[Derivatographic analysis of 6-beta-[(hexahydro-1H-azepin-1-yl) methylenamino]penicillanic acid].

Derivatographic analysis of 5 samples of 6-beta-(hexahydro-IH-azepin-I-yl)methylenamino penicillanic acid was performed. In addition to the antibiotic the samples had water and acetone in their composition. No effects associated with changes in the physical and chemical state of the substance were observed on the derivatogramme of the samples containing 0.2 and 0.8 per cent of water up 140 degrees C. With a further increase in the temperature an exothermic effect was observed with maximum at 152--153 degrees C connected with melting and chemical degradation of the substance. The derivatogrammes of the samples containing 89--96.4 per cent of the antibiotic were characterized by an endothermic effect with minimum at 65 degrees C caused by evaporation of acetone and partially water from them and by an exothermic effect with maximum at 120 degrees C practically not accompanied by any change in the weight resulting from chemical interaction of the antibiotic with water. The study showed sensitivity of 6-beta-(hexahydro-IH-azepin-I-yl)methylenaminopenicillanic acid to the presence of even insignificant amounts of water in it, maximum elimination of which from the antibiotic is an important factor of increasing its stability.