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Biomedical subjects

D De Rudder

Publications and source records attributed to D De Rudder.

8 recordsLinked to original sources

Chemical and physicochemical characterization of petrolatums used in eye ointment formulations.

Petrolatums from different manufacturers were characterized by viscosity measurements, oil number and ratio of low to high mol. wt components (capillary gas chromatography). Viscosity measurements and oil numbers of original materials did not correlate with the viscosity of the processed material in eye ointments. The ratio of high carbon number components to the low carbon number components was a reliable predictor for the viscosity of the formulation.

Chemical Phenomena↗

Kinetics of Pseudomonas aeruginosa adhesion to 304 and 316-L stainless steel: role of cell surface hydrophobicity.

Fifteen different isolates of Pseudomonas aeruginosa were used to study the kinetics of adhesion to 304 and 316-L stainless steel. Stainless steel plates were incubated with approximately 1.5 X 10(7) CFU/ml in 0.01 M phosphate-buffered saline (pH 7.4). After the plates were rinsed with the buffer, the number of adhering bacteria was determined by a bioluminescence assay. Measurable adhesion, even to the electropolished surfaces, occurred within 30 s. Bacterial cell surface hydrophobicity, as determined by the bacterial adherence to hydrocarbons test and the contact angle measurement test, was the major parameter influencing the adhesion rate constant for the first 30 min of adhesion. A parabolic relationship between the CAM values and the logarithm of the adhesion rate constants (In k) was established. No correlation between either the salt aggregation or the improved salt aggregation values and the bacterial adhesion rate constants could be found. Since there was no significant correlation between the bacterial electrophoretic mobilities and the In k values, the bacterial cell surface charge seemed of minor importance in the process of adhesion of P. aeruginosa to 304 and 316-L stainless steel.

Bacterial Adhesion↗

Small scale production of total parenteral nutrition infusions.

The lay-out of a small-scale production facility for the preparation of total parenteral nutrition infusions is presented. Its concept and the configuration of the production equipment and the operational procedures are explained. The cleaning and sterilization process are also described.

Environment, Controlled↗

The sorption of nitroglycerin by infusion sets.

The sorption of nitroglycerin, from 5% glucose solution, by infusion sets was investigated under simulated perfusion conditions. Several burettes, sets and catheters were evaluated. The stability of the drug in the presence of glucose was also determined. High density polyethylene and glass proved satisfactory for its perfusion in solutions. A method for the evaluation of its uptake under simulated perfusion conditions is described.

Adsorption↗

The stability and blanching efficiency of some Betnelan-V cream dilutions.

In this study Betnelan-V cream was diluted with Beeler's basis and Cold cream. Cold Cream reduced the skin-blanching activity of the original cream more than Beeler's base. The stability of betamethasone-17-valerate was better in a Beeler's basis dilution than in a Cold cream dilution.

Administration, Topical↗

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↗

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↗