title: High-performance liquid chromatographic determination of 1,2-diethyl-3-hydroxypyridin-4-one and its 2-(1-hydroxyethyl) metabolite in rat blood.
abstract: A sensitive and selective high-performance liquid chromatographic (HPLC) method for the analysis of 1,2-diethyl-3-hydroxypyridin-4-one (CP94, I) and its 2-(1-hydroxyethyl) metabolite (II) in rat blood is described. I, II and the internal standard, 1-propyl-2-ethyl-3-hydroxypyridin-4-one (CP95, III) were extracted into dichloromethane (3 x 5 ml, with the addition of 1 g of sodium chloride) from blood (0.25 ml plus 0.75 ml of pH 7.0 morpholinopropanesulphonic acid buffer). Extractability approached 100% for I and III, and approximately 65% for II under these conditions. Chromatographic analysis was carried out using a Hypercarb porous graphitised carbon HPLC column (10 cm x 0.46 cm). The mobile phase was 14:86 (v/v) acetonitrile-NaH2PO4 buffer (10 mM, containing 2 mM EDTA, pH adjusted to 3 with phosphoric acid) and detection was by ultraviolet at 280 nm. Calibration curves were linear (correlation coefficient greater than 0.99) and reproducible over the concentration range 0-80 micrograms/ml and the coefficient of variation was less than 16% even at low (1 microgram/ml) concentrations. The minimum quantifiable level was 0.5 microgram/ml for both I and II.
authors.affiliation: Chelsea Department of Pharmacy, King's College London, UK.
authors.forename: R O
authors.initials: RO
authors.lastname: Epemolu
authors.forename: S
authors.initials: S
authors.lastname: Singh
authors.forename: R C
authors.initials: RC
authors.lastname: Hider
authors.forename: L A
authors.initials: LA
authors.lastname: Damani
mesh_terms: D000818:Animals; D002851:Chromatography, High Pressure Liquid; D006900:Hydroxylation; D011728:Pyridones / Q000097:blood* / Q000493:pharmacokinetics; D051381:Rats; D012015:Reference Standards
chemical_list: D011728:Pyridones; C068543:1,2-diethyl-3-hydroxypyridin-4-one; C074118:1-ethyl-2-(1-hydroxyethyl)-3-hydroxypyridin-4-one