Determination of selected antiepileptic drugs in mouse brain homogenates by HPLC—DAD

Abstract

Summary. Three independent reversed phase high-performance liquid chromatography (HPLC) procedures with diode array detection (DAD) for the analysis of carbamazepine (CBZ), topiramate (TPM), and valproic acid (VPA) have been developed in order to determine drug penetration of the blood-brain barrier. Determination of CBZ was performed on C18 column with mobile phases containing methanol (55%, v/v), acetate buffer at pH 3.5 (20%, v/v), double distilled water (25%, v/v), and 0.025 M L −1 diethylamine (DEA). The mobile phase containing acetonitrile and water (8:2, v/v) or acetonitrile and phosphate-citrate buffer at pH 2.6 (1:1), respectively, for analysis of VPA and TPM was applied. Quantification of carbamazepine was performed at 285 nm without extraction procedure before the analysis. Determination of topiramate and valproic acid was performed using precolumn derivatization with 9-fluorenylmethyl chloroformate (FMOC-Cl). FMOC-Cl is a suitable agent, which reacts with both primary and secondary amines and also with acidic groups. Topiramate was determined at 263 nm and valproic acid at 300 nm. The proposed procedures are simple, not time-consuming, and suitable for the determination of investigated compounds in mouse brain homogenates.

Use of TLC-Densitometric Method for Determination of Valproic Acid in Capsules

“…They are useful in monitoring the therapeutic concentration of a substance, treatment progress, and side effects. Several methods for determination of valproic acid are known, namely: thin layer chromatography [5], liquid chromatography [6][7][8][9], high performance liquid chromatography [10][11][12][13][14][15][16][17][18][19][20][21][22][23][24], ultra high performance liquid chromatography [4,25,26], ultra performance liquid chromatography [27][28][29][30][31], gas chromatography [4,18,[32][33][34][35][36][37][38], capillary electrophoresis [39,40], voltamperometry [41], valproateselective electrode [42], and colorimetry [43].…”

“…The vast majority of valproic acid was determined in biological samples [4][5][6][7][8][9][10][11][12][13]16,[19][20][21][22][24][25][26][27][28][29][30][31][32][33][34][35][36][38][39][40]. Only a few studies report the determination of valproic acid in pharmaceutical preparations [14,17,20,23,35,37,41,42].…”

Spectrophotometric determination of ranitidine hydrochloride (RNH) in pharmaceutical formulation using 9-fluorenylmethyl chloroformate (FMOC-Cl)

“…Derivatization reactions, often selective for amine type (primary, secondary, tertiary) have also been used to improve the detection and separation of these amines 18 . 9-Fluorenylmethyl chloroformate (FMOC-Cl) is a useful derivatizing agent used for the determination of amino acids, primary and secondary amines in alkaline conditions and the resulting derivatives are stable [19][20][21] . However, application of FMOC-Cl for derivatization of carboxylic acid has also been reported 22 .…”