SIMULTANEOUS ESTIMATION OF MEFENAMIC ACID AND HYOSCINE-N-BUTYL BROMIDE BY NOVEL RP-HPLC METHOD IN BULK AND PHARMACEUTICAL DOSAGE FORM

A novel, precise, accurate, rapid and cost effective isocratic reverse-phase high performance liquid chromatographic (RP-HPLC) method was developed, optimized and subsequently validated for the estimation of Mefenamic acid and Hyoscine-N-Butyl bromide in the bulk and pharmaceutical dosage form. Separation was achieved on Inertsil ODS-3 column (250 × 4.6 mm, 5 μm) on Agilent HPLC 1260 system using potassium phosphate buffer (5 mM, pH 3.0): acetonitrile (25:75 v/v) as mobile phase and flow rate of 1 mL/min at 210.0 nm. The method was validated according to USP category I requirements. The system suitability shows the response with retention time, theoretical plate, tailing factor and peak area for both the drugs. Mefenamic acid and Hyoscine-N-butyl bromide marketed drug products were obtained from a drug distributor and assayed for potency using the validated method. Validation acceptance criteria were met in all cases. The linearity ranges were obtained 10-30 µg/mL for MFA and 20-60 µg/mL for HBB with retention times (Rt) 9.3 and 5.27 min respectively, and the linearity was r2 > 0.999. The method was determined to be specific and robust. Both accuracy (98.95-99.12%) and precision (0.808-1.549%) were established across the analytical range for low, intermediate and high QC concentrations. Method applicability was demonstrated by analyzing marketed product (Hyocimax MF) of MFA and HBB, in which results showed potency >98%. The developed method was successfully used for the quality assessment of marketed drug products and assesses the product quality of novel dosage forms. Key Words: Mefenamic acid (MFA), Hyoscine-N-butyl bromide (HBB), RP-HPLC, Method Validation