Development and Validation of Stability Indicating Thin-Layer Chromatography Method for Simultaneous Estimation of Benidipine Hydrochloride and Telmisartan

For the simultaneous estimation of Benidipine hydrochloride (BEN) and Telmisartan (TEL) in combined pharmaceutical dosage form, a stability-indicating high-performance thin-layer chromatography (HPTLC) method has been developed and validated. It involves the use of HPTLC plates pre-coated with silica gel 60F(254) and a mobile phase comprising of Methanol: Acetonitrile (1:9 v/v). The measurements of both drugs were performed at 237 nm. The drugs were subjected to acid-alkali hydrolysis, photolytic, thermal, and oxidation degradation. The linearity of BEN was found to be between 200-1000 ng/band (R-2 = 0.9917), while for TEL, linearity was found to be between 2000 and 10000 ng/band (R-2 = 0.9979). The limit of detection and limit of quantitation were found to be 3.28 and 9.94 ng/spot for BEN and 158.79 and 481.17 ng/spot for TEL. The % relative standard deviation of the precision study was determined to be less than 2%. Various system suitability parameters were determined. The Rf values of BEN and TEL were found to be 0.890 +/- 0.0105 and 0.173 +/- 0.0151, respectively. The resolution between BEN and TEL peak were found to be 4.48 and capacity factors were found to be 0.21 and 0.74 for BEN and TEL, respectively.