Gas chromatographic methods for the determination of antiepileptic drugs: a systematic review

Despite the availability of a variety of methods for determining the concentrations of antiepileptic drugs in body fluids--including thin-layer chromatography, high pressure liquid chromatography, radioimmunoassay, etc.--gas chromatography remains perhaps the routinely used tool for therapeutic drug monitoring in this area. As a result of the need to improve precision and reproducibility, as well as to reduce costs, among other factors, there has been a continuous technical improvement in the technique. And in the last 10 years, more than 100 papers have described gas chromatography for the determination of antiepileptic drugs. Needless to say, only a small percentage of these publications described methods of a significantly new character. In order to facilitate the task, of comparing methods for the purpose of choosing a technique suitable to a specific need, we have reviewed the analytic parameters described in the 114 publications of the last decade. These parameters include the following: (1) drugs determined, (2) internal standard, (3) amount of sample, (4) extraction procedure, (5) preparation of derivatives, (6) sample injection, (7) detection, (8) column support and temperature, and (9) stationary phase. We present these data in a comprehensive tabular form together with a number of comments concerning specific techniques.