DETERMINATION OF PARACETAMOL, METHYL PARAHYDROXYBENZOATE, ETHYL PARAHYDROXYBENZOATE, AND PROPYL PARAHYDROXYBENZOATE IN MEDICINAL SUSPENSION AND TABLETS BY RPLC/UV-DAD

摘要

This paper presents a new reversed-phase liquid chromalographic (RPLC) method with ultraviolet absorbance diode-array detection (UV-DAD) for simultaneous determination of paracetamol, methyl parahydroxybenzoale, propyl parahydroxybenzoate, and ethyl parahydroxybenzoale in commercial medicinal oral suspension and tablets. The chromalographic separation is achieved with acetonitrile, telrahydrofuran, and water in a ratio of 21:13:66 (v/v/v) adjusted to pH 3 with formic acid as the mobile phase, a Lichrosorb RP8 (150mmx 4.6mm, 5 mum) column, and UV detection at 249 nm. The linear range of determination for paracetamol, methyl parahydroxybenzoate, propyl parahydroxybenzoate, and ethyl parahydroxybenzoate were 25-160 mug/mL, 20-128 ug/mL, 5-40mug/mL, and 5-32ug/mL, respectively. The correlation coefficients are >=0.9997 for each analyle. The mean percent relative standard deviation values for intra- and inlerday precision studies are < 1% in each case. The applicability of the method was evaluated in commercial dosage forms analysis.