The objective of this study was to investigate the effect of modulated current application using iontophoresis- and microneedle-mediated delivery on transdermal permeation of ropinirole hydrochloride. AdminPatch® microneedles and microchannels formed by them were characterized by scanning electron microscopy, dye staining and confocal microscopy. In vitro permeation studies were carried out usi...

Multidrug-resistance (MDR) in cancer cells is often associated with marked changes in the membrane cholesterol levels. To assess the cholesterol-dependence of MDR modulator efficiency in terms of the drug-membrane interactions, the ability of 5 MDR-modulators to induce the leakage of Sulphan blue through anionic liposomes was quantified at various mole fractions x(chol) of cholesterol (0-0.42)....

Skin irritation and contact allergies are skin disorders common to hairdressers. The predominant oxidative hair dye components, such as p-phenylenediamine (PPD) and aminophenol isomers, can cause contact dermatitis. Use of protective gloves can prevent dermal contact with skin irritants. This study investigates the permeation behaviors of p-aminophenol (PAP), m-aminophenol (MAP), o-aminophenol ...

We investigated the effects of lasers irradiation on the exposed dentinal tubule. Human tooth specimens with exposed dentinal tubule orifices were used. Three types of lasers (CO(2) laser, Er:YAG laser and Ga-Al-As laser) were employed. The parameters were 1.0 W in continuous-wave mode with an irradiation time of 30 s for the CO(2) laser, 30 mJ in continuous-wave mode with an irradiation time o...

We investigated the phenomena of antimicrobial peptides (AMPs) directly attacking the cytoplasmic membranes of Escherichia coli spheroplasts. We developed a procedure for fluorescence recovery after photobleaching to examine dye leakage through bacterial membranes as AMPs in solution bound to the membranes. We found that the AMP binding did not increase the apparent membrane area of a spheropla...

Nonjunctional membrane in many cells contains connexin gap junction hemichannels (or connexons) that can open to allow permeation of small molecules. Opening of Cx43 hemichannels is infrequent in normal extracellular Ca(2+) and enhanced by low Ca(2+), positive membrane potentials, and dephosphorylation of critical residues. Here we report that lowering intracellular redox potential increases Cx...

Marked increase in cell permeability ascribed to open connexin (Cx)43 hemichannels is induced by metabolic inhibition (MI) of cortical astrocytes in culture, but the molecular mechanisms are not established. Dephosphorylation and/or oxidation of Cx43 hemichannels was proposed as a potential mechanism to increase their open probability. We now demonstrate that MI increases the number of hemichan...

Individual neurons in the developing nervous system can be visualized by the targeted delivery of a fluorophore. In this article, we describe a method for introducing a fluorescent dye via iontophoresis into retinal ganglion cell (RGC) axons in albino Xenopus laevis tadpoles. Iontophoresis is the enhanced permeation of molecules across biological membranes under the influence of an electrical f...

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 ...

the purpose of this work was to study the effect of various permeation enhancers on the permeation of salbutamol sulphate (ss) buccal patches through buccal mucosa in order to improve the bioavailability by avoiding the first pass metabolism in the liver and possibly in the gut wall and also achieve a better therapeutic effect. the influence of various permeation enhancers, such as dimethyl sul...