Analytical Method Development and Validation of an RP-HPLC Method for Stability-Indicating Determination of Idelalisib

This study aimed to develop and validate a stability-indicating reverse-phase high-performance liquid chromatography (RP-HPLC) method for the quantitative analysis of idelalisib, a potent phosphoinositide 3-kinase delta (PI3K delta) inhibitor, in pharmaceutical formulations. An RP-HPLC method was developed using an Agilent C18 column (5 mu m, 4.6 x 250 mm) and a mobile phase consisting of a mixture of methanol/0.05% ortho-phosphoric acid (75:25) at a flow rate of 0.7 ml/min with UV detection at 269 nm. Forced degradation studies were conducted to evaluate the method's stability-indicating capability. Validation parameters-including linearity, precision, accuracy, specificity, robustness, and system suitability-were assessed according to ICH guidelines. The developed RP-HPLC method demonstrated excellent linearity over a wide concentration range, with a correlation coefficient (r) of >0.999 with respect to the peak area in a concentration range of 5-250 gmL-1. The method exhibited high precision, with relative standard deviations (RSD) for repeatability and intermediate precision well within acceptable limits. Accuracy was confirmed through recovery studies, and the RSD ranged from 0.13% to 0.94%. Forced degradation studies revealed the method's ability to separate and quantify idelalisib from its degradation products. The actual percentage degradation ranged between 0.16% to 6.29%. The limits of detection and quantification were 0.066 mu g/ml and 0.2 mu g/ml, respectively. Precision was established whereby the mean interday and intraday RSD were 0.58% and 0.45%, respectively. The method's robustness was confirmed through deliberate variations in method parameters, which had negligible effects on the assay results (.4% RSD). The method was applied to commercially available tablets, yielding an average (SD) idelalisib recovery of 101.45% (0.08) with a % RSD of 0.08%. The developed RP-HPLC method is a stability-indicating assay for idelalisib with excellent specificity, linearity, precision, and accuracy. It is suitable for routine analysis of idelalisib in pharmaceutical formulations and can be employed for stability studies and quality control purposes, ensuring the drug's quality and efficacy throughout its shelf life.