ/body weight ratios were calculated. Complete gross postmortem examinations were performed on all animals and histopathological evaluation of selected tissues were performed on all animals.

Results

One mid-dose female was found dead on day 4. No cause of death was apparent from gorss post mortem examinations. Because this was the only animal which died and no mortality was seen in the high-dose group, this death does not appear to be related to test material administration.

Evaluation of physical observations, body weight and food consumption data, clinical laboratory studies, urinalysis data and gross postmortem observations revealed no adverse effects of the test material administration.

Mean haemoglobin and haematocrit values for high-dose males and females were slightly lower than mean control values at study termination, but recovery was apparent during the two-week recovery period. Evaluation of total and differential leukocyte values and coagulation studies revelaed no evidence of an effect of test material adminstration.

Mean kidney weights and kidney/body weight ratios for treated males were higher than control values at study termination. differences were dose-related (minimal at the low dose, slight at the mid-dose and moderate at the high-dose). Similar differences were not apparent in females, nor were any differences seen between kidney weights of control and high dose males held for a two-week recovery period. In the absence of any renal pathology or any evidence of impaired renal function based on clinical laboratory and urinalysis values, the differences seen at the termination of the dosing period appear to represent a reversible metabolic response to test material administration.

Liver weights and liver/body weight ratios for mid- and high-dose males and females were higher than mean control values at study termination; differences at the high-dose level were pronounced (approximately 40 to 50% higher than control values). Values for high-dose animals at termination of the recovery period were only slightly (less than 20%) higher than concurrent control values. Microscopic examination revealed hypertrophy of the centrilobular hepatocytes in the treated animals (1 of 5 low-dose, 2 of 5 mid-dose and 5 of 5 high-dose animals) killed at termination of test material administration. Similar changes were not evident in control and high-dose females held for a two-week recovery period, and microscopic changes were not seen in livers of treated males. The absence of any indication of hepatic toxicity in clinical laboratory studies and the recovery seen during two-week treatment-free period suggest that the changes seen represent a reversible metabolic response to test material administration.

Conclusion

Treatment of rats at dosages up to 500 mg/kg bw/day for twenty eight consecutive days was well tolerated and the ‘No Observed Adverse Effect Level’ (NOAEL) for toxicity was considered to be 500 mg/kg bw/day

Data source

Materials and methods

Results and discussion

Applicant's summary and conclusion