Linked Life Data

8818988

Source:http://linkedlifedata.com/resource/pubmed/id/8818988

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
7
pubmed:dateCreated
1997-2-6
pubmed:abstractText
The effects of (i) a series of chemical enhancers and (ii) the combination of these enhancers and therapeutic ultrasound (1 MHz, 1.4 W/cm2, continuous) on transdermal drug transport are investigated. A series of chemical enhancer formulations, including (i) polyethylene glycol 200 dilaurate (PEG), (ii) isopropyl myristate (IM), (iii) glycerol trioleate (GT), (iv) ethanol/pH 7.4 phosphate buffered saline in a 1:1 ratio (50% EtOH), (v) 50% EtOH saturated with linoleic acid (LA/EtOH), and (vi) phosphate buffered saline (PBS), as a control, are evaluated using corticosterone as a model drug. LA/EtOH is the most effective of these enhancers, increasing the corticosterone flux by 900-fold compared to that from PBS. Therapeutic ultrasound (1 MHz, 1.4 W/cm2, continuous) increases the corticosterone permeability from all of the enhancers examined by up to 14-fold (LA/EtOH) and increases the corticosterone flux from the saturated solutions by up to 13,000-fold (LA/EtOH), relative to that from PBS. Similar enhancements are obtained with LA/EtOH with and without ultrasound for four other model drugs, dexamethasone, estradiol, lidocaine, and testosterone. The permeability enhancements for all of these drugs resulting from the addition of linoleic acid to 50% EtOH increase with increasing drug molecular weight. Likewise, the permeability enhancement attained by ultrasound and LA/EtOH relative to passive EtOH exhibits a similar size dependence. A mechanistic explanation of this size dependence is provided. It is suggested that bilayer disordering agents, such as linoleic acid and ultrasound, transform the SC lipid bilayers into a fluid lipid bilayer phase or create a separate bulk oil phase. The difference in diffusivity of a given solute in SC bilayers and in either fluid bilayers or bulk oil is larger for larger solutes, thereby producing greater enhancements for larger solutes.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0022-3549
pubmed:author
pubmed:issnType
Print
pubmed:volume
85
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
670-9
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1996
pubmed:articleTitle
Synergistic effects of chemical enhancers and therapeutic ultrasound on transdermal drug delivery.
pubmed:affiliation
Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge 02139, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't