Linked Life Data

12551704

Source:http://linkedlifedata.com/resource/pubmed/id/12551704

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2003-1-28
pubmed:abstractText
Investigations to determine pH profiles across human stratum corneum (SC), in vivo as well as in vitro, were carried out using the tape stripping technique and a flat surface pH electrode. This method was extended to the deeper skin layers (=viable epidermis+dermis; DSL) in vitro. Statistically significant changes in the pH values were detected in the SC between in vivo and in vitro investigations and also between male and female skin in vivo. For the DSL, no gender-dependent differences in pH were observed. While the results achieved for the SC are in accordance with data already published in the literature, the values for the DSL were surprising: An alkaline pH, with a steep increase of about two pH units in the first 100 microm of the DSL and a plateau of this level was thereafter detected. Research was also done to examine the influence of different in vitro test systems on the results of pH measurements across the skin. A permeation model (Franz diffusion cell; FD-C) and a penetration model (Saarbruecken penetration model; SB-M) were compared. Experiments were carried out concerning the incubation time as well as the pH of the acceptor solution in the FD-C. Independent of the test system used, no change in the pH profiles could be observed for the SC, but a strong effect of the acceptor medium and its pH on the pH profiles across the DSL could be demonstrated using the FD-C, which showed itself partly after 30 min in statistically significant differences between incubated and formerly frozen skin. The results after the use of buffer solutions with different pH values, the pH across the DSL seemed to come into line with the one of the buffer solution, which was investigated for acidic as well as alkaline pH values. The results obtained with the flat surface pH electrode were confirmed using two different dyes: the pH-dependent fluorescent dye carboxy-SNARF-1 and the pH indicator bromthymolblue.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0939-6411
pubmed:author
pubmed:issnType
Print
pubmed:volume
55
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
57-65
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:12551704-Adult, pubmed-meshheading:12551704-Benzopyrans, pubmed-meshheading:12551704-Bromthymol Blue, pubmed-meshheading:12551704-Buffers, pubmed-meshheading:12551704-Dermis, pubmed-meshheading:12551704-Drug Delivery Systems, pubmed-meshheading:12551704-Epidermis, pubmed-meshheading:12551704-Female, pubmed-meshheading:12551704-Fluorescent Dyes, pubmed-meshheading:12551704-Humans, pubmed-meshheading:12551704-Hydrogen-Ion Concentration, pubmed-meshheading:12551704-Indicators and Reagents, pubmed-meshheading:12551704-Male, pubmed-meshheading:12551704-Middle Aged, pubmed-meshheading:12551704-Models, Biological, pubmed-meshheading:12551704-Naphthols, pubmed-meshheading:12551704-Permeability, pubmed-meshheading:12551704-Rhodamines, pubmed-meshheading:12551704-Sex Factors, pubmed-meshheading:12551704-Skin Absorption
pubmed:year
2003
pubmed:articleTitle
pH profiles in human skin: influence of two in vitro test systems for drug delivery testing.
pubmed:affiliation
Department of Biopharmaceutics and Pharmaceutical Technology, Saarland University, Saarbruecken, Germany.
pubmed:publicationType
Journal Article, Comparative Study, In Vitro, Research Support, Non-U.S. Gov't