Stability Indicating Fast LC Method for Determination of Tadalafil and its Intermediates in Bulk and Pharmaceutical Formulation

Fast LC method has been developed and subsequently validated for the determination of Tadalafil and its intermediates in bulk and pharmaceutical formulation. Separation was achieved in Gradient mode using Peerless HT gold, C18, 50×4.6 mm, 1.8 μm column with mobile phase A containing Potassium Dihydrogen Phosphate buffer (pH adjusted to 3.0±0.05 with Orthophosphoric acid) and mobile phase B containing Methanol 100% at different time intervals as eluent at a flow rate 0.8 ml/min. UV detection was performed at 220 nm. The method is simple, rapid, selective and stability indicating. The described method is linear over a range of 12.5748 μg/mL to 76.4548 μg/mL. The method precision for the determination of assay was below 2.0% RSD. The Percentage recoveries of Active Pharmaceutical Ingredient (API) from dosage forms ranged from 101.0 to 102.1 for all available strengths of Tadalafil in market. LOD and LOQ of all related impurities of Tadalafil was established and ranged from 0.006 μg/ml-0.011 μg/ml for LOD and 0.018 μg/ml-0.033 μg/ml for LOQ. The method is useful in the quality control of bulk manufacturing and also in pharmaceutical formulations.