Bioavailability and chemotherapeutic activity of clofazimine against Mycobacterium avium complex infections in beige mice following a single implant of a biodegradable polymer.

We have studied the bioavailability of clofazimine following administration of a single dose of the drug in the biodegradable polymer polylactic-co-glycolic acid (PLGA). We compared the levels of clofazimine achieved in the liver with single implants with those obtained with daily oral treatment. Even though the levels achieved with implants were much lower than those obtained after daily oral treatment, they were higher than the MIC of clofazimine for Mycobacterium leprae, Mycobacterium tuberculosis and Mycobacterium avium complex (MAC). Experimental studies in beige mice after infection with MAC strain 101 showed similar reductions in cfu counts, after both single dose polymer and daily oral treatment. Macroscopically, hyperpigmentation giving an orange-yellow colour to all visceral organs, was seen in animals after daily oral treatment but not in those animals that received polymer implants.