PurposeAs a continuing effort to understand the mechanisms of alternating current (AC) transdermal iontophoresis and the iontophoretic transport pathways in the stratum corneum (SC), the objectives of the present study were to determine the interplay of AC frequency, AC voltage, and ...
PubMed Central
The presence of endogenous competing counterions is a main reason for the generally low efficiency of transdermal iontophoretic drug delivery. The objective of the present study was to test the hypothesis that the incorporation of an ion-exchange membrane (Ionac) in an iontophoresis system to hinder transdermal transport of these counterions can enhance ...
The mechanisms of transscleral iontophoresis have been investigated previously with small molecules in rabbit sclera. The objective of the present study was to examine transscleral iontophoretic transport of charged macromolecules across excised human sclera. Passive and 2mA iontophoretic transport experiments were ...
PubMed
The mechanisms of transscleral iontophoresis have been investigated previously with small molecules in rabbit sclera. The objective of the present study was to examine transscleral iontophoretic transport of charged macromolecules across excised human sclera. Passive and 2-mA iontophoretic transport experiments ...
... FOR Transportable and Hybrid Transportable AC Systems Submitted 11 July, 2005 BY ... FOR Transportable and Hybrid Transportable AC Systems ...
DTIC Science & Technology
Iontophoretic and electroporation transdermal delivery modes of ionic drugs have been utilized in a number of clinical and biomedical devices. However, applications of these methods have been found challenging for the delivery of many non polar and high molecular weight clinically important drugs. The main goal of the present study is to investigate whether transdermal ...
A previous in vitro constant electrical resistance alternating current (AC) iontophoresis study with human epidermal membrane (HEM) and a model neutral permeant has shown less inter- and intra-sample variability in iontophoretic transport relative to conventional constant direct current (DC) iontophoresis. The objectives of the present ...
... from the Nernst/Planck relationship describing flux enhancement of charged molecules across a membrane or skin caused by an electric field. ...
... iontophoretic transdermal transport have been investigated but are Page 7. . . 3 ... response or of a drug level in ... There are three problems that need to ...
PurposeTransport across the human nail under hydration can be modeled as hindered transport across aqueous pore pathways. As such, nail permselectivity to charged species can be manipulated by changing the ionic strength of the system in transungual delivery to treat nail diseases. The present study investigated the effects of ionic strength upon ...
The objective of the present study was to investigate the iontophoretic transport behavior across multiple membranes of different barrier properties. Spectra/Por(R) (SP) and Ionac membranes were the synthetic membranes and sclera was the biomembrane in this model study. The barrier properties of SP membranes were determined individually in passive and ...
The objective of the present study was to investigate the iontophoretic transport behavior across multiple membranes of different barrier properties. Spectra/Por� (SP) and Ionac membranes were the synthetic membranes and sclera was the biomembrane in this model study. The barrier properties of SP membranes were determined ...
... 123. Percent Complete by Mode of Transportation (ACS). Overview ... Percent Complete by Mode of Transportation (ACS). -. -. Links on this page: Page ...
Center for Food Safety and Applied Nutrition (CFSAN)
The objective was to relate the efficiency of a charged drug to carry current across the skin during iontophoresis to its structural and/or physicochemical properties. The corollary was the establishment of a predictive relationship useful to predict the feasibility of iontophoretic drug delivery, and for the selection and optimization of drug candidates for this route of ...
... The primary benefits of a TACS or HTACS system for the Military ... basis for larger scale implementation of with solar powered tactical AC systems. ...
Transungual delivery of antifungal drugs is hindered by the low permeability of human nail plates, and as such, repeated dosing over a long period of time is necessary for effective treatment. The objectives of this study were to explore the possibilities of (a) enhancing the delivery of ciclopirox (CIC) across human nail plates and (b) sustaining CIC delivery from the larger resultant drug depot ...
Transungual iontophoretic transport of model neutral permeants mannitol (MA), urea (UR), and positively charged permeant tetraethylammonium ion (TEA) across fully hydrated human nail plates at pH 7.4 were investigated in vitro. Four protocols were involved in the transport experiments with each protocol divided into stages including ...
... Extension to AC Loss Minimisation in High Temperature Superconductors ... The transport AC loss decreases more than 3 times. ...
Iontophoresis has been proposed as an alternative method to deliver drugs into and across the nail plate. However, the knowledge about the rules governing transungual iontophoretic transport numbers is still uncomplete. This work investigated the iontophoretic and passive transungual fluxes of sodium and lithium and the effect of pH ...
Transungual transport is hindered by the inherent small effective pore size of the nail even when it is fully hydrated. The objectives of this study were to determine the effects of chemical enhancers thioglycolic acid (TGA), glycolic acid (GA), and urea (UR) on transungual transport and iontophoresis efficiency. In vitro passive and ...
The present study investigated the effects of pH on nail permeability and the transport of ions such as sodium (Na) and chloride (Cl) ions endogenous to nail and hydronium and hydroxide ions present at low and high pH, which might compete with drug transport across hydrated nail plate during iontophoresis. Nail hydration and passive ...
The in vitro permeation of three diclofenac salts--diclofenac sodium (DFS), diclofenac potassium (DFP) and diclofenac diethylammonium (DFD)-across skin by both passive and iontophoretic transport were investigated. Various skin types were used as the barriers to elucidate the mechanism controlling transdermal delivery of diclofenac salts. The importance of ...
... Title : Comparison of Iontophoretic Lidocaine to EMLA Cream for Pain Reduction Prior to Intravenous Fannulation in Adults. ...
Physiological structures associated with iontophoretic paths in hairless mouse skin and two cultured skin models ("EpiDerm" by Mattek, Corp., and "SKIN2" by Advanced Tissue Sciences, Inc.) are reported. Visualization of ionic paths at current densities between 20 and 100 microA/ cm2 is accomplished by the counterdirectional transport of Fe(CN)6(4-) and ...
The aim of the work was to study in vitro, across isolated porcine sclera and across the trilayer sclera-choroid-Bruch's membrane (SCB), the effect of iontophoresis on the permeation of a 40 kDa dextran (FD-40), chosen as model compound of high molecular weight neutral drugs. In particular, the effect of vehicle composition (in terms of buffering agent and ionic strength) and current intensity ...
Poor skin permeability limits the application of peptides to the skin. Enhanced skin permeation could facilitate the development of new therapies for dermatologic and cosmeceutical applications. The aim of this study was to investigate the application of iontophoresis to the delivery of small peptide model compounds (5-aminolevulinic acid and L-alanine-L-tryptophan) across human skin. Under the ...
Iontophoresis is the movement of charged molecules in solution under applied current using pulled multi-barrel glass capillaries drawn to a sharp tip. The technique is generally non-quantitative, and to address this, we have characterized the ejection of charged and neutral species using carbon-fiber electrodes attached to iontophoretic barrels. Our results show that observed ...
The fundamental understanding of ocular drug delivery using iontophoresis is not at the same level as that for transdermal electrotransport. Research has therefore been undertaken to characterise the electrical properties of the sclera (charge, permselectivity, and isoelectric point (pI)) and to determine the basics of iontophoretic transport of model ...
Previously, transscleral and transcorneal iontophoretic delivery was studied and compared to passive delivery and intravitreal injection using nuclear magnetic resonance imaging (MRI). The objective of the present study was to employ MRI to further investigate the factors affecting transscleral iontophoretic delivery. In the present study, anodal and ...
Between 2000 and 2003 Transportable AC Systems (TACS) and Hybrids (HTACS) were developed and demonstrated to support the electrical requirements of Command Centers in the field. Primary power was provided by unbreakable, lightweight, flexible solar module...
National Technical Information Service (NTIS)
The purpose of this study was to characterize changes that occur in the iontophoretic transport of nonionic probe permeants in hairless mouse skin epidermal membrane from the anode to cathode when polystyrene sulfonate (PSS) oligomers are cotransported from the cathode to anode. The experiments were conducted with trace levels of the nonionic probe ...
Recent in vitro and in vivo studies have suggested transscleral iontophoresis as a means for non-invasive drug delivery to the eye. However, there remains a lack of information of the iontophoretic transport behavior of the sclera. The objective of the present study was to investigate the effects of permeant concentration upon transscleral ...
In June, 1971, the Cleveland Transit System received a grant contract (Project OH-06-0006) from the Department of Transportation's Urban Mass Transportation Administration to test and evaluate on three rapid transit cars an AC propulsion system developed ...
... 1. Does the totality of the preclinical and clinical data verify that DaTSCAN allows visualization of the dopamine transporter distribution within the human ...
Center for Biologics Evaluation and Research (CBER)
... SUPERCONDUCTORS, *ELECTRIC FIELDS, *ALTERNATING CURRENT ... SURFACE PROPERTIES, THINNESS, SCALAR FUNCTIONS, LOSSES ...
