Development and validation of stability-indicating RP-HPLC method for simultaneous estimation of clomiphene citrate and co-enzyme Q10 in bulk and pharmaceutical dose.

Clomiphene citrate (CLO) and co-enzyme Q10 (Q10) are "ovulatory stimulants" used to treat female infertility and CLO-resistant Polycystic Ovary Syndrome (PCOS). The study aimed to create a unique and well-validated stability-indicating RP-HPLC method for quantifying CLO and Q10 in bulk and tablet formulation, supported by UV analysis. The λ max values of CLO and Q10 were determined at 293 nm and 273 nm, respectively. The chromatographic separation was achieved on a Waters XBridge phenyl 5 μm column (4.6 × 250 mm) using an acetonitrile: tetrahydrofuran (80:20 v/v) with 0.5% triethylamine as a mobile phase at a flow rate of 0.5 mL/min with photodiode array detector at 279 nm (isobestic point). Resveratrol (RES) served as an internal standard (ISTD), with retention durations of 6.504, 9.319 and 5.831 minutes for CLO, Q10 and RES, respectively. Calibration curves were linear (R2 = 0.9987 for CLO and 0.9993 for Q10) and %RSD values for all validation parameters were below 2%, confirming precision and accurate. Forced degradation studies through various stress conditions, assessed the method's stability-indicating nature by exhibiting clear separation of degradation products from the analytes and degradation levels within ICH limits (≤ 20%). The validated method was found to be reliable, specific, and applicable for routine analysis in quality control.