0000000000294364
AUTHOR
David Quintanar-guerrero
Polymeric nanospheres as strategy to increase the amount of triclosan retained in the skin: passive diffusion vs. iontophoresis
The aim of this study was to evaluate the passive and iontophoretic permeation of triclosan in human skin using a triclosan solution and triclosan-loaded cationic nanospheres in order to determine which of the two strategies is more effective in allowing the deposition of triclosan within the skin. Triclosan-loaded nanospheres were prepared by the emulsification-solvent displacement technique using aminoalkyl methacrylate (Eudragit® RL 100) as polymer matrix. Nanospheres of 261.0 ± 15.1 nm with a positive surface charge (Ψz = 26.0 ± 3.2 mV) were obtained. Drug loading was 62.0 ± 1.7%. Results demonstrated that the amount of triclosan retained within the skin was significantly greater (8.5-f…
Transdermal iontophoresis of dexamethasone sodium phosphate in vitro and in vivo: effect of experimental parameters and skin type on drug stability and transport kinetics
The aim of this study was to investigate the cathodal iontophoresis of dexamethasone sodium phosphate (DEX-P) in vitro and in vivo and to determine the feasibility of delivering therapeutic amounts of the drug for the treatment of chemotherapy-induced emesis. Stability studies, performed to investigate the susceptibility of the phosphate ester linkage to hydrolysis, confirmed that conversion of DEX-P to dexamethasone (DEX) upon exposure to samples of human, porcine and rat dermis for 7 h was limited (82.2+/-0.4%, 72.5+/-4.8% and 78.6+/-6.0% remained intact) and did not point to any major inter-species differences. Iontophoretic transport of DEX-P across dermatomed porcine skin (0.75 mm thic…
Comparing metoclopramide electrotransport kinetics in vitro and in vivo.
The purpose of this work was to investigate the transdermal iontophoretic delivery of metoclopramide and to determine (i) the dependence of electrotransport on current density and drug concentration, (ii) the relative contributions of electromigration and electroosmosis and (iii) the feasibility of administering therapeutic amounts of drug, using a drug-sparing iontophoretic configuration. Iontophoretic delivery of metoclopramide (MCL) across dermatomed porcine ear skin was investigated in vitro as a function of concentration (10, 20, 40, 80 and 100mM) and current density (0.1, 0.2 and 0.3mAcm(-2)) using vertical flow-through diffusion cells. In vivo studies were performed in Wistar rats (4…
Using transdermal iontophoresis to increase granisetron delivery across skin in vitro and in vivo: effect of experimental conditions and a comparison with other enhancement strategies.
The objectives of the study were (i) to investigate the effect of experimental parameters on the iontophoretic transport of granisetron, (ii) to identify the relative contributions of electromigration (EM) and electroosmosis (EO), (iii) to determine the feasibility of delivering therapeutic amounts of drug for the treatment of chemotherapy-induced nausea and vomiting and (iv) to test the in vitro results in a simple animal model in vivo. Preliminary in vitro studies using aqueous granisetron formulations investigating the effect of drug concentration (5, 10, 20 and 40 mM) and current density (0.1, 0.2, 0.3 mA cm(-2)) were performed using porcine ear skin. As expected, cumulative delivery in…