Asian Journal of Research in Chemistry

This paper presents the stability indicating method for the simultaneous analysis of sitagliptin phosphate monohydrate and metformin hydrochloride using High Performance Thin Layer Chromatography (HPTLC) with densitometric detection. Separation of both the drugs was performed on silica gel G 60F₂₅₄ plates with detection wavelength of 216 nm. The mobile phase is comprised of acetonitrile-methanol-glacial acetic acid (7.0: 3.0: 0.02 v/v/v). The Rf values were found to be 0.21 ± 0.035 and 0.53 ± 0.029 for sitagliptin phosphate monohydrate and metformin hydrochloride, respectively. The linear regression analysis data for the calibration plots showed good linear relationship with respect to peak area in the concentration range 8–64 ng/band of sitagliptin (with r= 0.9992) and 80–640 ng/band of metformin (with r= 0.9994). The method was validated as per International Conference on Harmonization guideline (ICH) for accuracy, precision, robustness, and specificity, limit of detection and limit of quantitation. Statistical analysis of results obtained proves that the method is repeatable and selective for estimation of both the drugs. As the method could effectively separate the drug from its degradation products, it can be employed as a stability indicating method.