Pharmacokinetic evaluation of two ibuprofen-codeine combinations

The pharmacokinetics of ibuprofen and codeine were compared when given alone or in combination. Six treatments (ibuprofen 400 mg, codeine 60 mg, ibuprofen 400 mg and codeine 30 mg in two separate tablets, ibuprofen 400 mg and codeine 30 mg in one combination tablet, ibuprofen 400 mg and codeine 60 mg in two separate tablets, and ibuprofen 400 mg and codeine 60 mg in one combination tablet) were evaluated. Twenty-four healthy subjects were enrolled in the randomized block design study. Ibuprofen and codeine plasma concentrations were measured by reversed-phase liquid chromatography with UV and fluorescence detection. Pharmacokinetic parameters were estimated by non-compartmental data analysis techniques. Ibuprofen and codeine pharmacokinetic parameters obtained in this study were in agreement with previously published values. In addition, no pharmacokinetic interaction could be detected between codeine and ibuprofen when given alone or in combination. Furthermore, the similar half-life of both drugs (2-2.5 h) is advantageous for a fixed drug combination. The results suggest that ibuprofen and codeine can be given safely in a single oral dosage form.