DEVELOPMENT AND VALIDATION OF STABILITY INDICATING RP-HPLC METHOD FOR ESTIMATION OF BILASTINE AND MONTELUKAST IN BULK AND DOSAGE FORM USING QUALITY BY DESIGN (QBD) APPROACH

A simple, precise, rapid and accurate stability indicating RP-HPLC method for estimation of Bilastine and Montelukast in bulk and dosage form using quality by design (QBD) approach. An Kromasil C18, 250 mm X 4.6 mm dimension with 5µm particle size, the mobile phase, consisting of 0.05 % OPA and Methanol in the ratio of 50:50 v/v, prepare mixture of 0.1% OPA: Acetonitrile: methanol in the ratio of 20:40:40 % v/v/v used as a diluent for preparation of solution. The flow rate was 1.0 ml/min and the effluents were monitored at 225 nm. The retention time was 2.66 min for Bilastine and 8.97 min for Montelukast. The RP-HPLC method optimization study and statistical analysis were performed using Design Expert® software. The mobile phase composition (X1) and flow rate (X2) were selected as independent variables and retention time, asymmetry and Theoretical plates were selected as dependent variables. The linearity for this method was found to be in the range of 80-120 μg/ml and 40-60μg/ml for Bilastine and Montelukast. This Robust method was capable to recover accurately and precisely from 80 %, 100 % and 120 % level of target concentration. Forced degradation studies were performed under different conditions like Acidic, Basic, oxidation, Photo and Thermal degradation. Considerable Degradation was found in Acidic and basic degradation. The results of the study showed that the proposed stability indicating RP-HPLC method is simple, rapid, precise and accurate, which is useful for the routine determination of Bilastine and Montelukast in pharmaceutical dosage form.