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Biomedical subjects

P Braeckman

Publications and source records attributed to P Braeckman.

At least 19 recordsLinked to original sources
PubMed1986

Quantification of ethylene chlorohydrin and ethylene glycol as potential reaction products in gas-sterilized medical-grade plastics.

A gas chromatographic procedure is described for the quantitative determinations of ethylene chlorohydrin and ethylene glycol in disposable medical-grade plastics. Both components are isolated by solvent extraction. The lower limit of detection is 1 p.p.m. of ethylene chlorohydrin and 2 p.p.m. of ethylene glycol. Propylene glycol is used as an internal standard. Ethylene oxide residues have to be removed prior to the assay.

Chemical Phenomena↗
PubMed1984

Polymorphic behaviour of chloroquine diphosphate.

The crystalline structure of two different batches of chloroquine diphosphate was studied. Differential thermal analysis showed the existence of two polymorphic modifications in one of the batches, whilst spectral analysis did not reveal any differences. This discrepancy is attributed to the fact that the second modification is formed during the transition phase when analysed by differential thermal analysis. This recrystallization process is initiated by the presence of seed material. The ratio of transition heat of both modifications is dependent on particle size and heating rate during analysis.

Chloroquine↗
PubMed1984

The rabbit as an experimental model for biopharmaceutical studies following rectal administration of theophylline.

In order to find a suitable animal model for biopharmaceutical studies after rectal application of theophylline, the pharmacokinetics of theophylline following the administration in rabbits of three different rectal preparations were examined and compared with those of the oral and i. v. route. No significant formulation related impact from the studied rectal dosage forms on the bioavailability of the drug was found. However, the unexpected rapid achievement of peak serum concentration after insertion of the suppository lacked any correlation with human experiments. It was concluded that the evaluation of rectal theophylline medication for man cannot directly be based on the data obtained from rabbits.

Administration, Oral↗
PubMed1983

Interaction of antacids with antiarrhythmics. V. Effect of aluminium hydroxide and magnesium oxide on the bioavailability of quinidine, procainamide and propranolol in dogs.

The influence of aluminium hydroxide and magnesium oxide on the oral bioavailability of quinidine, procainamide and propranolol in the dog was investigated. The administration of aluminium hydroxide with a quinidine sulfate capsule causes a significant decrease of maximal plasma concentration (Cpmax) and a shift in tmax (time to reach Cpmax). The area under the curve is not significantly decreased. Administration of magnesium oxide together with a quinidine sulfate capsule or a sustained-release preparation of quinidine bisulfate causes a significant decrease of both Cpmax and the area under the curve. A shift of tmax was observed for the conventional preparation only. The administration of aluminium hydroxide with procainamide hydrochloride diminishes only Cpmax in a significant way. Administration of magnesium oxide together with procainamide hydrochloride has no influence on the different parameters. Administration of aluminium hydroxide or magnesium oxide with propranolol hydrochloride has a significant negative influence on both the Cpmax and the area under the curve.

Aluminum Hydroxide↗
PubMed1981

Determination of plasma theophylline by straight-phase high-performance liquid chromatography: elimination of interfering caffeine metabolites.

Several authors have recently reported interference in theophylline analysis by paraxanthine (1,7-dimethylxanthine), an important metabolite of caffeine. A method for the determination of theophylline in plasma is described, eliminating caffeine and related compounds by means of straight-phase high-performance liquid chromatography. The resulting procedure is sufficiently rapid, accurate and sensitive to be applied in routine monitoring of therapeutic levels in patients as well as for pharmacokinetic purposes. Although only 0.1 ml of sample is required, concentrations as low as 0.2 mg/l can be measured with acceptable precision. A brief comparative evaluation of this procedure with a radioimmunoassay is made.

Beverages↗
PubMed1981

Drug-polymer combinations. Part 1: The preparation of sustained release drugs by combination with ion exchanging resins.

The preparation of procainamide and propranolol resinates is described. By in vivo experiments with propranolol resinate as model substance the release rate as a function of crosslinking degree and particle size is studied. An in vitro test is carried out to compare the performance as prolonged release preparation of a resinate, e.g. procainamide resinate, with the action of the pure drug and of a Durette formulation.

Delayed-Action Preparations↗
PubMed1978

Studies on the crystalline form of phenytoin.

Two crystalline forms of phenytoin were isolated and characterized by X-ray diffraction, IR spectroscopy and differential thermal analysis. The dissolution behavior of the two forms was determined in water. The crystals of needle shape (form II) were found to exhibit slower dissolution rate than the other crystal form (form I).

Chemistry, Pharmaceutical↗