A simple, rapid and reliable high performance liquid chromatographic method for simultaneous determination of compounds typically found in complex cold medicines (i.e. acetaminophen, bromvalerylurea, bucetin, caffeine, chlorpheniramine maleate, dextromethorphan HBr, ethoxybenzamide, guaifenesin, methylephedrine HCl, noscapine HCl) has been developed. Isocratic separation was performed using an Inertsil ODS-3V column (5 μm, 25 cm x 4.6 mm i.d.) with a mobile phase: 0.2% triethylamine, 2% tetrahydrofuran in 0.1% H3PO4: CH3CN (85: 15; pH=2.70), flow rate 1.0 ml/min. An ultraviolet spectrophotometer was used as the detector at the wavelength of 205 nm. The precision and accuracy were satisfactory. The system can be used to assay the above compounds at typical cold medicine dosage forms.

Key words: complex cold medicine formulations, HPLC