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Biomedical subjects

I Csóka

Publications and source records attributed to I Csóka.

5 recordsLinked to original sources
PubMed2004

In vitro and in vivo percutaneous absorption of topical dosage forms: case studies.

This article evaluated the influence of vehicle compositions on topical drug availability. In vitro drug release and in vivo experiments were performed in case of the hydrophilic ketamine hydrochloride and the lipophilic piroxicam. Ketamine hydrochloride is a NMDA receptor antagonist that has been useful for anesthesia and analgesia. The study of transdermal ketamine delivery is a novelty, because nobody has investigated the hypnotic effects of ketamine after this administration route. In vitro measurements gave a good basis for screening among the developed products. The physiological changes after ketamine administration showed, that there were significant differences among the parameters tested (breathing rate, duration of sleep) from the developed products (hydrogel, lyotropic liquid crystal and o/w cream) compared to the reference product (Carbopol gel). The in vivo feedback for piroxicam was the measurement of the anti-inflammatory activity by edema inhibition percentage. Significant differences were measured in case of the developed systems compared to the reference.

Administration, Cutaneous↗
PubMed2000

[Investigation of ambiphilic creams. II. Structural stability].

Ambiphile creams containing white petrolatum, cetylstearyl-alcohol, Emulgator BTO and distilled water were investigated. The elements of the study of structure-stability were as follows: evaporation of water-phase, mechanical stability of structure and its heatstability. A multiplicative function was found between the loss of mass of creams and the evaporation time. The viscosity vs. temperature function is a two-steps process, it can be divided to a section before melting and an other section after it. Decreasing viscosity under shearing time can be characterized by a logarithmic equation.

Drug Stability↗
PubMed2000

[Factors influencing liberation of drug from semisolid dosage forms].

Liberation of salicylic acid--as a model active agent--was investigated from white petrolatum, creams w/o and o/w types and hydrogels. Active agent was applied in suspended, dissolved forms, in inclusion complexes and solubilized state. The process of liberation was studied by a continuous through-flow method, with Hanson vertical diffusion cell. The results of experiments were evaluated by factorial design method. Increase of the concentration of salicylic acid, polarity of vehicle and solubilized state of drug increased the drug release. It was established that the partitioning released drug was the most important step of drug release. Factors changing partitioning influenced the liberation to the highest degree.

Delayed-Action Preparations↗
PubMedDate not supplied

[Liberation of active agents from coherent emulsions].

Drug release from coherent emulsions containing high water concentration (50-80 w/w%) was studied. Composition of coherent systems was as follows: self-emulsifying wax and preserved water. Griseofulvin was applied as active agent in suspended form. The liberation experiments were carried out with Hanson vertical diffusion cell, acceptor phase was distilled water, membrane was celophane one. It was established that the time course of liberation of griseofulvin from coherent emulsions can be characterized with a multiplicative function and the exponent of this function is about 0.5. The quantity of released drug increased linearly with the water content and it decreased exponentially with the viscosity of coherent emulsions.

Delayed-Action Preparations↗