Linked Life Data

8742943

Source:http://linkedlifedata.com/resource/pubmed/id/8742943

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
1996-10-2
pubmed:abstractText
Previously, the effects of a series of 1-alkyl-2-pyrrolidones (APs; C2-C8) on the lipoidal pathway of hairless mouse skin (HMS) were studied with a parallel pathway skin model. At their isoenhancement concentrations, these 1-alkyl-2-pyrrolidones induce the same transport enhancement (isoenhancement factor, EHMS) on the lipoidal pathway of the stratum comeum for the probe permeants studied. In the present study, the fluidizing effects of APs upon the stratum comeum lipid liposome (SCLL) bilayer were investigated under these isoenhancement conditions using steady state anisotropy and fluorescence lifetime studies with fluorescent probes 2-, 6-, and 9-(9-anthroyloxy)stearic acids, 16-(9-anthroyloxy)palmitic acid, and 1,6-diphenyl-1,3,5-hexatriene to examine a possible correlation between the fluidizing properties of APs and their enhancement effects on transdermal drug transport. Time-resolved fluorescence decay studies were also conducted to further investigate the fluidizing properties of APs and add support to the steady-state fluorescence results. Under an isoenhancement condition of EHMS = 10, these APs fluidized the alkyl chains of the lipids at intermediate depths (C6-C9) in the SCLL bilayer (a 40-50% decrease in the rotational correlation times) but did not significantly change the fluidity in the deep hydrophobic region of the bilayer. Three rotational correlation times were deduced from the global simultaneous analysis in time-resolved fluorescence decay measurements. The slowest of these (greater than 1000 ns) was attributed to the global motion of SCLLs and is probably related to the static component of steady-state anisotropy. The other two rotational correlation times (on the order of nanoseconds) were in the range expected for the local motion of the fluorophores and may correspond to their vibrational and rotational motions. When the concentrations of APs were increased (increasing the EHMS value), the static component (alpha) decreased. This suggests that APs might induce a general fluidizing effect upon the lipid bilayer (i.e., a decrease in the order of the lipid bilayer). The decrease in the longer rotational correlation time (on the order of nanoseconds) with increasing EHMS value, on the other hand, indicates a possible increase in the "cavity volume" for the hindered motions of the fluorophores (i.e., an increase in the free volume at intermediate depths in the bilayer).
pubmed:grant
pubmed:commentsCorrections
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0022-3549
pubmed:author
pubmed:issnType
Print
pubmed:volume
85
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
511-7
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
1996
pubmed:articleTitle
Fluorescent probe studies of the interactions of 1-alkyl-2-pyrrolidones with stratum corneum lipid liposomes.
pubmed:affiliation
Department of Pharmaceutics and Pharmaceutical Chemistry, University of Utah, Salt Lake City 84112, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't