Green validated HPTLC and HPLC methods for determination of ephedrine hydrochloride and naphazoline nitrate in the presence of methylparaben, in their pure forms and pharmaceutical formulation

Abstract

Green validated high-performance thin-layer chromatography (HPTLC) and high-performance liquid chromatography (HPLC) methods were established for resolving ephedrine hydrochloride (EPH), naphazoline nitrate (NAP), and methylparaben (MET) mixture. Method A is HPTLC–densitometric one that depends on their separation and quantitation on HPTLC silica gel 60 F254 plates, using ethyl acetate:ethanol:triethylamine (8:2:0.2, v/v) as a developing system followed by densitometric measurement at 220 nm. Method B includes HPLC separation and quantification of the introduced mixture on C18 column using a mobile phase consisting of water:ethanol:acetonitrile (80:20:2, v/v) flowing at 1 mL/min. The separated peaks were detected at 220 nm. International Conference on Harmonization (ICH) guidance for method validation was obeyed; EPH and NAP can be determined in the concentration ranges of 2–16 μg/band and 0.4–1.8 μg/band, respectively, using HPTLC method and 5–30 μg/mL and 2–30 μg/mL, respectively, using HPLC method with correlation coefficients > 0.9995. The methods were proven to be accurate, selective, and repeatable for the determination of the two drugs, and can be used for their estimation to check their purity in powder forms and quantifying them in pharmaceutical formulation. The greenness of the procedures was assessed to make sure that they have no adverse environmental effects.