Determination of Temazepam and Its Active Metabolite, Oxazepam in Plasma, Urine and Dialysate Using Solid-Phase Extraction Followed by High Performance Liquid Chromatography

Abstract A sensitive and rapid assay of temazepam and its active metabolite, oxazepam in plasma, urine and dialysate was developed. This assay involves solid phase extraction followed by HPLC analysis. Mean recoveries were 97 % for temazepam and 70 % for oxazepam. The limit of detection was 5 ng/ml of biological fluids for each compound. One advantage of this method lies in the solid phase extraction which is more rapid and convenient than liquid liquid extraction. This assay maybe useful for monitoring concentrations of temazepam and oxazepam in plasma, urine and dialysate of patients under continuous ambulatory peritoneal dialysis (CAPD).