Primycin is a topical antibiotic developed in Hungary for the local treatment of certain superficial and deep infections of the skin and subcutaneous tissue. Primycin is a complex of macrocyclic antibiotics comprising 20 compounds. Primycin possesses good in vitro activity against Staphylococcus aureus and coagulase-negative staphylococci, but its activity against Sirepiococctts pyogenes and enterococci is moderate. It is active against Micrococcus and Bacillus spp. but is inactive against Corynebacterium spp. It is inactive against Enterofojcterwceae and Pseudomonas aeruginosa, yeasts, and dermatophytes. The median lethal dose in the mouse is greater than 3,000 mg/kg of body weight orally and 56 mg/kg intraperitoneally. No skin lesions have been observed after chronic cutaneous applications (90 days) in the rabbit.