[Stability of injectable carnosine solutions]

The stability of infusion solutions prepared from carnosine by extraction from biological material was studied. The substance differed from the commercial product (Sigma, USA) obtained by chemical synthesis. The presence in carnosine preparations of free amino acids and a broad spectrum of transient metal ions caused its destruction in solution. Carnosine decomposition was accompanied by its decline in solution with simultaneous increases in free amino acids (L-histidine and beta-alanine). This finding suggests that chemical destruction of carnosine can be mediated by a complex hydrolysis-oxidation mechanism. The effects of temperature, pH; illumination, and other factors on the stability of carnosine solutions during storage were studied and approaches to a stabilization of infusion solutions of the dipeptide elaborated.