Showing papers in "Journal of Pharmaceutical and Biomedical Analysis in 1984"

TL;DR: Felodipine in plasma was extracted with toluene and determined by automated capillary gas chromatography with electron capture detection and the day-to-day reproducibility of the method was represented by a relative standard deviation of 5% for a felodipines concentration of 25 nmol/l.

TL;DR: In this paper, the design and rationale of some novel chiral stationary phases (CSPs) are discussed with respect to methods for determining enantiomeric purity, absolute configuration and for obtaining enantiomersically pure materials by liquid chromatography.

TL;DR: It is shown how this model can be used in describing the chromatographic retention of sample ions in so-called reversed-phase ion-pair chromatography and predicts virtually all of the phenomena that have been described in the literature on ion- Pair chromatography.

TL;DR: Endogenous plasma levels of noradrenaline and adrenaline could be quantified with a precision (RSD) of 2-4% and reaction rate constants of the post-column reactions were determined by a flow injection analysis approach.

TL;DR: In this paper, the influence on retention and detection sensitivity of the nonabsorbing counter-ion, the UV-absorbing ion and the uncharged organic modifier have been studied systematically.

TL;DR: A HPLC method has been developed for the determination of captopril, an angiotensin-converting enzyme (ACE) inhibitor, in dog plasma that was simple, selective and sensitive.

TL;DR: A review is given of the extraction and purification of biological samples by filtration through lipophilic neutral and ion-exchange dextran gels and their derivatives and the applications of Sephadex and Lipidex gels.

TL;DR: Analytical methods based on liquid chromatography are discussed for the anthraquinone glycosides, where the high selectivity of reversed-phase liquid Chromatography systems permits ready separation from their 14-hydroxy metabolites.

TL;DR: The plasma concentration-time curves suggest the hypothesis that greater absorption of the ion-pair occurs mainly in the upper region of the gastrointestinal tract.

TL;DR: The methodology based on reversed-phase ion-pair high-performance liquid chromatography should be applicable to pharmacokinetic studies on metoclopramide, when used clinically to control the gastro-intestinal side-effects of chemotherapy.

TL;DR: SEC-theory suggests that a broad molecular weight fractionation range and high linearity of the log-linear calibration plot can be achieved by the use of two packings, rather than a single 30- to 50-nm pore-size packing with a wide psd.

TL;DR: An alternative to the well known reversed-phase separations on chemically-bonded phases has been developed based on a dynamic modification of bare silica with long chain quaternary ammonium ions, which results in a high degree of reproducibility of the selectivity between solutes.

TL;DR: The usefulness of the standardized analysis strategy previously described for the determination of basic drugs in pharmaceutical dosage forms is evaluated and it is shown that it is not necessary for the analyte and internal standard to be structurally similar.

TL;DR: The human urinary metabolism of two pyrazolone derivatives, morazone and famprofazone, has been investigated and metabolism of the metabolites p-hydroxymoraz one and phenazone-4-carboxylic acid led to the formation of methamphetamine.

TL;DR: A sensitive, specific and reproducible high-performance liquid chromatography procedure using normal phase is described for the simultaneous determination of albendazole, albendedazole sulphoxide and albENDazole sulphone in sheep plasma, with mebendrazole as an internal standard.

TL;DR: Alkylation, acylation, silylation, and other derivatization reactions applied to the gas chromatographic analysis of drugs in biological matrices are reviewed in this paper.

TL;DR: A fully-automated liquid chromatograph based on alternated pre-column enrichment technique has been developed for routine drug monitoring of body fluids using a column switching technique.

TL;DR: The results indicate that the conformational change of one of the three optically active centres of the chiral selector strongly affects its enantioselectivity for certain types of compound.

TL;DR: A new procedure is described for the selective determination of drugs containing a 1,2-diphenolic moiety based upon the measurement of difference absorbance between two equimolar solutions of the drug in pH 7 phosphate buffer.

TL;DR: The advantages of microbore columns for trace analysis by liquid chromatography are identified, with reference to on-column enrichment techniques performed on analytical micro-columns.

TL;DR: Methods for sample introduction, capillary column fabrication, and on-column detection, and a new cross-linked polymer stationary phase coating (based on similar coatings for capillary gas chromatography) are discussed.

TL;DR: This paired-ion high-performance liquid chromatographic method was applied in pharmacokinetic studies following 24-h infusion of high-dose MTX in four patients during two successive treatments and observed a stepwise increase in the plasma concentrations of both MTX and its metabolite was observed during the second MTX infusion.

TL;DR: The two most commonly used spectrometric methods for the determination of the phosphorus content of human bile are compared and data obtained by both methods have been used to calculate lithogenic index values.

TL;DR: A test model is described for the determination of the dissolution rate of the vasodilator, felodipine, a derivative of dihydropyridine that is practically insoluble in water, which is correlated to such bioavailability parameters as maximum plasma concentration and total area under the plasma concentration-time curve.

TL;DR: The spectral assignations of all the main resonances in the 13C nuclear magnetic resonance spectra in DMSO-d6 or D2O are presented and reviewed for ten of the principal tetracyclines in therapeutic use.

TL;DR: The use of BDTA as an internal standard allowed a direct, precise and accurate determination of cetylpyridinium and benzethonium chlorides, either as pure samples or in dosage forms, in the concentration range 0.05-2 mg/ml.