High-performance liquid chromatographic (HPLC) determination of lobenzarit in plasma and its application to a bioavailability study in beagle dogs.
A method for the quantitative determination of lobenzarit (2-[(2-carboxyphenyl)amino]-4-chlorobenzoic acid) in dog plasma by high-performance liquid chromatography with UV detection (308 nm) is described. Plasma samples (200 microliters) were treated with acetonitrile and centrifuged, and the clear supernatant injected onto a reversed-phase phenyl column. The method achieved a limit of quantitation of 0.5 micrograms/ml in plasma, and the response was linear to 100 micrograms/ml. Comparing a solution and a tablet formulation given to beagle dogs, the assay demonstrated that the solution formulation was slightly more bioavailable and yielded a more variable absorption rate. The elimination of lobenzarit from plasma followed a biexponential time course, with an apparent terminal disposition half-life of between 5.8 and 10.7 hr.
Schwende
F J
FJ
Drug Metabolism Research, Upjohn Company, Kalamazoo, Michigan 49001.
Turner
S W
SW
D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000008:administration & dosage / Q000097:blood* / Q000493:pharmacokinetics; D001682:Biological Availability; D002851:Chromatography, High Pressure Liquid; D004285:Dogs; D008297:Male; D015203:Reproducibility of Results; D012996:Solutions; D013607:Tablets; D062367:ortho-Aminobenzoates / Q000008:administration & dosage / Q000097:blood* / Q000493:pharmacokinetics
D000894:Anti-Inflammatory Agents, Non-Steroidal; D012996:Solutions; D013607:Tablets; D062367:ortho-Aminobenzoates; C015735:lobenzarit