DEVELOPMENT AND VALIDATION OF RP-HPLC METHOD FOR SIMULTANEOUS ESTIMATION OF AZELNIDIPINE AND TELMISARTAN IN PHARMACEUTICAL DOSAGE FORM

Aim: To develop and validate a simple, rapid and accurate RP-HPLC method for the simultaneous estimation of Azelnidipine and Telmisartan in pharmaceutical dosage forms. Methodology: Separation was achieved on Phenomenex Luna C18 column (250 mm × 4.6 mm, 5 μm) using an isocratic mobile phase of Methanol: Phosphate Buffer (37:63 % v/v, pH 4.2) at 1.0 mL/min, detected at 260 nm via PDA. Acetonitrile was entirely replaced by methanol, reducing cost and toxicity versus ACN-based methods (60–80% v/v). Detection at 260 nm was selected over 215–242 nm used in prior methods for superior signal-to-noise ratio. pH 4.2 suppresses ionization of Telmisartan carboxylate group (pKa ≈4.1), ensuring sharp peak symmetry. The method was validated as per ICH Q2(R1) guidelines. Results: AZL AND TEL are eluted at 2.13 and 3.69 min respectively. Linearity was found at concentration ranges of 20-60μg/ml for AZL and 10-30μg/ml for TEL. The recoveries obtained were 98‒102% for AZL, and 99.62 – 99.88% for TEL. Conclusion: The method was validated according to ICH guidelines for accuracy, precision, linearity, specificity, limit of detection, limit of quantification and robustness. This fully validated, eco-friendly, isocratic RP-HPLC method with superior resolution and no complex sample pre-treatment is superior alternative for routine quality control of the AZL-TEL.