Search results for "permeation"
showing 10 items of 274 documents
Galantamine delivery on buccal mucosa: permeation enhancement and design of matrix tablets
2009
The most important feature in transbuccal drug delivery is the low drug passage through the buccal mucosa. In our previous work we demonstrated the aptitude of Galantamine to penetrate the buccal tissue. The collected data suggested that Galantamine passively crosses the membrane, but the calculated Js and Kp values showed that the drug amount that crosses the membrane wasn’t sufficient to assure blood therapeutic level. So, in this study, ex vivo permeation tests, using porcine buccal mucosa, were performed in presence of physical or chemical enhancers. No significant differences in penetration rate were observed using chemical enhancers as sodium dehydrocholate, EDTA disodium salt and tri…
Influence of Chemical Enhancers and Iontophoresis on the In Vitro Transdermal Permeation of Propranolol: Evaluation by Dermatopharmacokinetics
2018
[EN] The aims of this study were to assess, in vitro, the possibility of administering propranolol transdermally and to evaluate the usefulness of the dermatopharmacokinetic (DPK) method in assessing the transport of drugs through stratum corneum, using propranolol as a model compound. Four chemical enhancers (decenoic and oleic acid, laurocapram, and R-(+)-limonene) and iontophoresis at two current densities, 0.25 and 0.5 mA/cm(2) were tested. R-(+)-limonene, and iontophoresis at 0.5 mA/cm(2) were proven to be the most efficient in increasing propranolol transdermal flux, both doubled the original propranolol transdermal flux. Iontophoresis was demonstrated to be superior than the chemical…
Human buccal mucosa as an innovative site of drug delivery.
2009
The authors review the ultra-structural aspects and permeability features of normal human oral mucosa, after having recently tested and used it as a new site of systemic drug delivery. The pertinent scientific literature from 1975 through 2009 has been analysed and discussed. Buccal epithelium is a relatively permeable, robust non-keratinized tissue and blood vessels drain directly into the jugular vein; due to its particular features, it has been of increasing interest to researchers as an alternative site of drug administration. The review describes the structure and function of the buccal mucosa, the rationale for transbuccal drug delivery and the main transmucosal drug delivery systems.…
Amorphous Ropinirole-Loaded Mucoadhesive Buccal Film: A Potential Patient-Friendly Tool to Improve Drug Pharmacokinetic Profile and Effectiveness
2020
Nowadays the therapeutic strategies to manage Parkinson&rsquo
Bipolar electrolysis for tritium recovery from weakly active tritiated water
2001
Abstract Detritiation facilities produce low activity tritiated water from which tritium cannot be recovered. Bipolar electrolysis, based on the electrochemical permeation of hydrogen and its isotopes through Pd–Ag alloy membranes, allows tritiated water enrichment together with negligible gaseous tritium release. Our purpose is to enrich water from 500 Ci/l (1.85×1013 Bq/l) to more than 2000 Ci/l (7.40×1013 Bq/l). We first describe the principle of bipolar electrolysis and its application to isotopic enrichment. The experimental part of this work consists of the determination of the isotopic separation factors. From these experimental values, we simulated the working of an operational cell…
Barrier properties of anti-gas military garments, considering exposure to gas organic compounds
2020
The problems of determining the protective properties of barrier materials used for the production of body surface protection products of an isolative type are very actual. These garments are expected to have long-term resistance against permeation of toxic substances. The paper deals with the study of the effect of organic solvent vapours on the changes in protective properties of selected anti-gas protective garments commonly used by the North Atlantic Treaty Organization armed forces. Permeation measurements of selected gases with integral permeameter were performed to verify their barrier properties, surface changes after exposure to selected solvents by using a 3D optical profilometer,…
Protecting emergency workers and armed forces from volatile toxic compounds: Applicability of reversible conductive polymer-based sensors in barrier …
2019
International audience; Barrier materials have wide applicability in both professional (military, medical, industrial) and non-professional(leisure and sports) fields. This paper focuses on the preparation of real conductive polymer (CP) sensors, for thestudy of the permeation of volatile toxic compounds through barrier materials. Use of such a CP sensor can helpimprove the quality of barrier materials used in protective clothing. Several types of platforms have beenmanufactured or purchased for use as comb sensors with different electrode dimensions, and a suitable methodof applying the detection layer of conductive polymers (polyaniline and poly-pyrrole) has been developed. Prepared senso…
Application of a new dynamic transport model to predict the evolution of performances throughout the nanofiltration of single salt solutions in conce…
2018
Although many knowledge models describing the rejection of ionic compounds by nanofiltration membranes are available in literature, they are all used in full recycling mode. Indeed, both permeate and retentate streams are recycled in order to maintain constant concentrations in the feed solution. However, nanofiltration of real effluents is implemented either in concentration or diafiltration modes, for which the permeate stream is collected. In these conditions, concentrations progressively evolve during filtration and classical models fail to predict performances. In this paper, an improvement of the so called "Donnan Steric Pore Model", which includes both volume and concentration variat…
Improvement of membrane performances to enhance the yield of vanillin in a pervaporation reactor.
2014
In membrane reactors, the interaction of reaction and membrane separation can be exploited to achieve a “process intensification”, a key objective of sustainable development. In the present work, the properties that the membrane must have to obtain this result in a pervaporation reactor are analyzed and discussed. Then, the methods to enhance these properties are investigated for the photocatalytic synthesis of vanillin, which represents a case where the recovery from the reactor of vanillin by means of pervaporation while it is produced allows a substantial improvement of the yield, since its further oxidation is thus prevented. To this end, the phenomena that control the permeation of bot…
Evaluation of vapor mass transfer in various membrane distillation configurations: an experimental study
2011
Vapor mass transfer phenomena in four different membrane distillation (MD) configurations were examined through a self-built laboratory scale experimen- tal apparatus: Air Gap MD, Sweeping Gas MD, Vacuum Sweeping Gas MD and Vacuum MD. Vapor fluxes were measured and compared with those predicted by various models, showing that MD performance under usual processing conditions is severely controlled by the permeate side resistance to mass transfer.