Simultaneous measurement of phenobarbital, carbamazepine, phenytoin and 5-(4-hydroxyphenyl)-5-phenylhydantoin in serum by high-performance liquid chromatography

Abstract

A rapid, highly sensitive high-performance liquid chromatographic method has been developed for the determination of phenobarbital, carbamazepine, phenytoin and its main metabolite, 544-hydroxyphenyl)-5-phenyl hydantoin, in 50 pl of serum. Serum protein was precipitated with an acetonitrile solution containing 5-(4-methylphenyl)-5-phenylhydantoin as the internal standard. The drugs were eluted from a 5 pm, C-18 reversed-phase column at 40 "C with a mobile phase consisting of an acetonitrilemethanolphosphate buffer of pH 4.8 (22 + 28 + 50% VIV), at a flow-rate of 1 ml min-1 with UV detection at 214 nm. Each analysis required no longer than 12 min. Quantitation was achieved by the measurement of the peak-height ratio and the relative and absolute recoveries varied from 94 to 109%. Within-day coefficients of variation ranged from 1.2 to 3.22% and between-day coefficients of variation from 2.0 to 3.4% in subtherapeutic, therapeutic and toxic concentrations. Keywords : High -perf0 rma nce liquid ch rom a tog rap h y; p h en o ba rbita I; ca rbam azep in e; p h en ytoin; 5-(4h ydroxyphen yl)-5-phen ylh ydantoinPaper A51299

Detection of anticonvulsants and their metabolites in urine within a “general unknown” analysis procedure using computerized gas chromatography-mass spectrometry

“…The identified drugs can then be quantified in plasma using methods described by Juergens (1986), Pang et al (1986), Mira et al (1987), Matsumoto et al (1988), Richard et al (1989) and Svinarov and Dotchev (1989) or reviewed by Burke and Thrnot (1985). Finally, several immunoassay techniques are commercially available for therapeutic drug monitoring of anticonvulsants.…”

High resolution micro‐SPECT scanning in rats using 125I β‐CIT: Effects of chronic treatment with carbamazepine

“…At 1 h prior to initiation of scanning, minipumps were surgically explanted and a blood sample withdrawn from the tail vein. Blood serum was isolated by centrifugation and stored at −20°C prior to determination of CBZ and carbamazepine‐10,11‐epoxide (CBZ‐E) concentrations by high performance liquid chromatography (HPLC) (Mira et al., 1987). At 45 min prior to initiation of scanning, animals were secured in a custom‐designed holder with an incisor bar attached to the anesthetic delivery system and injected with 18–20MBq of 125 I β‐CIT via the tail vein.…”

Determination of free and total levels of phenytoin in human plasma from patients with epilepsy by MEKC: An adequate alternative to HPLC

“…Several studies have been reported in the literature including using immunological techniques based upon fluorescence polarization immunoassay 4–6 and enzyme multiplied immunoassay (EMIT) 7, 8, gas chromatography 9–11, HPLC with UV detection 12–35, mass spectrometry 36, and techniques based upon CE on the study of phenytoin concentration of free level and/or total level in human biological samples. EMIT is a simple and rapid method for screening urine and blood for legal or illicit drugs.…”