Multiple-dose pharmacokinetics of naproxen from a controlled-release tablet in healthy volunteers

The pharmacokinetics of a new controlled-release tablet of naproxen (750 mg) given once daily has been studied in healthy volunteers, in comparison with two doses of the conventional naproxen tablets (375 and 500 mg) administered twice daily. Steady-state plasma concentrations of naproxen were achieved after two days of repeated administration of both the controlled-release and the conventional tablets. On day seven, peak concentration, cowest concentration and the steady-state average plasma concentration values of the controlled-release tablet were significantly higher than those of 375 mg conventional tablet and comparable to those of 500 mg conventional tablet. Areas under the plasma concentration-time curve indicated an equal extent of absorption between the new and the conventional formulation. Overall the controlled-release tablet administered once daily mimicked a twice daily regimen so suggesting that the new formulation could be suitable for once daily dosing.