Transdermal delivery from a lipid sponge phase—iontophoretic and passive transport in vitro of 5-aminolevulinic acid and its methyl ester
The hydrochloride salts of 5-aminolevulinic acid (ALA) and its methyl ester (m-ALA), respectively, were dissolved in a lipid sponge phase comprising monoolein, propylene glycol and aqueous buffer at concentrations of approximately 0.25% and 16% w/w m-ALA. The iontophoretic and passive delivery of AL...
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Published in | Journal of controlled release Vol. 100; no. 2; pp. 191 - 198 |
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Main Authors | , , , , , |
Format | Journal Article |
Language | English |
Published |
Amsterdam
Elsevier B.V
2004
Elsevier |
Subjects | |
Online Access | Get full text |
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Summary: | The hydrochloride salts of 5-aminolevulinic acid (ALA) and its methyl ester (m-ALA), respectively, were dissolved in a lipid sponge phase comprising monoolein, propylene glycol and aqueous buffer at concentrations of approximately 0.25% and 16% w/w m-ALA. The iontophoretic and passive delivery of ALA and m-ALA from this formulation through porcine skin in vitro were measured and compared to formulations used in clinical practice, 20% w/w ALA in Unguentum M and Metvix® (a cream containing 16% w/w m-ALA). A sponge phase with 16% w/w m-ALA showed a higher passive flux (approximately 140 nmol cm
−2 h
−1 at 5 h) but a lower iontophoretic flux (approximately 800 nmol cm
−2 h
−1 at 5 h) compared to the clinically used products but the differences are hardly significant due to large standard deviations. ALA and m-ALA in sponge phase formulation showed iontophoretic fluxes in the range 80–100 nmol cm
−2 h
−1 at 3 h, i.e. values comparable to the passive fluxes from the more concentrated vehicles. The results demonstrate that the lipid sponge phase, a thermodynamically stable liquid with amphiphilic character, may have potential as a transdermal drug delivery vehicle. |
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Bibliography: | ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-1 content type line 23 ObjectType-Article-1 ObjectType-Feature-2 |
ISSN: | 0168-3659 1873-4995 1873-4995 |
DOI: | 10.1016/j.jconrel.2004.08.025 |