Utility of micellar liquid chromatography as an analytical tool for the estimation of three binary antibiotic mixtures. Application to biological fluids

Abstract

A reliable and sensitive micelle based liquid chromatography (MLC) was developed aiming to simultaneously estimate three binary antibiotic mixtures namely: cefixime (CFX) in combination with either linezolid (LNZ) (mixture Ι) or levofloxacin hemihydrate (LEV) (mixture II), and nifuroxazide (NX) with drotaverine HCl (DV) (mixture IΙI). All mixtures were separated using a micellar mobile phase prepared in 0.02 M phosphoric acid and consisting of an anionic surfactant; sodium dodecyl sulphate, triethylamine (0.3%), n-propanol, adjusted to pH 2.5 (for mixtures Ι and ΙΙ) or pH 5 for mixture ΙΙΙ with detection wavelengths of 254, 295, and 210 nm for the three mixtures respectively. Separation of the first two mixtures was conducted using a C18 column, while the last mixture was separated using a C18 monolithic column. Drugs in mixture I were rectilinear at (1.0–320.0 µg/mL) and (0.5–320.0 µg/mL) for CFX and LNZ, respectively with corresponding detection limits of 0.3269 and 0.0512 µg/mL and quantitation limits of 0.9906 and 0.1552 µg/mL, while pharmaceutical agents in mixture II showed linearity over the ranges of (0.125–80.0 µg/mL) and (0.25–160.0 µg/mL) for CFX and LEV, respectively with corresponding detection limits of 0.0154 and 0.026 µg/mL and quantitation limits of 0.0465 and 0.0789 µg/mL. Whereas linearity ranges of the analytes in mixture ΙΙΙ were 0.5–400.0 µg/mL and 2.0–400.0 µg/mL for NX and DV respectively with corresponding detection limits of 0.1822 and 0.2631 µg/mL and quantitation limits of 0.5522 and 0.7974 µg/mL. The proposed method was thoroughly validated; besides it was applied to estimate the concerned analytes in their dosage forms. The results obtained from the developed method and the reference methods were in accordance. The proposed method was further extended to determine drugs of mixtures Ι and ΙΙ in spiked human plasma without any extraction steps with high recovery percentages.