Development of Chromatographic Method for The Simultaneous Estimation of Solifenacin and Mirabegron in Combination Tablet Dosage form

A simple, accurate, and precise reverse-phase high-performance liquid chromatographic (RP-HPLC) method was developed and validated for the simultaneous estimation of Solifenacin Succinate and Mirabegron in a combined tablet dosage form. The method employed a C18 column with a mobile phase consisting of acetonitrile and phosphate buffer (pH adjusted to 3.5 with orthophosphoric acid) in a 60:40 v/v ratio. The flow rate was maintained at 1.0 mL/min and detection was carried out at 220 nm. The retention times for Solifenacin and Mirabegron were found to be approximately 3.8 and 6.2 minutes, respectively. The method was validated as per ICH guidelines and showed good linearity (r² > 0.999), precision (RSD < 2%), accuracy (recoveries within 98-102%), and robustness. This method can be successfully applied for routine quality control and stability studies of Solifenacin and Mirabegron in combined pharmaceutical formulations.