Transdermal drug delivery is highly advantageous method for drug administration, yet the compact structure of stratum corneum is an effective barrier which limited the use of this route to very few drug molecules. Ultrasound enhances the permeation through the skin by altering this barrier function in a phenomenon named sonophoresis. This study aimed to evaluate the effect of variable ultrasoni...

Permeation tubes are convenient analyte sources for generating standard gas mixtures (containing, in particular, volatile organic compounds) used in the calibration of analytical instruments. For small permeation rates, corresponding to trace levels of analytes, the calibration of permeation tubes is time-consuming. The use of thermogravimetry as a means to measure rapidly the weight loss at co...

objective (s): transdermal preparations for testosterone are becoming popular because of their unique advantages such as avoidance of first-pass effect, convenience, improved bioavailability, and reduction of systemic side effects. a novel testosterone transdermal delivery system (tdds) was developed using a palm oil base called hamintm (a commercial product) and tested using in vitro and in vi...

By using molecular dynamics simulation, the dynamic behaviors of particle permeation through a four-helix-bundle model channel are studied. The interior cavity of the four-helix-bundle provides the "routes" for particle permeation. The main structural properties of the model channel are similar to those that appear in natural four-helix-bundle proteins. It is found that the interior structure o...

This paper focuses on the effects of the addition of an ionic liquid, 1-Allyl-3-butylimidazilium bis(trifluoromethane sulfonyl)imide ([ABIM]TFSI), which has a high affinity for benzene, into the poly(vinyl chloride) (PVC) membrane on the pervaporation characteristics of the removal of benzene from aqueous solutions of dilute benzene. When aqueous solutions of 100～500 ppm benzene were permeated ...

Preformulation studies on transdermal dosage forms involve liberal use of animal skin for assessing the permeation characteristics of drugs, influence of permeation enhancers, optimizing the formulation variables etc. The restricted availability of animal skin due to concerns regarding prevention of cruelty to animals has generated considerable interest in developing polymeric films for use as ...

Preformulation studies on transdermal dosage forms involve liberal use of animal skin for assessing the permeation characteristics of drugs, influence of permeation enhancers, optimizing the formulation variables etc. The restricted availability of animal skin due to concerns regarding prevention of cruelty to animals has generated considerable interest in developing polymeric films for use as ...

Potassium channels embedded in cell membranes employ gates to regulate K+ current. While a specific constriction in the permeation pathway has historically been implicated in gating, recent reports suggest that the signature ion selectivity filter located in the outer membrane leaflet may be equally important. Inwardly rectifying K+ channels also control the directionality of flow, using intrac...

FocA belongs to the formate-nitrate transporter family and plays an essential role in the export and uptake of formate in organisms. According to the available crystal structures, the N-terminal residues of FocA are structurally featureless at physiological conditions but at reduced pH form helices to harbor the cytoplasmic entrance of the substrate permeation pathway, which apparently explains...