RP HPLC Method for Estimation of Dapoxetine Hydrochloride and Tadalafil Hydrochloride as API and in Tablet Dosage Form

The article, for the first time, reports High performance liquid chromatography [HPLC] method for estimation of Dapoxetine hydrochloride [DAP] and Tadalafil hydrochloride [TAD]. The analytical method was developed for both the drugs as API and for tablet dosage form. The separation of two drugs was achieved on High quality octa decyl silane [C18 250x 4mm i.d] 5μ column. The mobile phase consists of Acetonitrile and phosphate buffer in the ratio of 45:55. Mobile phase flow rate adjusted at 1 ml/min and pH at 4.2 using ortho phosphoric acid. The detection was carried out at a wavelength 254 nm. Retention time was found 4.46 and 10.11 min respectively for TAD and DAP. The method was validated for system suitability, linearity, accuracy, and precision and solution stability as per ICH guidelines. Linearity was obeyed in the range of 8-48 mg/ml and 24- 144 mg/ml with correlation coefficient of 0.997 and 0.998 for TAD and DAP respectively. Recovery studies were found within prescribed limits that was 98.83 for TAD and 98.93 for DAP respectively. Detection and quantification limit were found to be 0.225mg/ml and 0.682mg/ml for TAD and 0.163 mg/ml and 0.494mg/ml for DAP respectively which expresses higher sensitivity of the method. Assay results were found to be 98.52 % and 98.26 % in generic brand whereas 99.03 % and 98.11 in other brand for TAD and DAP respectively.