Pharmacokinetic Study of Aceclofenac and its Metabolites, and Application to Bioequivalence Study

아세클로페낙과 그 대사체의 약물동태 연구 및 생물학적 동등성

Aceclofenac, a nonsteroidal antiinflammatory agent of a phenylacetic acid type, has been used for rheumatoid arthritis and osteoarthrits. Although the metabolic pathway of aceclofenc is relatively well-known in vitro, pharmacokinetic profiles of its three major or metabolites are still unclear in human. The present study was designed to investigate pharmacokinetic profiles of the metabolites of aceclofenac, and to evaluate the bioequivalence of the generic preparation of aceclofenac 100 mg tablet. Blood samples were serially collected for a period of 12 hours following a single oral administration of 100 mg aceclofenac in 20 healthy human volunteers. A simple protein precipitation with acetonitrile was employed to purify those substances from plasma. Aceclofenac, diclofenac, 4'-hydroxyaceclofenac and 4'-hydroxy-diclofenac in heparinized plasma were simultaneously measured with flufenamic acid, an internal standard, using HPLC coupled to a tandem mass spectrometer. Time courses of 4'-hydroxydiclofenac, diclofenac and aceclofenac plasma concentrations were clearly revealed, and the pharmacokinetic properties were analyzed. The 90% confidence intervals for the ratios of test/reference for log-transformed AUC and $C_{max}$ lie within 0.80-1.25.