Development and Validation of A Robust RP-HPLC Method For Simultaneous Estimation of Telmisartan and Cilnidipine In Bulk and Tablet Dosage Form

ABSTRACTA simple, accurate, precise, and cost-effective reversed-phase high-performance liquid chromatography (RP-HPLC) method has been developed and validated for the simultaneous estimation of Telmisartan and Cilnidipine in bulk and marketed tablet dosage form. Chromatographic separation was achieved using an Agilent C18 column (250mm × 4.6mm, 5 ?m) with a mobile phase consisting of Acetonitrile and phosphate buffer (pH 3.0) in a 90:10 v/v ratio, at a flow rate of 1.0 mL/min and detection wavelength of 254 nm. Method validation followed ICH Q2 (R1) guidelines for system suitability, linearity, accuracy, precision, robustness, LOD, and LOQ. The method showed linearity over the range of 40–240 ?g/mL for Telmisartan and 10–60 ?g/mL for Cilnidipine, with correlation coefficients (R²) of 0.9998 for both drugs. The method was found to be accurate, precise (%RSD < 2%), robust, and suitable for routine quality control analysis in pharmaceutical formulations. Keywords: Telmisartan, Cilnidipine, RP-HPLC, Method Validation, ICH Q2(R1), Fixed-Dose Combination