Determination of tadalafil in pure powder and tablet dosage form by high-performance liquid chromatography

A simple and accurate method to determine tadalafil (TAD) in pure powder and tablet dosage form was developed and validated using HPLC. The separation was achieved on an Xterra RP18 column (150 x 4.6 mm id, 3.5 microm) in the isocratic mode using buffer-acetonitrile (70 + 30, v/v), adjusted to pH 7.00 +/- 0.05 with triethylamine as the mobile phase at a flow rate of 1.0 mL/min. The photodiode array detector was set at 225 nm. Quantification was achieved over the concentration range of 50.7-152.10 microg/mL with mean recovery of 100.26 +/- 0.75%. The method was validated and found to be simple, accurate, precise, and specific. The method was successfully applied for the determination of TAD in pure powder and tablet dosage form without interference from common excipients or degradation products.