The Experts below are selected from a list of 2973 Experts worldwide ranked by ideXlab platform

James W. Ayres - One of the best experts on this subject based on the ideXlab platform.

  • Transmucosal, Oral Controlled-Release, and Transdermal Drug Administration in Human Subjects: A Crossover Study with Melatonin
    Journal of Pharmaceutical Sciences, 1997
    Co-Authors: L. Benes, B. Claustrat, F. Horriere, M. Geoffriau, J. Konsil, Keith A. Parrott, G. Degrande, R.l. Mcquinn, James W. Ayres
    Abstract:

    The effect of oral controlled-release (CR), oral transmucosal (buccal; TMD) and Transdermal (TDD) Drug delivery systems on plasma concentrations of melatonin (MT) and its principal metabolite in human subjects using a crossover, single dose design was evaluated. Twelve adult male volunteers participated in the study and received all three dosage forms on three separate occasions. All patch dosage forms were removed after 10 h of wear. Plasma concentrations of the parent Drug and its metabolite, 6-sulfatoxymelatonin (MT6s) were measured by radioimmunoassay. Between-subject plasma concentrations of MT were very variable following both oral CR and TDD. Use of the oral CR system gave plasma MT profiles in some subjects that were initially similar to physiological levels, but then differed substantially from physiological in the rate of MT offset; in a few subjects, plasma MT levels remained consistently much below normal nocturnal physiological levels. Also, the ratio of metabolite to parent Drug by the oral CR route was many times greater than physiological. TDD resulted in a significant delay in systemic Drug levels and a gradual decline in Drug delivery after patch removal, possibly due to deposition of melatonin in the skin. TDD failed to simulate the physiological plasma profile of MT (rapid achievement of steady-state blood levels and rapid decline after removal of the patch; i.e., so-called "square-wave" profile). TMD provided prompt systemic Drug levels with less variability than oral CR or TDD delivery. Also, plasma MT levels fell promptly and rapidly after removal of the patch. No indication of mucosal deposition was observed. TMD was able to mimic the physiological plasma profiles of both MT and its principal metabolite.

Hyungil Jung - One of the best experts on this subject based on the ideXlab platform.

  • dissolving microneedles for Transdermal Drug Administration prepared by stepwise controlled drawing of maltose
    Biomaterials, 2011
    Co-Authors: Hyungil Jung
    Abstract:

    Dissolving microneedles, three-dimensional polymer structures with microscale cross-sectional dimensions, have been introduced as a means of safe Transdermal Drug delivery. Most dissolving microneedles have been fabricated using a traditional micro-casting method that cures biopolymers within three-dimensional mold, nevertheless, repeated molding process may cause damage to encapsulated Drugs, a critical hurdle for clinical application. Here, we describe the stepwise controlled drawing technique that can directly fabricate dissolving microneedle from maltose by precise controlling the drawing time and the viscosity of the maltose. Controlled drawing shaped the particular sharp-conical microneedles of 1200 μm length with tip diameter of 60 μm, and dissolved within 20 min in-vivo after inserting to the skin. This technique surpasses the limitations of micro-casting for dissolving microneedle. Furthermore, Transdermal delivery of impermeable hydrophilic molecules such as ascorbic acid-2-glucoside and niacinamide was confirmed as inhibition of cutaneous hypermelanosis. We anticipate that controlled drawing technique will be suitable to design dissolving microneedles for use in minimally invasive transcutaneous Drug delivery to patients.

L. Benes - One of the best experts on this subject based on the ideXlab platform.

  • Transmucosal, Oral Controlled-Release, and Transdermal Drug Administration in Human Subjects: A Crossover Study with Melatonin
    Journal of Pharmaceutical Sciences, 1997
    Co-Authors: L. Benes, B. Claustrat, F. Horriere, M. Geoffriau, J. Konsil, Keith A. Parrott, G. Degrande, R.l. Mcquinn, James W. Ayres
    Abstract:

    The effect of oral controlled-release (CR), oral transmucosal (buccal; TMD) and Transdermal (TDD) Drug delivery systems on plasma concentrations of melatonin (MT) and its principal metabolite in human subjects using a crossover, single dose design was evaluated. Twelve adult male volunteers participated in the study and received all three dosage forms on three separate occasions. All patch dosage forms were removed after 10 h of wear. Plasma concentrations of the parent Drug and its metabolite, 6-sulfatoxymelatonin (MT6s) were measured by radioimmunoassay. Between-subject plasma concentrations of MT were very variable following both oral CR and TDD. Use of the oral CR system gave plasma MT profiles in some subjects that were initially similar to physiological levels, but then differed substantially from physiological in the rate of MT offset; in a few subjects, plasma MT levels remained consistently much below normal nocturnal physiological levels. Also, the ratio of metabolite to parent Drug by the oral CR route was many times greater than physiological. TDD resulted in a significant delay in systemic Drug levels and a gradual decline in Drug delivery after patch removal, possibly due to deposition of melatonin in the skin. TDD failed to simulate the physiological plasma profile of MT (rapid achievement of steady-state blood levels and rapid decline after removal of the patch; i.e., so-called "square-wave" profile). TMD provided prompt systemic Drug levels with less variability than oral CR or TDD delivery. Also, plasma MT levels fell promptly and rapidly after removal of the patch. No indication of mucosal deposition was observed. TMD was able to mimic the physiological plasma profiles of both MT and its principal metabolite.

Norihisa Miki - One of the best experts on this subject based on the ideXlab platform.

  • formation of polymer microneedle arrays using soft lithography
    Journal of Micro-nanolithography Mems and Moems, 2011
    Co-Authors: Yoshimichi Ami, Hiroto Tachikawa, Naoki Takano, Norihisa Miki
    Abstract:

    We demonstrate the fabrication of polymer microneedle arrays using soft lithography. A photomask was designed to use Fresnel diffraction of UV light to create sharp, tapered hollows in SU-8, a negative photoresist, after development. Polymer microneedles were formed using these SU-8 structures as a mold. These polymer needles may be applicable as flexible electrodes in brain-machine interfaces because they are more likely to survive movement of the skin than conventional brittle silicon needles. Similar needles, made from medicinal substances, could be used for Transdermal Drug Administration. For these applications, the needles must be long, sharp, and stiff enough to penetrate the stratum corneum (∼20 μm in thickness) and reach the viable epidermis (200-300 μm in thickness), but must not reach the dermis, which contains sensitive nerve endings. We successfully manufactured 20×20 microneedle arrays of polydimethylsiloxane with a needle length of 200 μm. We experimentally verified that these manufactured electrodes successfully penetrated the stratum corneum of a cultured skin.

  • formation of polymer microneedle arrays using soft lithography
    Journal of Micro-nanolithography Mems and Moems, 2011
    Co-Authors: Yoshimichi Ami, Hiroto Tachikawa, Naoki Takano, Norihisa Miki
    Abstract:

    We demonstrate the fabrication of polymer microneedle ar- rays using soft lithography. A photomask was designed to use Fresnel diffraction of UV light to create sharp, tapered hollows in SU-8, a nega- tive photoresist, after development. Polymer microneedles were formed using these SU-8 structures as a mold. These polymer needles may be applicable as flexible electrodes in brain-machine interfaces because they are more likely to survive movement of the skin than conventional brittle silicon needles. Similar needles, made from medicinal substances, could be used for Transdermal Drug Administration. For these applications, the needles must be long, sharp, and stiff enough to penetrate the stratum corneum (∼20 μm in thickness) and reach the viable epidermis (200-300 μm in thickness), but must not reach the dermis, which contains sensitive nerve endings. We successfully manufactured 20×20 microneedle arrays of polydimethylsiloxane with a needle length of 200 μm. We experimen- tally verified that these manufactured electrodes successfully penetrated the stratum corneum of a cultured skin. C 2011 Society of Photo-Optical Instru-

B. Claustrat - One of the best experts on this subject based on the ideXlab platform.

  • Transmucosal, Oral Controlled-Release, and Transdermal Drug Administration in Human Subjects: A Crossover Study with Melatonin
    Journal of Pharmaceutical Sciences, 1997
    Co-Authors: L. Benes, B. Claustrat, F. Horriere, M. Geoffriau, J. Konsil, Keith A. Parrott, G. Degrande, R.l. Mcquinn, James W. Ayres
    Abstract:

    The effect of oral controlled-release (CR), oral transmucosal (buccal; TMD) and Transdermal (TDD) Drug delivery systems on plasma concentrations of melatonin (MT) and its principal metabolite in human subjects using a crossover, single dose design was evaluated. Twelve adult male volunteers participated in the study and received all three dosage forms on three separate occasions. All patch dosage forms were removed after 10 h of wear. Plasma concentrations of the parent Drug and its metabolite, 6-sulfatoxymelatonin (MT6s) were measured by radioimmunoassay. Between-subject plasma concentrations of MT were very variable following both oral CR and TDD. Use of the oral CR system gave plasma MT profiles in some subjects that were initially similar to physiological levels, but then differed substantially from physiological in the rate of MT offset; in a few subjects, plasma MT levels remained consistently much below normal nocturnal physiological levels. Also, the ratio of metabolite to parent Drug by the oral CR route was many times greater than physiological. TDD resulted in a significant delay in systemic Drug levels and a gradual decline in Drug delivery after patch removal, possibly due to deposition of melatonin in the skin. TDD failed to simulate the physiological plasma profile of MT (rapid achievement of steady-state blood levels and rapid decline after removal of the patch; i.e., so-called "square-wave" profile). TMD provided prompt systemic Drug levels with less variability than oral CR or TDD delivery. Also, plasma MT levels fell promptly and rapidly after removal of the patch. No indication of mucosal deposition was observed. TMD was able to mimic the physiological plasma profiles of both MT and its principal metabolite.