Simultaneous identification of the three active constituents in Lung-Ventilating-Regulating Oral Liquid by RP-HPLC.

The study aimed to develop a HPLC method for ephedrine, hesperidin, and baicalin in Lung-Ventilating-Regulating Oral Liquid. The three active constituents were identified in an Agilent TC-C18 (2) chromatographic column (250mm × 4.6mm, 5µm), with 0.2% phosphoric acid solution - methyl cyanides as mobile phase, which was performed at a gradient elution column temperature of 25oC and a flow rate of 0.8 mL•min-1. Then the eluate was detected at detection wavelengths of 207 nm (for ephedrine) and 278 nm (for hesperidin and baicalin). Under the chromatographic conditions, ephedrine, hesperidin, and baicalin were well separated, which showed good linear relationships at 0.158-2.370, 0.164-4.100 and 0.160-4.000µg, respectively. The coefficients of recovery of these three kinds of samples showed 100.2%, 98.7% and 97.8%, respectively. The developed method is convenient, accurate and well repeatable, and consequently can be applied for the quality control of Lung-Ventilating-Regulating Oral Liquid.