Determination of tadalafil in pharmaceutical preparation by HPLC using monolithic silica column

The simple, reliable and reproducible HPLC and extraction methods were developed for the analysis of tadalafil in pharmaceutical preparation. The column used was monolithic silica column, Chromolith Performance RP-18e (100 mm × 4.6 mm, i.d.). The mobile phase used was phosphate buffer (100 mM, pH 3.0)-acetonitrile (80:20, v/v) at the flow rate of 5 mL min−1 with UV detection at 230 nm at ambient temperature. Extraction of tadalafil from tablet was carried out using methanol. Linearity was observed in the concentration range from 100 to 5000 ng mL−1 for tadalafil with a correlation coefficient (R2) 0.9999 and 100 ng mL−1 as the limit of detection. The values of linearity range, correlation coefficient (R2) and limit of detection were 50-5000 ng mL−1, 0.9999-50 ng mL−1, respectively for sildenafil. Parameters of validation prove the precision of the method and its applicability for the determination of tadalafil in pharmaceutical tablet formulation. The method is suitable for high throughput analysis of the drug.