A sensitive high-performance thin-layer chromatographic method has been developed for analysis of oxcarbazepine (OXC) in human plasma. This paper describes extraction of OXC from spiked human plasma by protein precipitation with acetonitrile and quantification using normal-phase HPTLC. The optimized mobile phase was ethyl acetate-toluene-methanol 7.0:2.0:1.0 (
). The detection was performed densitometrically at 254 nm by UV absorption. The detection limit of OXP is 2 ng and the limit of quantification is 10 ng (
= 6). A good correlation coefficient (
= 0.99) was obtained for amounts of OXC in the range 10 to 3000 ng. Recovery was 75 to 80%. The internal standard used was chlorzoxazone, which was well resolved from OXC under the conditions specified. Analysis of OXP in human plasma was successfully performed without interference from endogenous materials.
, The Merck Index,13
edn, Merck & Co., White House Station, NJ, 2001, 6998.