Simultaneous Quantification RP-HPLC Method Development and Validation for Atorvastatin and Tadalafil in Bulk Form

Background: Tadalafil and Atorvastatin together have been shown to significantly enhance hemodynamics and sexual performance in middle-aged and older patients with hyperlipidemia. Despite of the number of techniques for estimating tadalafil and atorvastatin calcium, the Reverse Phase-High Performance Liquid Chromatography (RP-HPLC) technique for simultaneous determination of Atorvastatin calcium and Tadalafil has not yet been disclosed.

Purpose: A sensitive, simple, rapid, reverse phase high pressure liquid chromatography (RP-HPLC) method has been developed and validated for the simultaneous estimation of Tadalafil and Atorvastatin in bulk form.

Methods: The method was carried out utilizing the C-18 column (Sapphirus, 5 x 250 mm) and mobile phase at 1 ml/min flow rate. 0.05M phosphate buffer (30:70 v/v gradient mode) and acetonitrile were the ideal mobile phase conditions. The pH was changed with glacial acetic acid to 4.0.

Results: Tadalafil and Atorvastatin had retention times of 3.517 and 4.117, respectively, according to data collected concurrently. The linearity range for Atorvastatin and Tadalafil (15 µg/ml to 90 µg/ml) was established using an external standard calibration method. It was calculated that the recovery rate ranges from 98.09 to 101.44 percent, and it was discovered that all values fall within this range. The limits of detection for Atorvastatin and Tadalafil are 0.318 µg/ml and 0.672 µg/ml, respectively.

Conclusion: The method was found to be robust, durable, accurate and linear for validated parameters. The % RSD observed for flow rate, wavelength, and analyst variation was found to be below 2, which was considered acceptable in the robustness investigation.