[Studies on toxicity of clobetasone-17-butyrate (II)--chronic toxicity in rats (author's transl)].

Chronic toxicity of clobetasone-17-butyrate, an anti-inflammatory corticosteroid, was investigated in rats. Subcutaneous administration with the drug at dose of 0.003, 0.01 and 0.03 mg/kg/day for three and six months induced no significant changes in the rats. At 0.1 and 0.3 mg/kg/day, however, some dose-dependent symptoms such as suppression of body weight gain, emaciation, regressive changes in adrenals, lymphatic and hematopoietic tissues, decrease in circulating white blood cell and lymphocyte counts, which have been known as toxic effects of synthetic corticosteroids, were induced. The results indicates that the maximum no-toxic dose of clobetasone-17 butyrate was 0.03 mg/kg/day on this experimental condition. In the recovery test for two months no significant differences in the treated rats from controls were found, suggesting that the toxic effects were reversible in the animals treated at 0.3 mg/kg/day and lower than that.