An LC method for simultaneous determination of amoxicillin and sulbactam pivoxil in a combination formulation

A simple and accurate liquid chromatography (LC) method is described for simultaneous determination of amoxicillin and sulbactam pivoxil in a combination formulation. Chromatographic separation of the two drugs was achieved on a Hypersil C18.column (250 mm × 4.6 mm, 5 μm) using a mobile phase consisting of a mixture of methanol, acetonitrile, and water (60: 1: 39, v/v/v, pH = 4.5) delivered at a flow rate of 1:0 mL/min, and detection was made at 220 nm. Separation was complete in less than 10 min. The method is linear, precise, accurate, and selective. Linearity, accuracy, and precision were found to be acceptable over the ranges 50.95-509.5 μg/mL for amoxicillin and 46.63-466.3 μg/mL for sulbactam pivoxil. Due to its simplicity and accuracy, the method is suitable for routine quality control analysis of amoxicillin and sulbactam pivoxil in the combination formulation.