Degradation Products of Streptozocin in Aqueous Saline Solution at pH 4.6
Streptozocin, is a broad-spectrum antibacterial agent produced by Streptomyces achromogenus, and an antitumor agent in clinical use for malignant islet cell cancer of the pancreas. It is also used to induce diabetes in laboratory animals for experimental purposes. In 1967, it was noted that injections of the drug were not always successful in inducing the condition, and degradation of the drug in solution during storage was suspected. Work was done by various researchers which indicated that the drug sometimes would indeed degrade under conditions closely matching the storage conditions, (0.9% aq. NaCl solution, buffered to pH 4.6 with citric acid) but not always. One degradation product was isolated and characterized, and two or three other compounds were thought to remain in the reaction mixture, all difficult to isolate. Several compounds isolated from degradative procedures under various conditions during the structure determination of streptozocin were used as reference compounds in this work. This report presents evidence concerning degradation products of streptozocin in pH 4.6 buffered saline solution which have been isolated and characterized, optimum conditions for the degradative reaction, and miscellaneous data pertaining to the subject.