Determination of hyoscine n-butyl-bromide, lidocaine hydrochloride, and paracetamol in injection forms using solid-phase extraction, high-performanceliquid chromatography, and UV-Vis spectrophotometry

A solid phase extraction procedure using strong cation exchange (SCX, benze nesulfonic acid) cartridges followed by a reversed-phase HPLC assay was app lied to the analysis of hyoscine n-butylbromide and lidocaine hydrochloride in injection forms. The chromatographic separation was performed on a BDS C-18 column. The mobile phase consisted of a mixture of acetonitrile : ammo nium acetate 0.2M, (30:70, v/v) pumped at a flow rate 1.2 mL/min. The UV de tector was operated at 254 nm. A W-Vis spectrophotometric method was also d eveloped for the determination of paracetamol in the injection forms. The m ethod consists of subsequent dilution of the injection forms and measure of the absorbance value at 242.7 nm. Relative standard deviation was less tha n 0.95% for HPLC and less than 0.78% for the spectrophotometric method. Det ection limits were 1.05, 0.96 and 0.67 mu g/mL for hyoscine n-butylbromide, lidocaine hydrochloride and paracetamol, respectively.