PMID- 20634088
OWN - NLM
STAT- MEDLINE
DCOM- 20101220
LR  - 20131121
IS  - 1873-2682 (Electronic)
IS  - 1011-1344 (Linking)
VI  - 101
IP  - 1
DP  - 2010 Oct 5
TI  - Novel patch-based systems for the localised delivery of ALA-esters.
PG  - 59-69
LID - 10.1016/j.jphotobiol.2010.06.012 [doi]
AB  - In photodynamic therapy (PDT) a combination of visible light and a sensitising 
      drug causes the destruction of selected cells. Aminolaevulinic acid (ALA) has 
      been widely used in topical PDT for over 15 years. However, ALA does not possess 
      favourable physicochemical properties for skin penetration. Consequently, the 
      clearance rates for difficult to treat lesions, such as nodular basal cell 
      carcinomas are relatively low. For the first time, equimolar concentrations of 
      ALA, methyl-ALA (m-ALA) and hexyl-ALA (h-ALA) have been incorporated into a 
      bioadhesive patch-based system. In vitro penetration studies into excised porcine 
      skin revealed that ALA patches containing relatively high loadings (226.7 
      micromol cm(-2)) were associated with significantly greater tissue concentrations 
      (70.7 micromol cm(-3)) than patches containing m-ALA (16.3 micromol cm(-3)) or 
      h-ALA (17.4 micromol cm(-3)). ALA was also found to be the most efficient inducer 
      of protoporphyrin (PpIX) fluorescence in mice, in vivo (maximum mean 
      fluorescence: ALA=236.2 a.u., m-ALA=175.1 a.u., h-ALA=193.5 a.u.). However, when 
      the lipophilic hexylester was formulated in a pressure sensitive adhesive (PSA) 
      patch, significantly higher PpIX levels were achieved compared to all bioadhesive 
      systems tested. Of major importance, PSA patches containing relatively low h-ALA 
      loadings induced high PpIX levels, which were localised to the application area. 
      This study has highlighted the importance of rational selection of both the 
      active agent and the delivery system. Bioadhesive preparations containing ALA are 
      ideal for delivery to moist environments; whereas h-ALA-loaded PSA systems may 
      facilitate enhanced delivery to dry areas of skin. In addition, owing to the 
      relatively low loadings of h-ALA required in PSA patches, the costs of clinical 
      PDT may potentially be reduced.
CI  - Copyright 2010 Elsevier B.V. All rights reserved.
FAU - Morrow, Desmond I J
AU  - Morrow DI
AD  - School of Pharmacy, Queen's University Belfast, Medical Biology Centre, 97 
      Lisburn Road, Belfast BT9 7BL, UK.
FAU - McCarron, Paul A
AU  - McCarron PA
FAU - Woolfson, A David
AU  - Woolfson AD
FAU - Juzenas, Petras
AU  - Juzenas P
FAU - Juzeniene, Asta
AU  - Juzeniene A
FAU - Iani, Vladimir
AU  - Iani V
FAU - Moan, Johan
AU  - Moan J
FAU - Donnelly, Ryan F
AU  - Donnelly RF
LA  - eng
PT  - Journal Article
DEP - 20100630
PL  - Switzerland
TA  - J Photochem Photobiol B
JT  - Journal of photochemistry and photobiology. B, Biology
JID - 8804966
RN  - 0 (Esters)
RN  - 0 (Photosensitizing Agents)
RN  - 0 (Protoporphyrins)
RN  - 0 (Tissue Adhesives)
RN  - 88755TAZ87 (Aminolevulinic Acid)
SB  - IM
MH  - Administration, Topical
MH  - Aminolevulinic Acid/*administration & dosage/chemistry/pharmacokinetics
MH  - Animals
MH  - Carcinoma, Basal Cell/drug therapy
MH  - Disease Models, Animal
MH  - Esters
MH  - Mice
MH  - Microscopy, Fluorescence
MH  - Photochemotherapy
MH  - Photosensitizing Agents/*administration & dosage/chemistry/pharmacokinetics
MH  - Protoporphyrins/metabolism
MH  - Skin Neoplasms/drug therapy
MH  - Swine
MH  - Tissue Adhesives/pharmacology
EDAT- 2010/07/17 06:00
MHDA- 2010/12/21 06:00
CRDT- 2010/07/17 06:00
PHST- 2009/12/23 00:00 [received]
PHST- 2010/06/06 00:00 [revised]
PHST- 2010/06/21 00:00 [accepted]
PHST- 2010/07/17 06:00 [entrez]
PHST- 2010/07/17 06:00 [pubmed]
PHST- 2010/12/21 06:00 [medline]
AID - S1011-1344(10)00144-2 [pii]
AID - 10.1016/j.jphotobiol.2010.06.012 [doi]
PST - ppublish
SO  - J Photochem Photobiol B. 2010 Oct 5;101(1):59-69. doi: 
      10.1016/j.jphotobiol.2010.06.012. Epub 2010 Jun 30.