Problem statement: Lung-Ventilating-Regulating Oral Liquid is specified for cough, antipathy to cold by fever, nasal obstruction or discharge, headache, anhidrosis, and pain. It has effects of releasing exterior syndrome, dissolving cold, smoothing lung, and get rid of cough.
Objective: To develop a High Performance Liquid Chromatography (HPLC) method for ephedrine, hesperidin, and baicalin in Lung-Ventilating-Regulating Oral Liquid.
Methods: The three active constituents were identified in an Agilent TC-C18 (2) chromatographic column (250 mm × 4.6 mm, 5 μm), 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).
Results: 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 0.160-4.000 μg, respectively. And coefficients of recovery of these three kinds of samples showed 100.2%, 98.7%, and 97.8%, respectively.
Conclusion: The developed method is convenient, accurate, and well repeatable, and consequently can be applied for the quality control of Lung-Ventilating-Regulating Oral Liquid.