Development and Validation of Stability Indicating HPLC Method for Simultaneous Determination of Antidiabetic Drugs Metformin Hydrochloride and Glyburide in Tablets

Aim: To develop and validate a stability indicating HPLC method for simultaneous estimation of metformin hydrochloride (MET) and glyburide (GLY) in their combined drug product.

Study Design: All variables were studied to optimize the chromatographic conditions.

Place and Duration of Study: Department of Chemistry, Faculty of Science, Aleppo University, Aleppo, Syria during six months.

Methodology: Bromocriptine mesylate (BCM) was used as internal standard. The determination was performed on a Hichrom 5 C8 column (250 × 4.6 mm i.d., 5 mm particle size); The mobile phase, consisting of a mixture of 0.1 M ammonium acetate (pH 5.0) and methanol (23:77, v/v), was delivered at a flow rate of 0.7 mL min-1, and UV detection was at 230 nm.

Results: The retention times were about 4.2, 6.8 and 10.6 min for MET, GLY and BCM, respectively. Linearity ranges were 0.1 - 300.0 and 0.89 - 311.0 μg mL-1 with limit of detection values of 0.026 and 0.089 μg mL-1 for MET and GLY, respectively. Correlation coefficients (r2) of the regression equations were greater than 0.999 in all cases. Multicomponent dosage form was exposed to thermal, photolytic, acid, alkali and oxidative stress. The method distinctly separated the drugs and degradation products even in actual samples.

Conclusion: According to the validation results, the proposed HPLC method is simple, specific, precise, accurate and robust. Therefore it is appropriate for routine simultaneous quantitative analysis of MET and GLY in raw material and tablet formulation.