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Query: UMLS:C0849640 (skin damage)
 1,516 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Fractal analysis of the cross-sectional morphology of rat skin was conducted to evaluate pathologic changes evoked by percutaneous absorption enhancers. Male hairless rats (WBN/Ht-ILA), 8 weeks old, weighing 160 to 180 g were used. Under anesthetization, glass cells (10-mm inner diameter) were attached to the rats' abdomens, and test solutions containing various mixtures of the percutaneous absorption enhancers, sodium lauryl sulfate, isopropanol, 2-methyl-1-butanol, and sodium myristate were applied. Six hours after application, the solutions were removed and the abdominal skin was excised. Skin cross sections were analyzed with a charge-coupled device (CCD) camera. Image data taken by the CCD camera were fed into a desktop digital computer; then the fractal dimension of each skin cross section was determined on the basis of the box-counting algorithm. A pathologic study was also performed on the skin treated with the test solution. All sections of skin were examined with an optical photo microscope. Pathologic findings were classified into five levels. The total irritation score (TIS) was defined as the summation of damage levels in all regions. Only with the administration of hydrogel containing 2-methyl-1-butanol or sodium lauryl sulfate were positive values of TIS observed. However, the TIS values were independent of the concentration of these components. The most severe skin damage was evoked by application of sodium lauryl sulfate. Noticeable skin damage was also seen with 2-methyl-1-butanol. No irritation to the skin resulted from treatment with isopropanol or sodium myristate. When test solution containing sodium lauryl sulfate was applied to the skin, a remarkable increment in fractal dimensions was noted. This may suggest that the structure of the skin was greatly compromised as a result of sodium lauryl sulfate application. Although no change in fractal dimension was observed as a result of application of the test solution containing only 25% isopropanol, the fractal dimension of skin cross section gradually increased with increasing concentrations of isopropanol, 2-methyl-1-butanol or sodium myristate in the test solutions. The increment of fractal dimension was around 0.4. Thus, the skin structure was also altered by the application of high concentrations of these compounds. Although the relevance to humans is not known, fractal analysis of skin structure is thought to be useful as a novel method for detecting skin damage that is brought about by the application of percutaneous absorption enhancers.
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PMID:Evaluation of skin damage caused by percutaneous absorption enhancers using fractal analysis. 1073 17

Glibenclamide(GLI) is widely used as an oral hypoglycemic drug in the treatment of non-insulin dependent diabetes mellitus (NIDDM). We investigated The enhancing effect of switching iontophoresis on the transdermal absorption and reduction of skin irritation to develop a transdermal dosage form of GLI. The 0.1% of Gli suspensions in 0.2 M tris-HCl buffer of pH 7.4, 8.0 and 8.5 were prepared as donor solutions. We examined drug permeation through the excised rat abdominal skin, drug absorption in rats and reduction of skin irritation after application of switching iontophoresis for 1 h using DC 10 V. The solubility of GLI in 0.2 M tris-HCl buffer increased with a rise in pH. In the permeation study, GLI was permeated continuously and the cumulative amount of permeated GLI increased using an alkaline donor solution. In the drug absorption study, the application group of pH 8.5 gave higher plasma concentration levels than those of pH 7.4 and 8.0 groups. The skin irritation evoked by the application of iontophoresis was pathologically studied. A total irritation score (TIS) was estimated as a judging standard for the skin damage. The TIS value increased dependently with a rise in pH. However, it was considered that the skin irritations were not serious and small matters. The results demonstrate the possibility of iontophoretic transdermal administration of GLI and the effect of drug solubility in the donor solution on the absorption of GLI.
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PMID:[Enhancing effect of switching iontophoresis on transdermal absorption of glibenclamide]. 1121 30