Development of an HPLC Method for Simultaneous Quantification of Rosmarinic Acid, Sinensetin in Herba Orthosiphonis spiralis

The purpose of this study was to develop an HPLC method for the simultaneous quantification of rosmarinic acid and sinensetin in Herba Orthosiphonis spiralis. The chromatographic separation was performed on an Ascentis®C8 column (250 × 4.6 mm, 5 µm) using a gradient elution mode with acetonitrile and water containing 0.1% formic acid as mobile phase. The flow rate was maintained at 0.6 mL/min. The injection volume was 10 mL. The column temperature was set at 40 °C. Analytes were detected by a PDA detector at a wavelength of 329 nm. The method was validated for specificity, system suitability, linearity, accuracy, precision, detection limit, and quantitation limit according to ICH and AOAC. The results of validation showed that the method met all the acceptance criteria and was suitable for simultaneous quantification of rosmarinic acid and sinensetin in Herba Orthosiphonis spiralis.