Rapid determination of chloroprocaine and its major metabolite, 2-chloroaminobenzoic acid, in plasma by high-performance liquid chromatography.

A sensitive and specific high-performance liquid chromatographic method for determination of the 2-chloroprocaine, local anesthetic of ester type, and its major metabolite 2-chloroaminobenzoic acid, has been developed and validated. A single-step extraction procedure is employed followed by high-performance liquid chromatographic separation using reversed-phase column and analysis using variable length UV detection. Lidocaine was used as internal standard for 2-chloroprocaine measurement and p-aminobenzoic acid was used as internal standard for 2-chloroaminobenzoic acid analysis. The analysis of spiked plasma demonstrated good accuracy and precision of the method with limit of detection 0.1 microgram/ml for 2-chloroprocaine and 0.5 microgram/ml for 2-chloroaminobenzoic acid. The method has been used for pharmacokinetic studies in laboratory animals.