[Plasma and tissue concentrations of biphenylacetic acid following 1 week oral fenbufen medication and topical administration of Felbinac gel on the knee joint].
In an randomised study 30 patients were treated during one week before undergoing an elective surgery of the knee joint with 1 or 2 g respectively of 3% Felbinac gel (biphenylacetic acid gel) or oral 300 mg Fenbufen thrice daily. Biphenylacetic acid (BPAA) is the therapeutically active metabolite of the non-steroid anti-inflammatory drug Fenbufen. Plasma concentrations were measured before, during therapy and at the time of the operation. During the surgery of the knee joint specimens of synovial fluid and -membrane, of cartilage, muscle and tendons as well as of the skin and the subcutaneous fatty tissue were obtained and the BPAA concentrations measured. There was a large variance of the obtained values in all groups. It seems that mainly methodical problems are responsible for this. At the time of surgery, the plasma concentrations following oral administration were with 10,080 ng/ml 20 to 50 times higher than those after topical administration. The tissue concentrations reached 1/8 to 1/2 of the plasma concentrations. The relation of tissue concentrations to plasma concentrations of BPAA was smaller in patients treated with oral administration than in patients treated with topical administration. Therefore a partial direct penetration of Felbinac into the deeper tissue compartments can be assumed. There was no significant difference in plasma-, synovial- or tissue concentrations between the two groups treated with the topical administration. The tissue concentrations were 1 to 2 orders of magnitude lower than those after oral administration. Only in the skin the concentrations were with 9160 respectively 3830 ng/g higher than those obtained after oral application (2110 ng/g).
Bolten
W
W
Rheumaklinik II Wiesbaden, Wiesbaden.
Salzmann
G
G
Goldmann
R
R
Miehlke
K
K
D000284:Administration, Oral; D000287:Administration, Topical; D000328:Adult; D000368:Aged; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000008:administration & dosage* / Q000493:pharmacokinetics; D001172:Arthritis, Rheumatoid / Q000188:drug therapy*; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D010003:Osteoarthritis / Q000188:drug therapy*; D010648:Phenylacetates / Q000008:administration & dosage* / Q000493:pharmacokinetics; D010654:Phenylbutyrates / Q000008:administration & dosage* / Q000493:pharmacokinetics; D016032:Randomized Controlled Trials as Topic
D000894:Anti-Inflammatory Agents, Non-Steroidal; D010648:Phenylacetates; D010654:Phenylbutyrates; C012776:biphenylylacetic acid; C010725:fenbufen
Plasma- und Gewebekonzentrationen von Biphenylessigsäure nach einwöchiger oraler Fenbufenmedikation bzw. topischer Anwendung von Felbinac-Gel am Kniegelenk.