Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
2487450 | Journal of Pharmaceutical Sciences | 2008 | 13 Pages |
Abstract
The porosity (ε), the tortuosity (Ï), and the hindrance factor (H) of the aqueous pore channels located in the localized transport regions (LTRs) and the non-LTRs formed in skin treated simultaneously with low-frequency ultrasound (US) and the surfactant sodium lauryl sulfate (SLS), were evaluated for the delivery of four hydrophilic permeants (urea, mannitol, raffinose, and inulin) by analyzing dual-radiolabeled diffusion masking experiments for three different idealized cases of the aqueous pore pathway hypothesis. When ε and Ï were assumed to be independent of the permeant radius, H was found to be statistically larger in the LTRs than in the non-LTRs. When a distribution of pore radii was assumed to exist in the skin, no statistical differences in ε, Ï, and H were observed due to the large variation in the pore radii distribution shape parameter (3 Ã
to infinity). When infinitely large aqueous pores were assumed to exist in the skin, ε was found to be 3-8-fold greater in the LTRs than in the non-LTRs, while little difference was observed in the LTRs and in the non-LTRs for Ï. This last result suggests that the efficacy of US/SLS treatment may be enhanced by increasing the porosity of the non-LTRs. © 2007 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 97:906-918, 2008
Keywords
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Authors
Joseph IV, Daniel Blankschtein, Robert Langer,