Stability Indicating RP-HPLC Method Development and Validation for Simultaneous Estimation of Silodosin and Tadalafil in Synthetic Mixture

This study developed an RP-HPLC method to simultaneously determine Silodosin and Tadalafil. Using a Thermo BDS C18 column with a mobile phase of dipotassium hydrogen phosphate buffer and acetonitrile (60:40), the method achieved retention times of 2.905 minutes for Silodosin and 5.082 minutes for Tadalafil. The method exhibited excellent linearity with a correlation coefficient of 0.999 for both drugs, with Silodosin ranging from 1.6-200µg/mL and Tadalafil from 1-125µg/mL. The accuracy was between 99.24% and 100.97% for Silodosin and 99.92% and 100.13% for Tadalafil. The limits of detection were 0.40μg/mL for Silodosin and 0.20μg/mL for Tadalafil, while the limits of quantification were 1.21μg/mL and 0.63μg/mL, respectively. This method is precise and accurate, making it suitable for routine analysis of these drugs.