Some Observations on the Pharmacology of Clofazimine (B663)

Abstract Chemical methods are described for the determination of clofazimine in serum, urine, and feces, and in homogenates of liver and spleen. Feeding clofazimine to mice resulted in a large accumulation of crystalline drug in the liver and spleen. When dosage with clofazimine was terminated tissue and serum concentrations fell extremely slowly, at rates over a period of 4 months equivalent to a half-life of about 70 days. The concentrations of clofazimine were also measured in the serum, urine, or feces of leprosy patients and a healthy volunteer. Clofazimine appeared to be incompletly absorbed in man. The relevance of these findings to the treatment of leprosy with clofazimine is discussed.