Simultaneous Determination of Valproate Sodium and Preservative in Sodium Valproate Oral Solution by HPLC

OBJECTIVE To establish an HPLC method for simultaneous determination of valproate sodium and antiseptic in sodium valproate oral solution. METHODS Thermo Hypersil BDS C₁₈ chromatographic column(250 mm×4.6 mm, 5 μm) was used. The isocratic elution was adopted, with the mobile phase composed of PBS (pH 2.3)-acetonitrile(63:37). The flow rate was 1.0 mL·min^-1 and the detective wavelength was 210 and 254 nm. RESULTS The linear range of valproate sodium was 0.99-2.92 mg·mL^-1 and the regression coefficient was 0.999 9. The recovery was 98.8%(RSD=0.5%). The linear range of sodium methylparaben was 14.74-58.96 μg·mL^-1 and the regression coefficient was 0.999 9. The recovery was 100.8% (RSD=0.4%). The linear range of sodium propylparaben was 10.21-20.41 μg·mL^-1 and the regression coefficient was 0.999 9. The recovery was 101.1%(RSD=0.8%). CONCLUSION The method is simple, quick and reliable. It can be used for actual test and quality control of sodium valproate oral solution.