Simultaneous estimation of paracetamol and domperidone in tablets by reverse phase HPLC method

A simple, fast, precise and accurate liquid chromatographic method was developed for the simultaneous estimation of paracetamol and domperidone in combined dosage forms. This combination is used for antiemetic and pain associated with gastrointestinal disorders. Drugs are chromatographed on a reverse phase Kromasil C18 column using a mobile phase, 20 mM phosphate buffer (pH 7.0±0.1) and acetonitrile in the ratio of 60:40%v/v. Diclofenac potassium was used as an internal standard. The retention time of paracetamol, domperidone, and diclofenac potassium was 2.94, 8.30, 5.67 min, respectively. The validation of the proposed method was also carried out. The method was found to be linear (r>0.99), precise (%RSD: 0.49% for paracetamol and 0.89% for domperidone), accurate (overall average recovery yields: paracetamol 99.1% and domperidone 98.36%) and selective. Due to its simplicity and accuracy the proposed method can be used for routine quality control analysis of these drugs in combined dosage form.