Premium
Comparative in vitro percutaneous penetration of 5‐aminolevulinic acid and two of its esters through excised hairless mouse skin
Author(s) -
van den Akker Johanna T.H.M.,
Holroyd J. Andrew,
Ver David I.,
Sterenborg Henricus J.C.M.,
Brown Stanley B.
Publication year - 2003
Publication title -
lasers in surgery and medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.888
H-Index - 112
eISSN - 1096-9101
pISSN - 0196-8092
DOI - 10.1002/lsm.10212
Subject(s) - stratum corneum , hairless , penetration (warfare) , in vivo , in vitro , chemistry , human skin , dermatology , biochemistry , pathology , medicine , biology , genetics , microbiology and biotechnology , operations research , engineering
Background and Objectives ALA esters have been developed to improve PpIX production in ALA–PDT, but they do not perform as well in skin as they do in cells and the bladder. Study Design/Materials and Methods The in vitro penetration across normal mouse skin of ALA and its methyl and hexyl ester was determined for different application concentrations. ALA and the esters were also applied to tape stripped skin to determine the effect of the stratum corneum. Results The penetration of ALA and the esters was higher through tape stripped skin than through normal skin ( P < 0.01), showing that the stratum corneum is an important barrier. The experiments with different application concentrations indicated that the skin penetration through normal skin and tape stripped skin is highest for ALA and lowest for the hexyl ester. Conclusions The differences in skin penetration properties could be (co‐)responsible for the finding that ALA esters do not induce substantially higher PpIX levels in in vivo skin. Lasers Surg. Med. 33:173–181, 2003. © 2003 Wiley‐Liss, Inc.