[Determination of sulpiride and sultopride by high-performance liquid chromatography for pharmacokinetic studies].

A high-performance liquid chromatographic method with UV detection (226 nm) for the analysis of sulpiride and sultopride in body fluids has been developed. Plasma, red blood cell (RBC) and urine samples were extracted by chloroform at pH 10. Internal standards were a new substituted benzamide (N-[(ethyl-1-pyrrolidinyl-2)methyl] methoxy-2-ethylsulphonyl-5-benzamide, DAN) for the sulpiride assay and sulpiride for the sultopride assay. The detection limit in plasma and RBC was 10 ng/ml for sulpiride and 15 ng/ml for sultopride. The proposed techniques were selective, reliable and sensitive enough to be used for pharmacokinetic studies and drug monitoring. Some plasma and RBC data from pharmacokinetic studies in healthy volunteers (sulpiride) or patients (sultopride) are presented. Half-lives determined from either plasma or RBC concentrations were similar (7 h for sulpiride and 5 h for sultopride).