Simultaneous Quantification of Drospirenone, Ethinyl Estradiol and Levomefolate by Stability Indicating RP-HPLC Method

A new sensitive, selective, precise and accurate stability indicating reverse phase high performance liquid chromatographic method has been developed for the simultaneous quantification of drospirenone, ethinyl estradiol and levomefolate in bulk and combined tablet dosage form. Separation and analysis of drospirenone, ethinyl estradiol and levomefolate was achieved on Waters C18 (5 μm, 250 mm × 4.6 mm) column using 0.1% H3PO4, methanol and acetonitrile in the ratio of 60:20:20 (v/v/v) as mobile phase at 27°C. The flow rate was 1.0 mL/min. The effluents were monitored with detector set at 245 nm. The method validation was done with regard to the guidelines by the International Conference on Harmonization and US Food and Drug Administration. All the validation characteristics are within the acceptance criteria. The studied drugs were subjected to acid, alkali and neutral hydrolysis, hydrogen peroxide oxidation, thermal degradation, and photo (sunlight) degradation. The peaks of degradation products were well resolved from the peaks of three analytes (drospirenone, ethinyl estradiol and levomefolate). Hence, the developed and validated liquid chromatographic method is able to quantify the drospirenone, ethinyl estradiol and levomefolate in the presence of degradation products.