SIMULTANEOUS DETERMINATION OF GUAIFENESIN AND EPHEDRINE HCl BINARY MIXTURE IN SYRUP DOSAGE FORMS AND HUMAN PLASMA BY USING RP-HPLC-DAD

A new and simple quantitative analysis method for the determination of Guaifenesin (G) and Ephedrine HCl (E) binary mixtures was developed and validated. Phosphate buffer-methanol combination (60:40, v/v) was chosen as an isocratic mobile phase and adjusted to pH 3 for this liquid chromatographic method which was developed for the simultaneous analysis of G and E combination. The method was observed in concentration ranges of 30-100 mu gmL(-1) (G) and 15-50 mu gmL(-1)(E). The total run time for detections performed at 212nm was less than 10min. The reverse phase-high performance liquid chromotography (RP-HPLC) method developed in this study was successfully applied to pharmaceutical preparations in syrup dosage form and human plasma samples (in vitro) without liquid-liquid extraction. And the statistical comparison of this method was performed both in pharmaceutical preparations and human plasma samples