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1.
Article in English | MEDLINE | ID: mdl-26940167

ABSTRACT

Bupropion hydrochloride is a norepinephrine-dopamine disinhibitor (NDDI) approved for the treatment of depression and smoking cessation. Bupropion is a trimethylated monocyclic phenylaminoketone second-generation antidepressant, which differs structurally from most antidepressants, and resides in a novel mechanistic class that has no direct action on the serotonin system. Comprehensive chemical, physical, and spectroscopic profiles are presented. This analytical profile provides an extensive spectroscopic investigation utilizing mass spectrometry, one- and two-dimensional NMR, solid-state NMR, IR, NIR, Raman, UV, and X-ray diffraction. The profile also includes significant wet chemistry studies for pH, solubility, solution, and plasma stability. Both HPLC and UPLC methodology are presented for bupropion and its related impurities or major metabolites. The profile concludes with an overview of biological properties that includes toxicity, drug metabolism, and pharmacokinetics.


Subject(s)
Antidepressive Agents, Second-Generation/administration & dosage , Bupropion/administration & dosage , Animals , Antidepressive Agents, Second-Generation/chemistry , Antidepressive Agents, Second-Generation/pharmacokinetics , Antidepressive Agents, Second-Generation/therapeutic use , Bupropion/chemistry , Bupropion/pharmacokinetics , Bupropion/therapeutic use , Chemistry, Pharmaceutical , Humans
2.
Anal Chem ; 71(8): 1579-84, 1999 Apr 15.
Article in English | MEDLINE | ID: mdl-10221076

ABSTRACT

An HPLC/MS/MS method has been developed for the characterization and quantification of ginsenosides contained in extracts of the root of Panax ginseng (Korean ginsengs) and Panax quinquefolius L. (American ginsengs). The [M + H]+ and [M + Na]+ ions were observed for ginsenoside standards (Rb1, Rb2, Rc, Rd, Re, Rf, Rg1) and four different ginseng extracts. The glycosidic linkages, the core, and the attached sugar(s) of the ginsenosides can be determined from the collision-induced dissociation spectra from the protonated molecules. The relative distribution of these ginsenosides in each extract of American or Korean ginseng was established.


Subject(s)
Central Nervous System Agents/analysis , Panax/chemistry , Plants, Medicinal , Saponins/analysis , Chromatography, Liquid , Ginsenosides , Mass Spectrometry
3.
J Chromatogr B Biomed Sci Appl ; 707(1-2): 161-7, 1998 Apr 10.
Article in English | MEDLINE | ID: mdl-9613945

ABSTRACT

A simple, rapid, sensitive and selective method has been developed for the stereospecific determination of verapamil and its metabolite, norverapamil in urine. For sample preparation we utilized a membrane-based solid-phase extraction (SPE) disk consisting of a thin, particle-loaded membrane inserted in a plastic syringe-like barrel. The particles, which may be C8 or C18 bonded phase (C8 in this work), are embedded within a matrix of PTFE (Teflon) fibrils. Overall analyte recoveries were above 85%, even at low concentration of 3.0 ng/ml with reproducibilities (C.V. values) below 13.1%. This method of extraction has the advantage of speed and considerable reduction in solvent volumes compared to conventional SPE and solvent extraction. The separation of all the enantiomers was achieved using a single chiral stationary phase column, the cellulose-based reversed-phase, Chiralcel OD-R. Analyte concentrations of less than 3.0 ng/ml could be quantitated with C.V. values below 14%. Calibration curves were linear in the range 2.5-300 ng/ml. Intra-day and inter-day reproducibilities were 10.5-14.2% at 3 ng/ml, 4.8-9.3% at 138.5 ng/ml and 7.8-10.1% at 280 ng/ml level, respectively, for all the enantiomers.


Subject(s)
Calcium Channel Blockers/urine , Verapamil/analogs & derivatives , Adult , Calibration , Chromatography, High Pressure Liquid , Humans , Indicators and Reagents , Polytetrafluoroethylene , Reproducibility of Results , Solvents , Specimen Handling , Stereoisomerism , Verapamil/urine
4.
J Chromatogr ; 652(1): 35-42, 1994 Jan 14.
Article in English | MEDLINE | ID: mdl-8014225

ABSTRACT

An automated technique involving switching valves and a filter assembly has been developed and evaluated for the on-line precipitation of proteins and peptides from plasma samples. In the set-up, the proteins were precipitated on-line by injecting the plasma sample into a stream of organic precipitating agent. The precipitates so formed are filtered on-line by a set of filter assemblies consisting of ordinary in-line HPLC solvent filters. Evaluation of the technique was performed using ibuprofen and a mixture of three estrogens, estradiol, equilin and estrone, spiked in dog plasma. The coefficients of variation (C.V.) for system suitability parameters were below 10%. Absolute recovery of ibuprofen in plasma ranged from 80% for 100 micrograms/ml to 114% for 5 micrograms/ml spiked concentrations, respectively. Resolution for equilin and estrone, two closely eluting peaks, was 1.79 (C.V. = 5.8%, n = 7). The switching-valve--filter assembly had no significant effect on the efficiency of the HPLC system.


Subject(s)
Pharmaceutical Preparations/analysis , Plasma/chemistry , Animals , Autoanalysis , Chromatography, High Pressure Liquid , Dogs , Estrogens/blood , Evaluation Studies as Topic , Ibuprofen/blood , Indicators and Reagents
5.
J Anal Toxicol ; 11(2): 70-4, 1987.
Article in English | MEDLINE | ID: mdl-3573728

ABSTRACT

A method of analyzing drugs on the Toxi-Lab thin-layer chromatographic system by solid substrate room-temperature luminescence is described. Three pairs of unresolved drugs: quinine/cimetidine, caffeine/chlordiazepoxide, and phenazopyridine/lidocaine, were studied as model compounds. Their luminescence characteristics were obtained and calibration curves were found to be linear over two orders of magnitude. The effect of the nonluminescent component of each pair on the determination of the luminescent component was found to be negligible. Statistical F-tests showed that the observed differences in the slopes and intercepts of the calibration curves were due to random errors. The method was evaluated by determining quinine in urine samples at the ng level.


Subject(s)
Chromatography, Thin Layer/methods , Pharmaceutical Preparations/analysis , Caffeine/analysis , Calibration , Chlordiazepoxide/analysis , Cimetidine/analysis , Lidocaine/analysis , Luminescent Measurements , Phenazopyridine/analysis , Quinine/analysis
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