Simultaneous determination of Guaifenesin, codeine phosphate, phenylephrine hydrochloride, and sodium benzoate in syrup pharmaceutical form by RP-HPLC

Abstract

This work describes the development of the RP-HPLC method for the simultaneous estimation of Guaifenesin, codeine phosphate, phenylephrine, and sodium benzoate. This method separates Guaifenesin, codeine phosphate, phenylephrine, and sodium benzoate nicely. This RP-HPLC method uses the Shimadzu HPLC instrument with Chromegabond WR C18 column  5 μm 120 A  30 cm * 3.9 mm. The mobile phase is a mixture of 1% o-phosphoric acid, methanol: acetonitrile (80 : 10: 10), and the pH was adjusted to 3.1. Isocratic elution mode was used with 1 ml/min as the flow rate. The detection for all compounds is carried out at 254 nm. The retention time of Guaifenesin, codeine phosphate, phenylephrine, and sodium benzoate was 14.11, 5.75, 3.9, and 20.52, respectively. The method has been validated concerning accuracy, linearity, and precision. This method is simple, accurate, and reproducible. This validated method was used to estimate these drugs in syrup pharmaceutical form.