High-performance liquid chromatographic assay for the determination of paracetamol, pseudoephedrine hydrochloride and triprolidine hydrochloride.

The different UV absorption characteristics of paracetamol, pseudoephedrine hydrochloride and triprolidine hydrochloride have been used to facilitate their determination in pharmaceutical preparations by HPLC. The method developed involves isocratic, reversed-phase chromatography. A 'wavelength switching' programme is preferred to the use of a compromise wavelength for all three compounds. This gives reasonable UV responses despite widely different UV characteristics and concentrations of drugs. The limits of quantitation are found to be within 200-700 micrograms ml-1 for paracetamol, 24-84 micrograms ml-1 for pseudoephedrine HCl and 1.0-4.0 micrograms ml-1 for triprolidine HCl. The method performs well in terms of precision and accuracy as indicated by linear regression analysis.