Transdermal iontophoretic delivery of ketoprofen in cadaver skin and healthy volunteers was examined. In vitro anodic and cathodic iontophoresis (0.5 mA/cm2, 3 h) of ketoprofen (75 mg/ml) resulted in equivalent intracutaneous ketoprofen permeation (232.1 ± 27.1 vs. 275.0 ± 141.0 μg/cm2, respectively), which in turn was higher than passive intracutaneous uptake of ketoprofen (40.7 ± 42.1 μg/cm2). In contrast, only cathodic iontophoresis resulted in transcutaneous ketoprofen permeation across cadaver skin, under these conditions. The in vitro study was then repeated to achieve transcutaneous permeation of ketoprofen at clinical iontophoretic parameters (0.28 mA/cm2, 40 min) by increasing drug concentration to 300 mg/ml. No stereo-selective permeation of R- and S-ketoprofen enantiomers was observed in vitro. In humans, cathodic iontophoresis of 300 mg/ml ketoprofen (0.28 mA/cm2, 40 min) was performed at the wrist. Ketoprofen was detected at 40 min (0.88 ± 0.42 μg/ml) from the forearm veins of the ipsilateral arm. Urinary excretion of ketoprofen totaled 790 ± 170 μg at 16 h post iontophoresis. This investigation is the first to clearly demonstrate transcutaneous iontophoresis of an antiinflammatory agent in humans utilizing a commercially cleared iontophoretic device. The investigation also adds to the very limited number of publications in the area of iontophoretic delivery of drugs to humans.

Interest within the healthcare profession in transdermal delivery of pharmaceuticals through passive, mechanical (phonophoresis) or electromotive (iontophoresis) forces has increased significantly throughout the past decade. The current review will examine the histology and cellular biology of the integument system as related to regulation of transcutaneous delivery of pharmaceutics, and examine currently accepted mechanism(s) of iontophoretic delivery. Additionally, a survey of current iontophoretic devices and electrodes available within the U.S. market, and the limitations of current technology will be presented. Experimental research supporting the use of iontophoresis for local delivery of pharmaceuticals will also be presented in conjunction with the outcomes of clinical investigations where iontophoresis was utilized for the local delivery of these pharmaceuticals. Topic areas to be covered within this section include iontophoresis of antibiotics into integument wounds, local anesthetics, and steroidal and nonsteroidal anti- inflammatory drugs. Finally, an examination of the benefits of combining various forces to enhance transcutaneous drug delivery and future direction(s) of research within this field will be discussed. The purpose of the present review is to provide both researchers and clinical practitioners with an objective basis for the current use of iontophoresis in rehabilitation medicine.

Background and Purpose. Iontophoresis is a process that uses bipolar electric fields to propel molecules across intact skin and into underlying tissue. The purpose of this study was to describe and experimentally examine an iontophoresis drug delivery model. Subjects and Methods. A mechanistic model describing delivery was studied in vitro using agarose gels and was further tested in vivo by evaluation of cutaneous vasoconstriction following iontophoresis in human volunteers. Results. In vitro cathodic iontophoresis at 4 mA and 0.1 mA each delivered dexamethasone/dexamethasone phosphate (DEX/DEX-P) from a 4-mg/mL donor solution to a depth of 12 mm following a 40 mA·minute stimulation dosage. Delivery of DEX/DEX-P to at least the depths of the vasculature in humans was confirmed by observation of cutaneous vasoconstriction. This cutaneous vasoconstriction was longer lasting and greater in magnitude when using low-current, long-duration (∼0.1 mA) iontophoresis compared with equivalent dosages delivered by higher-current, shorter-duration (1.5-4.0 mA) iontophoresis. Discussion and Conclusion. From data gathered with the gel model, the authors developed a model of a potential mechanism of drug depot formation following iontophoresis. The authors believe this drug depot formation to be due to exchange of drug ions for chloride ions as the ionic current carriers. Furthermore, diffusion, not magnitude of current, appears to govern the depth of drug penetration. Although the authors did not address the efficacy of the drug delivered, the results of human experiments suggest that current magnitude and duration should be considered as factors in treating musculoskeletal dysfunctions with iontophoresis using DEX/DEX-P at a concentration of 4 mg/mL. [Anderson CR, Morris RL, Boeh SD, et al. Effects of iontophoresis current magnitude and duration on dexamethasone deposition and localized drug retention.

No description available.

Interest within the healthcare profession in transdermal delivery of pharmaceuticals through passive, mechanical (phonophoresis) or electromotive (iontophoresis) forces has increased significantly throughout the past decade. The current review will examine the histology and cellular biology of the integument system as related to regulation of transcutaneous delivery of pharmaceutics, and examine currently accepted mechanism(s) of iontophoretic delivery. Additionally, a survey of current iontophoretic devices and electrodes available within the U.S. market, and the limitations of current technology will be presented. Experimental research supporting the use of iontophoresis for local delivery of pharmaceuticals will also be presented in conjunction with the outcomes of clinical investigations where iontophoresis was utilized for the local delivery of these pharmaceuticals. Topic areas to be covered within this section include iontophoresis of antibiotics into integument wounds, local anesthetics, and steroidal and nonsteroidal anti-inflammatory drugs. Finally, an examination of the benefits of combining various forces to enhance transcutaneous drug delivery and future direction(s) of research within this field will be discussed. The purpose of the present review is to provide both researchers and clinical practitioners with an objective basis for the current use of iontophoresis in rehabilitation medicine.

Study Design: Controlled laboratory study. Objectives: To determine the time course of dexamethasone sodium phosphate (Dex-P) iontophoresis delivery to underlying tissues using microdialysis. Background: The efficacy of iontophoresis at delivering Dex-P through the skin is unknown in humans because of the lack of minimally invasive measurement techniques. Methods: Sixty-four healthy male participants (age = 24.4 ± 3.3 yrs, height = 71.8 ± 2.5 in, weight = 181.8 ± 26.1 lbs) were randomly assigned into one of six groups: 1) 1 mA current, 1 mm probes depth ; 2) 1 mA current, 4 mm probes depth; 3) 2 mA current, 1 mm probes depth; 4) 2 mA current, 4 mm probes depth; 5) in vivo retrodialysis; and 6) skin perfusion flowmetry. Microdialysis probes assess the combined recovery (Dextotal) of Dex-P, dexamethasone (Dex) and its metabolite. In vivo calibration of the microdialysis probes occurred via retrodialysis. Laser Doppler flowmetry assessed skin perfusion. Results: There was no difference of Dextotal between current intensities (P = 0.99) but a greater amount of Dextotal was recovered by the 1 mm probe (P < 0.0001) compared to the 4 mm probe. Peak means for the 1 and 2 mA at 1 mm were 10.8 ± 8.1 and 7.7 ± 5.5 μg/ml and at 4mm being 2.0 ± 0.8 and 1.3 ± 0.9 μg/ml, respectively. Skin perfusion rapidly increased during both current intensity treatments, but significantly decreased before the conclusion of the 1 mA treatment (P < 0.0001). Peak skin perfusion was 741.4 ± 408.7% and 711.6 ± 260.8% baseline for 1 and 2 mA intensities, respectively. Conclusion: Iontophoresis delivery of Dex-P was successful measured in vivo through human skin. Significant concentrations of Dextotal were found regardless of current intensity. Though current induced vasodilation occurred, it did not significantly affect the tissue accumulation of Dextotal.

No / This work evaluated the in vitro transdermal iontophoretic delivery of tritiated estradiol from ultradeformable liposomes compared with saturated aqueous solution (control). Effects of current density and application time on tritium exchange with water were also determined. Penetration studies used three Protocols. Protocol I involved occluded passive steady state estradiol penetration from ultradeformable liposomes and control. The effect of current densities on drug penetration rates was also assessed (Protocol II). In Protocol III, three consecutive stages of drug penetration (first passive, iontophoresis and second passive) through the same human epidermal membranes were monitored. Such an experimental design investigated the possible effect of high current density (0.8 mA/cm2) on skin integrity. The tritium exchange study showed that extent of exchange correlated well with current density and time of application, with some shielding of estradiol by the liposomal structure. Liposomes enhanced estradiol passive penetration after occlusion. Protocol II showed that estradiol flux increased linearly with current density, although being delivered against electroosmotic flow. In Protocol III, reduction in flux of the second passive stage to near that of the first reflected a reversibility of the structural changes induced in skin by current.

No / Electrically assisted skin delivery of liposomal estradiol; phospholipid as damage retardant.

No description available.

No description available.