Amoxicillin sodium-potassium clavulanate: evaluation of gamma radiation induced effects by liquid chromatography on both the individual drugs and their combination

The effects of gamma irradiation on the stability of potassium clavulanate, amoxicillin sodium and their combination were investigated. A decrease in purity and increase in degradation products up to 30 days after the irradia tion were evaluated by reversed phase HPLC. The comparison between unirradi ated and irradiated amoxicillin sodium, performed within 24 h following the irradiation process, showed no significant increase in the pre-existing im purities and no evidence of newly induced degradation products. On the cont rary, an appreciable increase in the content of some impurities was evidenc ed 30 days after the irradiation. The chromatographic profile of irradiated potassium clavulanate showed the appearance of one unidentified new produc t and a slight increase of one pre-existing impurity. No further change in the impurity content was noted 30 days after the irradiation. The amoxicill in sodium-potassium clavulanate combination underwent the same kind of radi ation induced degradation as the single compounds. (C) 1999 Elsevier Scienc e B.V. All rights reserved.