Compared to pelubiprofen, a cyclooxygenase-2-selective inhibitor, pelubiprofen tromethamine has been reported to exhibit improved solubility and absorption. Pelubiprofen tromethamine combines the anti-inflammatory effect of pelubiprofen with the gastric protective function of tromethamine salt, making it a relatively safe class of non-steroidal anti-inflammatory drugs with low levels of gastrointestinal side effects in addition to its original analgesic, anti-inflammatory, and antipyretic effects. This study assessed the pharmacokinetic and pharmacodynamic characteristics of pelubiprofen and pelubiprofen tromethamine in healthy subjects. Two independent clinical trials were performed in healthy subjects using a randomized, open-label, oral, single-dose, two-sequence, four-period, crossover design. In Study I and Study II, subjects received 25 mg of pelubiprofen tromethamine and 30 mg of pelubiprofen tromethamine, respectively, with 30 mg of pelubiprofen being the reference. Study I fell within the bioequivalence study criteria. A trend of increased absorption and exposure for 30 mg of pelubiprofen tromethamine vs. the reference in Study II was observed. The maximum cyclooxygenase-2 inhibitory effect of 25 mg of pelubiprofen tromethamine was approximately 98% compared to the reference, showing no significant pharmacodynamic variation. It is thus predicted that 25 mg of pelubiprofen tromethamine would show no clinically significant discrepancies in clinical analgesic and antipyretic effects from 30 mg of pelubiprofen.
Keywords: COX-2 inhibitory effect; comparative pharmacokinetics/pharmacodynamics; phase I; tromethamine salt.