液相色谱-串联质谱法测定人血浆中阿扑吗啡

盐酸阿扑吗啡(apomorphinehydrochloride)为吗啡的衍生物,系中枢多巴胺D2受体激动剂,其舌下片制剂是目前用于治疗男性勃起机能障碍的新药。为了研究该制剂中阿扑吗啡的药代动力学特性,我们建立了阿扑吗啡血药浓度测定的液相色谱-串联质谱法。测定了28名健康志愿者口服阿扑吗啡舌下片后阿扑吗啡的血药浓度。已有文献报道采用HPIC-UV、HPLC-荧光、HPLC-电化学和GC等方法测定血浆中阿扑吗啡浓度,在灵敏度方面均低于我们所建立的方法。     

Determination of apomorphine in canine plasma by liquid chromatography-electrospray ionization mass spectrometry and its application to a pharmacokinetic study

An LC-ESI-MS method was developed and validated for the assay of apomorphine in canine plasma using one-step liquid-liquid extraction. The analytes were separated on a Phenomenex Gemini C18 (150 mm x 2.0 mm id 3 microm) column and determined by MS in the positive ion mode. The linear range was 0.4-40 ng/mL with an LOD of 0.2 ng/mL for apomorphine in plasma. The intraday and interday precision and accuracy of quality control samples were < 5.9% RSD and < 7.5% bias for apomorphine. Extraction recoveries were > 80%. The validated method was successfully applied to analyze canine plasma samples in a pharmacokinetic study of apomorphine in dogs and detailed pharmacokinetic parameters were calculated.     

Selective and quantitative isolation and determination of apomorphine in human plasma.

A simple extraction system for the selective and quantitative isolation of apomorphine from human plasma is described. Apomorphine and N-n-propylnorapomorphine were isolated by complex formation between a borate group and the diol group of the apomorphines in an alkaline medium, this in combination with ion-pair formation. The reproducibility and linearity of this extraction method combined with high-performance liquid chromatography with electrochemical detection is excellent. The absolute mean recovery of apomorphine was 100%, the recovery of N-n-propylnorapomorphine was 98%. The detection limit of apomorphine in human plasma in the described system is approximately 0.5 ng/ml.     

Development of a gas chromatographic/mass spectrometric method to quantify R(-)-apomorphine, R(-)-apocodeine and R(-)-norapomorphine in human plasma and urine

A method was developed and validated for the analysis of R(-)-apomorphine, (R-)-apocodeine and R(-)-norapomorphine in human plasma and urine with N-propylnorapomorphine as internal standard using gas chromatography/mass spectrometry (GC/MS) and single-ion monitoring after a single liquid-liquid extraction and silylation of compounds. The quantification limits were 1 ng/ml for apomorphine and apocodeine and 25 ng/ml for norapomorphine. Calibration curves were linear, within the range 1-100 ng/ml. Variation in intraday and interday precision was below 10%. This method was applied to study apomorphine bioavailability in nine patients with Parkinson's disease before and after coadministration of a catechol-O-methyl transferase inhibitor.     

Determination of Apomorphine in Tablets Using High Performance Liquid Chromatography with Electrochemical Detection

Abstract

A rapid and selective method using high performance liquid chromatography with electrochemical detection is described for the determination of apomorphine in tablets. Tablet mixes were dissolved in a standard volume of mobile phase containing the internal standard, N-n-propylnorapomorphine. Separation was achieved on a μ-phenyl column using methanol-acetonitrile-0.05M KH₂PO₄ (5:15:80) as mobile phase. The eluted compounds were detected with a sandwich-type electrochemical detector employing a glassy carbon working electrode and operated at 0.5V. Satisfactory accuracy and precision were obtained during analyses of tablets containing apomorphine.     

Development of a sensitive and rapid liquid chromatography/tandem mass spectrometry method for the determination of apomorphine in canine plasma

A sensitive, rapid and specific quantitative liquid chromatography/tandem mass spectrometry (LC/MS/MS) method was developed and validated for the determination of apomorphine (APO) in canine plasma. The analytes were prepared using one-step liquid-liquid extraction, and analyzed on a Waters Symmetry C(18) column interfaced with triple quadrupole tandem mass spectrometer. A mixture of methanol/0.1% formic acid in water (70: 30, v/v) was employed as the isocratic mobile phase. Positive electrospray ionization was utilized as the ionization source. The analyte and clenbuterol (internal standard) were both detected using multiple reaction monitoring (MRM) mode. The limit of detection (LOD) obtained was 0.03 ng/mL. The assay was linear over the concentration range of 0.1-100 ng/mL, and provided good precision (RSD) and good accuracy (RE). The analyte was stable by using antioxidants throughout the whole study. The experimental results show that LC/MS/MS is a rapid and sensitive method to analyze APO in plasma. Finally, the proposed method was successfully applied to a pharmacokinetic study of APO after intranasal administration of 0.5 mg apomorphine to 10 healthy beagle dogs.     

Chiral capillary electrophoretic method for quantification of apomorphine

A new method for chiral determination of apomorphine enantiomers was developed and validated. Seven different neutral and charged cyclodextrins were tested for enantioselectivity on R,S-apomorphine. Sulfobutylether-beta-cyclodextrin was found to offer the best resolution, but with this system, four peaks were detected from a solution of the two enantiomers, which was suggested to be the result of different forms of the complex between the selector and apomorphine. A complexation constant was estimated for a complex of 1:1 ratio for the second and the fourth peak, whereas the other two peaks were fitted to a model ratio of 1:2 (analyte-selector). To avoid this phenomenon, hydroxypropyl-beta-cyclodextrin was then chosen as the chiral selector. An optimisation study was performed on three factors: concentration of the chiral selector, pH of the buffer, and applied voltage. Optimum conditions were: 14 mM of hydroxypropyl-beta-cyclodextrin, pH 3.0, and 16 kV. UV detection was at 200 nm. The method was validated at the chosen conditions, offering a limit of detection of 0.2 microM and a limit of quantification of 0.5 microM. The validated method was applied for the determination of R,S-apomorphine in a transport study with an in vitro cell culture model of the intestinal mucosa (Caco-2).     

高效液相色谱-质谱法测定性保健品中脱水吗啡、西地那非、前列地尔

建立了高效液相色谱-电喷雾电离质谱法同时测定性保健品中违禁药物脱水吗啡、西地那非和前列地尔的分析方法。样品用甲醇超声提取,用Zorbax Eclipse XDB-C18柱分离,以乙腈-0.5%甲酸水溶液作为流动相,以保留时间和质荷比对分离出的组分予以定性确证,用峰面积进行定量。结果表明,脱水吗啡、西地那非和前列地尔的线性范围分别为50.0~5000.0 μg/L,10.0~1000.0 μg/L和40.0~4000.0 μg/L,检出限(以信噪比为3计)分别为20.0,4.0和10.0 μg/L。样品的加标平均回收率为89%~95%,相对标准偏差为9.5%~11%。该方法简便、快速、灵敏,适用于含中药成分的性保健品中这3种药物的同时分析。     

Neue spektrophotometrische Mikromethode zur Apomorphinbestimmung unter Verwendung der Oxydation mit Sauerstoff in alkalischer L?sung

Ohne Zusammenfassung

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New spectrophotometric micromethod for the determination of apomorphine using the oxidation with oxygen in alkaline solution

     

Chromatographic analysis of some drugs employed in erectile dysfunction therapy: Qualitative and quantitative studies using calixarene stationary phase

In this study, the effect of change in chromatographic process variables on the retention behavior of four drugs employed in erectile dysfunction therapy on a calixarene stationary phase is described. Three of these drugs are known to treat erectile dysfunction, namely, sildenafil citrate, tadalafil, and apomorphine hydrochloride, and one drug that is used as opioid analgesic, tramadol hydrochloride, which is quiet widely misused to treat premature ejaculation. The results indicate the importance of considering the structure and pK_a values of drugs to be separated along with mobile phase composition. A new optimized, rapid, and accurate liquid chromatography method is also established for simultaneous determination of sildenafil citrate, tadalafil, and apomorphine hydrochloride in pharmaceutical preparations and bulk powders. The chromatographic separation of the three pharmaceuticals was achieved on a calixarene column in less than 10 min using a binary mobile phase of 35% acetonitrile and 65% 50 mM sodium perchlorate pH2.5 at 1 mL/min flow rate. The method was validated for system efficiency, linearity, accuracy, precision, limits of detection and quantitation, specificity, stability, and robustness. Statistical analysis proved that the method enabled reproducible and selective quantification of all three analytes in bulk drugs and in pharmaceutical preparations.     

Synthesis of C-3 Halogene-Substituted Apocodeines and Apomorphines

A new effective method has been elaborated for the preparation of the hitherto unknown C-3 halogene derivatives (Cl, Br) of apocodeine and apomorphine, as well as of their N-demethyl-N-substituted (N-propyl, N-alkyl) analogues. These compounds are expected to possess an effect on the dopamine receptor system.     

Structural Analogues Of Aporphines Part 1: Synthesis of Apomorphines with the Catechol Moiety Replaced by 5-membered Heterocycles

Analogues of apomorphine (1) having the catechol moiety replaced by pyrrole (→ 10 , 18 ), pyrazole (→ 12 ), isoxazole (→ 13 , 14 ), thiazole (→ 16 ) and thiadiazole (→ 20 ) ring systems have been synthesized from the key intermediate ketone 6 .     

Rapid Determination of Apomorphine in Brain and Plasma Using High-Performance Liquid Chromatography

Abstract

A new method for quantitative determination of apomorphine in mouse brain and rat plasma is described. The drug was extracted utilizing SEP-PAK C₁₈ cartridge, and quantified by high performance liquid chromatography with electrochemical detector. The average recovery was 92 ± 2.8% with a day-to-day coefficient of variation of 10.2%. Apomorphine concentration in mouse brain and in rat plasma, as a function of dose and time, after injection with apomorphine-HCl were determined. The results indicate that the method is adequate for pharmacokinetic studies.     

Structure-activity relationships for apomorphine congeners. Conformational energies vs. biological activities

Summary A series of apomorphine congeners has been studied with respect to their ability to mimic the structural requirements of the dopamine pharmacophore in the potent and stereoselective dopamine receptor agonist (R)-apomorphine. Conformational energies of the mimicking structures calculated by molecular mechanics (MMP2) correlate well with the observed biological activities.     

Fluorescence Behavior of Phenolic Compounds in Solutions Containing Micelles

Abstract

The effects of micelles on the fluorescence detection of phenolic compounds are described. Micelles were found to enhance the fluorescence of the drugs apomorphine (APO), and N-n-propylnorapomorphine (NPA), and a series of model hydroxybiphenyls. The fluorescence enhancements were pH dependent and biphasic behavior in hexadecyltrimethylamnonium chloride was observed for APO and NPA. Multiple equilibria and formation of zwitterions of the phenolic aporphines in the micellar environment is proposed to explain this behavior. Micellar fluorescent enhancements should be useful in improving the sensitivity of fluorometric determinations of polar compounds.     

Synthesis of supposed enone prodrugs of apomorphine and N-propyl-norapomorphine

We have previously demonstrated that the enone prodrug GMC-6650 acts as a highly efficient dopaminergic agonist. In vivo, this compound is bioactivated to its corresponding catecholamine, TL-334. The goal here was to investigate if this bioactivation also occurs for the supposed enone prodrug of apomorphine. We describe the 12-step synthesis of this supposed prodrug, 6-alkyl-5,6,6a,8,9,10-hexahydro-4H-dibenzo[de,g]quinolin-11(7H)-one (R=Me, n-Pr).     

Immobilised gold nanostars in a paper-based test system for surface-enhanced Raman spectroscopy

Paper-based SERS active substrates were prepared adsorbing spherical and star-shaped gold nanoparticles on a standard filter paper support. Besides the deposition conditions, morphological parameters of the particles were found to strongly affect the enhancer properties of the substrates. The developed substrate was tested regarding surface homogeneity as well as in the quantitative analysis of malachite green, – a well documented Raman reporter dye – and proved to be capable also to detect the oxidation products of apomorphine, a well-known drug molecule used in Parkinson's disease. This material is simple to prepare, easy to handle and dispose and as such it could be a perfect target for further development of a new family of mass-produced, cheap solid SERS substrates.     

A New and Efficient One-Pot Synthesis of Apomorphine and Its Ring-A Halogenated Derivatives1

Rearrangement and O-demethylation of codeine (2) and various 6-demethoxythebaine derivatives 6–11 with morphinane skeletone into apomorphine (3) and its halogenated derivatives 20–24 could be efficiently executed in a one-pot operation, by treatment with methanesulfonic acid/methionine.     

Comparison of two spectrophotometric assays for blood urea nitrogen: Influence of apomorphine

An animal model for apomorphine-induced azotemia is being sought. This investigation requires numerous blood urea nitrogen (BUN) determinations in the presence of apomorphine (APO). Aqueous solutions of APO undergo spontaneous oxidation in air producing a blue-green chromagen. The urease-Berthelot and Fearon spectrophotometric assays for the determination of BUN rely on the production of colored chromagens. The purpose of this investigation, therefore, was to determine (1) if the presence of APO in plasma samples interferes with the measurement of BUN and (2) what is the method of choice for measuring BUN. The results indicate that (1) APO does not interfere with BUN determinations by either method and (2) the urease-Berthelot procedure has the greater accuracy and is the method of choice for routine determinations of BUN.     

Comparison of high-performance liquid chromatography electrochemical detectors for the determination of aporphines,catecholamines and melatonin

A Bioanalytical Systems detector showed a greater sensitivity for low-level determinations of apomorphine, norepinephrine, epinephrine, dopamine, and melatonin compared to a Brinkmann Instruments system. Modifications of the Bioanalytical Systems flow cell, which have been developed in our laboratories, increase the sensitivity toward certain catecholic compounds, generally decrease baseline noise, and allow for serial coupling of detectors.²