a broad range of per-meation events from femtoseconds to minutes in time scale and sub-angstrom to millimeter in space were discussed. A main message in the Perspectives was to explore each discipline to expand its limitation, such that different levels of knowledge in a hierarchy of ion permeation events are integrated. Here, we propose another approach from a mesoscopic point of view. Electro...

Ion transports through ion channels, biological nanopores, are essential for life: Living cells generate electrical signals by utilizing ion permeation through channels. The measured current-voltage (i-V) relations through most ion channels are sublinear, however, its physical meaning is still elusive. Here we calculated the i-V curves through anion-doped carbon nanotubes, a model of an ion cha...

In the present study, chitosan membranes capable of imitating permeation characteristics of diclofenac diethylamine across animal skin were prepared using cast drying method. The effect of concentration of chitosan, concentration of cross-linking agent (NaTPP), crosslinking time was studied using Taguchi design. Taguchi design ranked concentration of chitosan as the most important factor influe...

The aims of this study were to investigate the utility of solid microneedle arrays (150 µm in length) in enhancing transdermal delivery of peptides and to examine the relationship between peptide permeation rates and D2O flux. Four model peptides were used (Gly-Gln-Pro-Arg [tetrapeptide-3, 456.6 Da], Val-Gly-Val-Ala-Pro-Gly [hexapeptide, 498.6 Da], AC-Glu-Glu-Met-Gln-Arg-Arg-NH2 [acetyl hexapep...

Insulin-loaded microemulsions for transdermal delivery were developed using isopropyl myristate or oleic acid as the oil phase, Tween 80 as the surfactant, and isopropyl alcohol as the cosurfactant. The pseudoternary phase diagrams were constructed to determine the composition of microemulsions. The insulin permeation flux of microemulsions containing oleic acid as oil phase through excised mou...

promethazine hydrochloride, a 5-ht3 antagonist is a powerful antiemetic drug with an oral bioavailability of 25% due to extensive hepatic first pass metabolism and is extremely bitter in taste. to overcome the above draw backs, the present study was carried out to formulate and evaluate fast dissolving taste masked wafers of promethazine hydrochloride for sublingual administration. taste maskin...

A theoretical model of gas permeation in polydimethylsiloxane (PDMS) is conducted for two prior works involving MEMS sensors and actuators. The issue for modeling a sensor is about using PDMS slabs to replace Pyrex glass as the packaging substrate for bulk-micromachined pressure sensors. The leakage pressure due to gas permeation in PDMS reveals the time-varying behavior of exponential decay. T...

This study investigates the effects of two surfactants (one anionic and one non-ionic) and controlled modifications in temperature (298-323K) on the permeation of two structurally similar compounds through a silicone membrane using a Franz diffusion cell system. In all cases the presence of an anionic surfactant, namely sodium dodecyl sulphate (SDS), reduced the permeation of both compounds (me...

many properties of chemicals depend on their stereochemistry. among these, the effects of stereoisomerism on percutaneous absorption of drugs are not well studied. we have previously shown that permeation of tretinoin and isotretinoin (two geometric isomers) through hydrophilic enhancers-treated rat skin is stereoselective. as, depending on their lipophilicity, penetration enhancers can change ...

in this work we sought to determine whether vesicles (liposomes/niosomes) were able to enhance finasteride concentration in the dermis layer, including the pilosebaceous units (psu). such enhancement could be beneficial in the treatment of some androgen-related skin disorders. hamster flank skin was used to study  3hfinasteride permeation via vesicles and a hydroalcoholic solution (ha). the dru...