133A STABILITY-INDICATING HIGH PERFORMANCE LIQUID CHROMATOGRAPHIC METHOD FOR SEPARATION AND QUANTIFICATION OF IMPURITIES IN ETHINYLESTRADIOL AND GESTODENE TABLETSA new gradient reverse phase high performance liquid chromatography method has been developed for quantitative determination of related substances of Ethinyl estradiol (EE) and Gestodene (MC) in pharmaceutical dosage forms. Chromatographic separation achieved on a column L11, Phenyl 250 mm x 4.6 mm; 5 μm with 0.1% Ortho phosphoric acid (OPA) solution as mobile phase-A and Acetonitrile and 0.1% OPA (9:1) as mobile phase–B at a flow rate of 1.0 mL min-1. Diluent as water and acetonitrile of ratio 50:50 v/v with detection at 210 nm and 240 nm. The injection volume was 100 μL and a gradient program with run time of 65 minutes. The developed method validated according to ICH guideline with the parameters specificity, forced degradation (with stress conditions of acid, base, oxidative hydrolysis, thermal and photolytic degradation), limit of detection and limit of quantification, linearity, precision, intermediate precision, accuracy, robustness and ruggedness. From all validation parameters results the method proved as specific, stability indicating, precise, accurate, robust and rugged method.24kishore@gmail.comResearch712017Ethinyl estradiol, Gestodene, Validation, HPLC.I Kishore Kumar,P Jayaprakash,V Sivannarayana Reddy,J. SriramuluI Kishore Kumar,P Jayaprakash,V Sivannarayana Reddy,J. Sriramulu