ABSTRACT
The study describes a specific, precise, sensitive and accurate method for determination of unchanged captopril, an angiotensin-converting enzyme inhibitor, in human plasma. Captopril was stabilized by forming an adduct with p-bromophenacyl bromide and this adduct was measured by high-performance liquid chromatography with UV detection. The standard curve was linear over a range of 30-800 ng ml-1. The average yield of derivatization of the unchanged captopril was 73.6% and the recovery of captopril-adduct reached 93.1%. The limit of detection was 15 ng ml-1, while the quantitative limit was 30 ng ml-1. Inter- and intra-assay RSD was below 9%, but inter- and intra-assay accuracy was below 8%. On the basis of elaborated method, a single-dose pharmacokinetics in 12 men, in two doses (25 and 50 mg of captopril) has been investigated. The comparison of the pharmacokinetic parameters obtained from both doses of the drug have been made.
Subject(s)
Captopril/blood , Adult , Biological Availability , Captopril/administration & dosage , Captopril/pharmacokinetics , Chromatography, High Pressure Liquid , Humans , Indicators and Reagents , Male , Spectrophotometry, UltravioletABSTRACT
A gas-liquid chromatographic system with alpha-cyclodextrin in formamide medium (coated on Chromosorb) was used for the separation of enantiomers of alpha-pinene, beta-pinene, limonene and camphene in medicines applied in the therapy of liver and kidney diseases. The drugs under investigation were produced in Poland (Terpichol and Terpinex), in Germany (Rowachol and Rowatinex) and in Slovenia (Uroterp). It was found that, depending on the manufacturer, medicines possessing similar chemical compositions differ considerably from one another regarding the content of enantiomers, mainly those of alpha-pinene.
Subject(s)
Bridged Bicyclo Compounds/chemistry , Kidney Diseases/drug therapy , Liver Diseases/drug therapy , Monoterpenes , Terpenes/chemistry , Bicyclic Monoterpenes , Bridged Bicyclo Compounds/isolation & purification , Bridged Bicyclo Compounds/therapeutic use , Chromatography, Gas , Cyclohexenes , Drug Combinations , Flame Ionization , Humans , Limonene , Stereoisomerism , Terpenes/isolation & purification , Terpenes/therapeutic useABSTRACT
The fluorescence spectra of anethole and eugenol dissolved in methanol-aqueous binary systems with the addition of alpha- and beta-cyclodextrin were studied. Observed enhancement of the fluorescence intensity is possibly due to the higher quantum yield of the cyclodextrin-hydrocarbon inclusion complexes. The measured fluorescence intensities for eugenol and anethole in the presence of alpha- and beta-cyclodextrin were processed using principal component analysis. The results obtained suggest 1:1 and 2:1 complexation, as confirmed by a double reciprocal plot for terpenes complexed to cyclodextrins. In both cases (anethole and eugenol) detection limits were improved after addition of cyclodextrins. This phenomenon can be applied for improvement of direct fluorescence and HPLC-fluorescence assays.
