Biological ion channels rely on a multi-ion transport mechanism for fast yet selective permeation of ions. The crystal structure of the KcsA potassium channel provided the first microscopic picture of this process. A similar mechanism is assumed to operate in all potassium channels, but the validity of this assumption has not been well investigated. Here, we examine the energetics of ion permea...

The available minoxidil formulations for topical application suffer with major drawback and requires repeated application. The present study was aimed to investigate the effect of microemulsions and microemulsion based hydrogel-systems (MEHs) for increased percutaneous penetration of minoxidil. Minoxidil microemulsions were developed by conventional titration method using oleic-acid as oil, twe...

Objective(s): Ketotifen fumarate (KF) is a selective and noncompetitive histamine antagonist (H1-receptor) that is used topically in the treatment of allergic conditions of rhinitis and conjunctivitis. The aim of this study was to formulate and improve an ophthalmic delivery system of KF.Ocular nanoparticles were prepared with the objective of reducing the frequency of administration and obtain...

Sol-gel modification of mesoporous alumina membranes is a very successful technique to improve gas separation performance. Due to the formed microporous top layer, the membranes show activated transport and molecular sieve-like separation factors. This paper concentrates on the mechanism of activated transport (also often referred to as micropore diffusion or molecular sieving). Based on a theo...

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 ...