European Medicines Agency Veterinary Medicines and Inspections

1. Avilamycin is an orthosomycin antibiotic complex produced by the fermentation of Streptomyces viridochromogenes. Orthosomycin antibiotics are divided into two groups: those that contain an aminocyclitol residue and those that are esters of dichlorisoeverninic acid. Avilamycin falls into the latter group as do the evernimicins. Avilamycin is primarily active against gram-positive bacteria. The fermentation product comprises one major factor, avilamycin A, and 15 minor factors: avilamycin A’, B, C, D1, D2, E, F, G, H, I, J, K, L, M and N. Specifications for purity of the dried fermentation product are: avilamycin A greater or equal to 60%, avilamycin B less than 18% (avilamycin A plus B greater or equal to 70%) and the other single factors less than 6%. The safety studies were carried out using avilamycin as fermentation product, with different degrees of purity or as pure (crystalline) product. The factor composition and purity of avilamycin differed between studies.