title: Liquid chromatographic determination of manidipine in serum with electrochemical detection.
abstract: A highly sensitive and selective method for determining a dihydropyridine calcium antagonist, manidipine, by liquid chromatography using column switching with electrochemical detection was developed. Manidipine in serum was extracted by a rapid and simple procedure based on C8 bonded-phase extraction and then silica extraction. Manidipine and nilvadipine as an internal standard were separated on a C8 bonded-phase HPLC column and detected by high conversion efficiency amperometric detection at +0.7 V. Manidipine and nilvadipine (I.S.) were separated from an endogenous interference peak in serum and concentrated on a pre-column (C18) by column switching using an isocratic mobile phase, and then the corresponding fractions were introduced to an analytical column with a C8 stationary phase. Determination of manidipine was possible over the concentration range 0.5-10 ng/ml: the limit of detection was 0.3 ng/ml. The recovery of manidipine added to serum was 93.1-98.4% with coefficients of variation of less than 7.1%. The method is applicable to drug level monitoring in the serum of healthy volunteers treated with manidipine and to the analysis of pharmacokinetics.
authors.affiliation: Department of Pharmacy, Hirosaka University Hospital, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Ohkubo
authors.forename: T
authors.initials: T
authors.lastname: Uno
authors.forename: K
authors.initials: K
authors.lastname: Sugawara
mesh_terms: D002121:Calcium Channel Blockers / Q000097:blood*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004095:Dihydropyridines / Q000097:blood*; D004563:Electrochemistry; D006801:Humans; D009578:Nitrobenzenes; D010879:Piperazines; D012680:Sensitivity and Specificity
chemical_list: D002121:Calcium Channel Blockers; D004095:Dihydropyridines; D009578:Nitrobenzenes; D010879:Piperazines; C054218:manidipine