Sulfapyridine

Endpoint summary

Description of key information

Available data is not sufficient to conclude the repeated dose toxicity of sulphapyridine.

Key value for chemical safety assessment

Repeated dose toxicity: via oral route - systemic effects

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Study duration:

subacute

Species:

other: rats, mice and monkey

Repeated dose toxicity: inhalation - systemic effects

Endpoint conclusion

Endpoint conclusion:

no study available

Repeated dose toxicity: inhalation - local effects

Endpoint conclusion

Endpoint conclusion:

no study available

Repeated dose toxicity: dermal - systemic effects

Endpoint conclusion

Endpoint conclusion:

no study available

Repeated dose toxicity: dermal - local effects

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

There is one sub-chronic study (H. B. VAN DYKE, et al.)conducted with sulfapyridine administered to 3 species (i.e. rats, mice and monkey). In the case of mice, mice were fed the Sherman No. 1 diet containing the drugs in concentrations of 1 and 2 %. Mean of total dose eaten by survivors: 0.814 g and 1.477 g at the dose of 1% and 2%, respectively. And groups of growing albino rats were fed diets containing 0.5 and 1 % of the drug for a period of 57 days. No additional information was revealed except that no deaths occurred. In the cases of monkey,the drug as the free acid was administered by stomach tube to monkeys in a daily dose of 0.4 g per kilo body weight. Six of 7 monkeys receiving sulfapyridine began to exhibit hematuria and albuminuria after a few days and at necropsy were found to be suffering from unilateral or bilateral hydroureter and hydronephrosis.

However, in the case of monkeys, the study will be given less weight as there is only dose level applied and no effects with dose-related trend were observed during the test.

In another study (H. A. WALKER, et al. 1940), groups of young rats (Long-Evans strain; 7 males and 7 females in each group) were fed diets containing 0.5 or 1.0 percent of the drug for a period of 50 days. During the test, no gross or microscopic changes which could be attributed to drug were found in the livers. The spleens of all animals were normal. Microscopically there was a reduction or disappearance of the germinal centers of the malpighian bodies with an accompanying loss of lymphocytes from the mantle and marginal zones. Differential white cell counts were made on all animals at the conclusion of the experiment and little or no difference in the blood picture among the animals.

As a supporting study investigated by JOHN A. KOLMER and ANNAM . RULE., of 16 mice given 0.160 g by intra abdominal injection immediately after inoculation, 6 hours later and thereafter twice daily for 5 days, 4 survived while the lives of 6 were prolonged 1 to 5 days beyond the survival of 4 untreated controls which succumbed in 24 to 72 hours after inoculation.

Available data is not sufficient to derive the NOAEL value under the experimental conditions and cannot provide the scientific details that can be obtained from well-conducted animal studies. Therefore, available data is not sufficient to conclude the repeated dose toxicity of sulphapyridine.

Justification for classification or non-classification

As no scientific design details can be provided during the studies and there is no strong and reliable evidence associating the repeated exposure to the substance with a consistent and identifiable toxic effects. According to CLP ( Regulation EC No. 1272/2008), the available data is inconclusive for classification of specific target organ toxicity.