Development and validation of a new analytical HPLC method for simultaneous determination of the antidiabetic drugs, metformin and gliclazide.

An efficient and simple HPLC method has been developed and validated for the simultaneous determination of gliclazide and metformin hydrochloride in bulk and was applied on marketed metformin and gliclazide products. The mobile phase used for the chromatographic runs consisted of 20 mM ammonium formate buffer (pH 3.5) and acetonitrile (45:55, v/v) The separation was achieved on an Alltima CN (250 mm × 4.6 mm x5μ) column using isocratic mode. Drug peaks were well separated and were detected by a UV detector at 227 nm. The method was linear at the concentration range 1.25-150 μg/ml for gliclazide and 2.5-150 μg/ml for metformin respectively. The method has been validated according to ICH guidelines with respect to system suitability, specificity, precision, accuracy and robustness. Metformin limit of detection (LOD) and limit of quantification (LOQ) were 0.8 μg/ml and 2.45 μg/ml respectively while LOD and LOQ for gliclazide were 0.97 μg/ml and 2.95 μg/ml respectively.