Simultaneous determination of hydroxyzine hydrochloride and benzyl alcohol in injection solutions by high-performance liquid chromatography.

A stability-indicating, high-performance liquid chromatographic method was developed for the simultaneous determination of hydroxyzine hydrochloride and benzyl alcohol in injection solutions. Separation was achieved using a mu Bondapak C18 column and the eluent [60% water, 25% acetonitrile, and 15% methanol containing 0.06% (v/v) sulfuric acid, 0.5% (w/v) sodium sulfate, and 0.02% (w/v) heptanesulfonic acid sodium salt] at a flow rate of 2 ml/min. Isobutyrophenone and p-nitroacetophenone were used as internal standards. The UV detector response at 257 nm was linear for hydroxyzine hydrochloride in the 3--10-mg/ml range and for benzyl alcohol in the 0.54--1.8 mg/ml range under analysis conditions. The method is accurate, simple, and precise.