Abstract
Ethyl 8-oxo-5,6,7,8-tetrahydrothiazolo[3,2-a][1,3]diazepin-3-carboxylate (HIE-124) is one of a new generation of ultra-short-acting hypnotics. A high-performance thin-layer chromatographic (HPTLC) method has been established as the first reported method for quantitative analysis of HIE-124 in plasma. Baseline resolution between HIE-124 and diazepam (internal standard) was achieved on HPTLC plates with chloroform-ethyl acetate 80:20 (v/v) as mobile phase. Densitometric detection was performed at 265 nm. The method was linear in the range 40-400 mu g mL(-1) (R = 0.997) and recoveries of the drug were in the range 93-102% at 80-350 mu g mL(-1). Within-run and between-run precision calculated as RSD [%], and accuracy calculated as percentage error were in the ranges 2.1-4.6% and 0.8-6.9%, respectively. The limits of detection (LOD) and quantification (LOQ) in spiked human plasma were 20 and 40 mu g mL(-1) (40 and 80 ng per band), respectively.