Optimized and validated spectrophotometric methods for the determination of roxatidine acetate hydrochloride in drug formulations using 2,3-dichloro-5,6-dicyano-1,4-benzoquinone and p-chloranilic acid

Two simple and sensitive spectrophotometric procedures are proposed for the determination of roxatidine in pure form and in tablets. Both methods are based on the charge transfer complexation reaction of the drug with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) or p-chloranilic acid resulting in colored products. In both cases, the absorbance measurement was made at 530 nm. Beer's law was obeyed in the concentration ranges 5-65 and 10-260 μg mL-1 with DDQ and p-chloranilic acid, respectively. A series of variables were studied to optimize the reaction conditions. No interference was observed from the common excipients present in the formulations. The described methods were applied successfully for the analysis of roxatidine in pharmaceutical preparations. Statistical comparison of the results with those from our UV reference method shows excellent agreement. Both methods are validated statistically and do differ significantly in accuracy. © 2005 Pleiades Publishing, Inc.