Basic experiments with clotrimazole administered orally.

A series of experiments was carried out with the antimycotic agent clotrimazole to establish MICs against a number of different yeasts and to estimate its blood levels following oral administration. Marked differences were noted between the MIC against A and B serotypes of Candida albicans in its yeast-like cell form, that against Type B being nearly 10-times higher than against Type A. Against the mycelial form, however, the MIC was much lower and there was little difference between the levels for the two serotypes. Clotrimazole administered in oral tablet form appeared to be poorly absorbed, little being transferred to the blood. Urinary levels were low and large amounts of the drug were detected in the faeces. Serum levels were below MIC levels in all cases examined. Blood levels 3-times as great as those after the same dosage in tablet form were produced when clotrimazole was given in oil solution and even with 250 mg, effective blood levels were achieved and maintained.