Laboratory evaluation of a new long-acting 3-azinomethylrifamycin FCE 22250.

FCE 22250 (3-(N-piperidinomethylazino)methylrifamycin SV) is a member of the new class of 3-azinomethylrifamycins characterized by a long persistance in animals, a good oral absorption and a broad antibacterial spectrum including mycobacteria. In the experimental mice infection sustained by Mycobacterium tuberculosis H37Rv, FCE 22250 shows an efficacy 14 times higher than rifampicin and is still therapeutic when administered once every three weeks.