Determination of Thioctic Acid Content and Relative Substances in Thioctic Acid Injection by RP-HPLC

OBJECTIVE To establish a HPLC method for the determination of thioctic acid content and relative substances in thioctic acid injection. METHODS The HPLC was carried out on an Intersil C18 column at room temperature. The mobile phase was 0.005 mol·L-1 KH2PO4 (adjust pH to 3.5 by phosporic acid) -MeOH-acetonitrile (41∶51∶8), and the flow rate was 1.0 mL·min-1. The detection wavelength was set at 215 nm. RESULTS The linear range of calibration curve was 0.06~1.99 g·L-1. The average recovery and RSD were 100.5% and 0.35% (n=9), respectively. CONCLUSION The method is accurate, simple and rapid. The degradation products can be well separated. Therefore, the quality of thioctic acid injection can be effectively controlled.