Formulation.

ABSTRACTA new precise, accurate, robust and stability indicating high-performance liquid chromatographic method has been developed and validated for the simultaneous estimation of domperidone (DOM) and esomeprazole (ESO) in their pharmaceutical formulation. The proposed method carried out on Waters Symmetry C18 column (250 mm x 4.6 mm, 5.0 µm particle size) using an isocratic elution technique at a column temperature of 30 ?C. The mobile phase was a mixture of 0.01M sodium acetate buffer: methanol (45:55 v/v) and it was adjusted to pH 4.5 using glacial acetic acid with a flow rate of 1 mL/min and an injection volume of 20 µL. The retention times were 3.7 and 5.0 min with UV detection at 290 nm for DOM and ESO, respectively. The proposed method was linear over the concentration ranges of 0.04-60.0 and 0.08-120.0 µg/mL for DOM and ESO, respectively. Limit of detection and limit of quantitation values were 0.48 and 1.44 µg/mL for DOM and 0.47 and 1.43 µg/mL for ESO, respectively. The method also exhibited good levels of recovery from 100.23% to 101.59% for DOM and from 99.74% to 101.57% for ESO. From the validation study, it was found that the method was specific, rapid, accurate and reproducible. The high percentage of recovery and low relative standard deviation confirm the suitability of the method for routine pharmaceutical analysis of both drugs separately or in their combined dosage form. Keywords: HPLC; Esomeprazole; Domperidone; Validation; Formulation.