A Validated RP-HPLC Method for Simultaneous Estimation of Benidipine and Telmisartan in Bulk and Tablet Dosage Form

Background: In this work, a novel, simple and accurate reverse phase high-performance liquid chromatographic method with UV detection is presented for the simultaneous estimation of Benidipineand Telmisartan in API and marketed formulations. Objective: To develop and validate this method in accordance to regulatory guidelines i.e. ICH Q2B-R1 for analytical parameters. Methods: In RP-HPLC the separation was achieved using a Xbridge C18 (250x 4.6 i.d; 5µm) column with isocratic elution using a mobile phase consisting of methanol: acetonitrile (80:20v/v/ with 0.1% v/v TEA) adjusted to pH 5.2 with glacial acetic acid at 1mL/min flow for 10min. Benidipine and Telmisartan, were detected at dual wavelength at 237 and 297nm with retention time (Rt) 6.891 and 8.997 minutes respectively. Results: Our new methods (RP-HPLC) were found to (r2>0.999) for both Benidipine and Telmisartan. The developed methods are highly selective, precise and reproducible with %RSD < 2%, Moreover the methods are accurate with recovery more than 99% in both methods. Conclusion: The RP-HPLC method results are efficient, simple and easy. These highly sensitive methods were successfully applied for assay determination of both Benidipine and Telmisartan at fixed dose combination.