Theoretical and experimental investigations of passive and ultrasound-enhanced transdermal drug delivery

In the initial investigation of this thesis, Fick's second law of diffusion was modified to describe both the transient, and the steady-state, transdermal transport of hydrophilic permeants through unbranched, aqueous pore channels. This new transport model, combined with dual radiolabeled diffusion experiments, was then used to separately evaluate how the porosity, the tortuosity, and the hindrance factor of the aqueous pore channels that exist in the skin varied as the extent of skin perturbation due to simultaneous treatment of the skin with low-frequency ultrasound (US) and a chemical enhancer, the surfactant sodium lauryl sulfate (SLS), and as the radius of the hydrophilic permeant delivered across the skin, were increased. This investigation revealed that the values of the hindrance factor and of the tortuosity decreased as the radius of the hydrophilic permeant increased, and that the value of the porosity of the aqueous pore channels increased as the extent of skin perturbation due to the application of US increased. This last result suggested that low-frequency US primarily enhances the transport of hydrophilic permeants by increasing the fraction of the skin surface occupied by the aqueous pore channels.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Chemical Engineering.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2007

Author dc:creator

• Kushner, Joseph, IV

Advisor dc:contributor.advisor

• Daniel Blankschtein and Robert Langer.

• Chemical Engineering.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/38980

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/38980