An accurate. simple, reproducible and sensitive method for the determination of paracetamol, caffeine and codeine phosphate has been developed and validated. Paracetamol, caffeine and codeine phosphate were separated using a mu Bondapack C-8 column by isocratic elution with flow rate 1.0 ml/min. The mobile phase composition was 420/20/30/30 (v/v/v/v) 0.01 M KH2PO4, methanol, acetonitrile, isopropyl alcohol and spectrophotometric detection was carried out at 215 nm. The linear range of detection for paracetamol, caffeine and codeine phosphate were between 0.400 and 1500 mug/ml: 0.075 and 90 mug/ml: 0.300 and 30 mug/ml, respectively. The method has been shown to be linear, reproducible, specific, sensitive and rugged. (C) 2001 Elsevier Science B.V. All rights reserved.