Green HPLC-Fluorescence Method for Tamsulosin and Solifenacin in Dosage Forms Optimized by Box-Behnken Design

An eco-friendly and precise HPLC with fluorescence detection has been established for the concurrent assay of tamsulosin and solifenacin (TAM/SOL) mixture. This strategy provides the high separation power of chromatography combined with the high sensitivity of fluorescence measurements. Box-Behnken design was used to optimize the chromatographic method. A good separation was attained on a C₁₈ column at a 1.02-mL min^-1 flow rate. For TAM and SOL, the retention times were 1.71 and 3.52, respectively. The measurements were carried out using a fluorescence detector at 225 nm for excitation and 330 for emission. TAM and SOL had linear calibration curves at concentration ranges of 0.1-1.5 and 1.5-22.5 μg mL^-1, respectively. The limits of detection were 0.02 and 0.41, whereas the limits of quantification were 0.07 and 1.23 μg mL^-1 for TAM and SOL, respectively. The proposed technique was used to determine TAM and SOL in their dosage form with a %recovery of 100.50 and 100.39, respectively. The proposed method was the only method used to assess the combined tablets content uniformity. Two greenness evaluation tools, GAPI and AGREE, were used to assess the greenness of the proposed HPLC method and the results showed a remarkable compliance with the green chemistry principles.