A novel fluorimetric method for determination of pseudoephedrine hydrochloride in pharmaceutical formulations and blood serum

Abstract

An inexpensive, simple, highly sensitive, and rapid fluorimetric method was developed for the analysis ofpseudoephedrine hydrochloride at trace levels. The method is based on the recovery of fluorescence of Rh6G dye due tothe interaction of pseudoephedrine hydrochloride with Rh6G-Au NPs complex, which results in the release of Rh6G fromthe complex and halting fluorescence resonance energy transfer between Rh6G and Au NPs. The intensity of fluorescencewas directly proportional to the concentration of the analyte, which was used for its determination. Experimental factorswere optimized by response-surface methodology. Under optimum conditions, the calibration curve was linear over therange of 15–150 ng $mL^{-1}$and the limit of detection (LOD) was 10 ng $mL^{-1}$. Percent relative standard deviation (n=5) for determination of 50 ng $mL^{-1}$ pseudoephedrine hydrochloride was 3.74%. The method was successfully used fordetermining the analyte in human blood serum and in pharmaceutical formulations. The possible mechanistic descriptionof the analytical reaction was proposed on the basis of TEM, FT-IR, and fluorescence spectra analysis.