Ritanserin assessments in plasma and CSF by means of HPLC technique with fluorescence detection

A specific HPLC-technique based on fluorescence detection was developed for assay of ritanserin, a serotonin receptor-blocking agent, in plasma and CSF. In 5 ml sample volumes, the limit of detection was 0.5 ng/ml, the recovery of ritanserin was 83 +/- 5%, and the inter-assay variability, expressed as the coefficient of variation, was 9.5% in the 2-788 ng/ml concentration range. When the values determined by this technique were compared with the results obtained by means of an independent HPLC-method with UV-detection, the coefficient of correlation was 0.995 (p less than 0.001). However, our technique proved to be more specific and less complicated.