Comparative pharmacokinetics of ketoprofen derived from single oral doses of ketoprofen capsules or a novel sustained-release pellet formulation

Abstract

Nine healthy male volunteers took part in a crossover study to compare the pharmacokinetics of ketoprofen after administration of a single oral dose (200 mg) of ketoprofen as ‘Orudis’ capsules of encapsulated stustatained-release pellets, ‘Oruvail’ . The mean ± standard deviation values for highest observed plasma ketoprofen concentrations were determined by high performance liquid chromatography to be 23 ± 11 μg ml−1 at 0±82 ± 0±18 h after dosing with ketoprofen capsules and 3·5 ± 1·0 μg ml−1 at 4·9 ± 1·0 h after dosing with sustained-release pellets. The apparent ketoprofen elimination half-lives after these treatments were 3·3 ± 1·2 h and 8·4 ± 3·4 h, respectively. The systemic availability of ketoprofen was essentially the same after each treatment. Administration of sustained-release pellets (containing 200 mg ketoprofen) once every 24 h is predicated to produce similar average and markedly higher minimum plasma ketoprofen concentrations than are produced by ketoprofen capsules (100 mg) every 12h, and similar minimum plasma ketoprofen concentrations to those achieved by dosing ketoprofen capsules (50 mg) every 6 h. Once-daily administration of a non-steroidal anti-inflammatory agent has an obvious therapeutic advantage over more frequent dosing. This study suggests that the sustained-release pellet formulation described herein is a suitable formulation for once-daily administration of ketoprofen.