Showing papers by "Joke A. Bouwstra published in 2004"
TL;DR: It is suggested that elastic vesicle material can rapidly enter the deeper layers of the SC and can reach almost the SC-viable epidermal junction and the distribution profile of ketorolac in the deeper SC layers was, however, different from that of the vesicles.
111 citations
TL;DR: The small- and wide-angle X-ray diffraction results of the present study show for the first time that synthetic lipid mixtures, containing only three synthetic ceramides, reflect to a high extent the SC lipid organization.
73 citations
TL;DR: It is demonstrated that the CER3 to SigmaCERIV ratio affects the formation of the 13-nm lamellar phase and that the optimal ratio depends on the presence of FFA.
65 citations
TL;DR: Both pH and NaCl concentration of the donor phase are crucial on the iontophoretic transport of rotigotine.
Abstract: Purpose. The aim of this study was to characterize the influence of pH and NaCl concentration on the transdermal iontophoretic transport of the dopamine receptor agonist rotigotine across human stratum corneum (HSC).
58 citations
TL;DR: Small-angle X-ray diffraction was used to examine the organization in synthetic lipid mixtures and it is shown that a gradual increase in CER1 level consistently promotes the formation of the 13 nm lamellar phase and that partial replacement of C ER1 by CER9 does not affect the phase behavior.
49 citations
TL;DR: Iontophoretic transport of rotigotine across human stratum corneum (HSC) was studied in vitro in side by side diffusion cells according to the following protocol, indicating that by means of iontophoresis, a therapeutic level of rotIGotine might be achieved with a reasonable patch size.
49 citations
TL;DR: The data strongly indicate that the fluorescence in the cuticle originates mainly from the dye of the gap and not from the surrounding epidermis, which can be used to determine penetration pathways in the skin.
37 citations
TL;DR: The proposed time-variant input models were superior to the constant input models and appropriately converged to the observed data of GRF and R-apomorphine allowing the estimation of Jss, KR, and Jpas, and in most cases, the values of tL were negligible.
Abstract: Purpose. The objective of this study was to develop a family of compartmental models to describe in a strictly quantitative manner the transdermal iontophoretic transport of drugs in vitro.
34 citations
TL;DR: The on-line diffusion cell in combination with CLSM is a promising tool to study diffusion processes of dyes in fresh unfixed skin on- line and has the potential to access deeper skin layers as well as to visualize diffusion processes in cells.
Abstract: Purpose. The purpose of the current study was to develop a new method to examine the diffusion in fresh unfixed human skin on-line.
22 citations
TL;DR: Results indicate that the iontophoretic delivery of Timolol can be accurately controlled by the applied current, and assumes a one to one in vitro/in vivo correlation theTimolol transport in vitro results in therapeutic plasma concentrations in humans with very low current densities limiting possible skin irritation.
Abstract: The objective of this study was to assess the in vitro the iontophoretic delivery of Timolol across human dermatomed skin in order to determine whether therapeutic doses of this drug can be delivered. Anodal iontophoresis of Timolol was performed by manipulating the donor vehicle and the current density. It was observed that by reducing simultaneously the competitive ions (NaCl) from 8 to 4 g/l and the pH from 7.4 to 4.7, the iontophoretic flux was significantly increased by a factor of 1.5 (669±81 μg/cm2 h). In order to simulate the situation in a transdermal patch, the iontophoretic delivery of Timolol was also studied after adding an artificial porous membrane placed between the Timolol formulation and the human dermatomed skin. No significant difference was observed in the steady state flux across the skin when an artificial membrane was added. Furthermore, a linear relationship was found between current density and steady state flux. These results indicate that the iontophoretic delivery of Timolol c...
16 citations
TL;DR: Based on in vitro studies, transdermal iontophoresis might allow the delivery of therapeutic doses of timolol and the fluxes ofTimolol across the human stratum corneum were strongly enhanced after the application of current compared with a passive diffusion.