RESUMO
The development and validation of a reversed-phase liquid chromatographic (LC) method for the determination of cetirizine dihydrochloride in oral formulations are described. An isocratic LC analysis was performed on a reversed-phase C18 column (250 x 4.6 mm id, 5 microm particle size). The mobile phase was 1% orthophosphoric acid solution, pH 3.0-acetonitrile (60 + 40, v/v), pumped at a constant flow rate of 1.0 mL/min. Measurements were made at a wavelength of 232 nm. The calibration curves were linear over the range of 10-30 microg/mL (r2 = 0.9999). The relative standard deviation (RSD) values for intraday precision were 0.94 and 1.43% for tablets and compounded capsules, respectively. The RSD values for interday precision were 0.13 and 0.82% for tablets and compounded capsules, respectively. Recoveries ranged from 97.7 to 101.8% for tablets and from 98.4 to 102% for compounded capsules. No interferences from the excipients were observed. Because of its simplicity and accuracy, the method is suitable for routine quality-control analysis for cetirizine in tablets and compounded capsules.