Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0152030 (skin irritation)
 2,146 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Comparisons were made of branched vs unbranched saturated fatty acids and cis vs trans unsaturated fatty acids as skin penetration enhancers and primary skin irritants. Skin penetration studies used naloxone base as the diffusant, propylene glycol as the vehicle, and human skin. Maximum naloxone flux was with C9-12-branched and unbranched fatty acids. For C5-14 fatty acids, branched and unbranched isomers had similar effects. One branched C18 fatty acid isomer (C16-branched isostearic acid) was more effective in enhancing skin penetration than a differently branched (C2-branched isostearic acid) or unbranched C18 isomer (stearic acid). There was no significant difference between cis and trans unsaturated C16-18 fatty acid isomers in their effects on naloxone flux, and all unsaturated fatty acids were more effective enhancers than the corresponding saturated isomers. Several of these fatty acid/propylene glycol vehicles were evaluated in a rabbit primary skin irritation test. Irritation indices were poorly correlated with the effectiveness of the vehicles in enhancing naloxone flux. It was possible to enhance naloxone skin penetration greatly with a vehicle with only minimal skin irritation potential.
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PMID:Structure/effect studies of fatty acid isomers as skin penetration enhancers and skin irritants. 272 82

Polyethylene Glycol (PEG)-6, -8, and -20 Sorbitan Beeswax are ethoxylated derivatives of Beeswax that function as surfactants in cosmetic formulations. Only PEG-20 Sorbitan Beeswax is currently reported to be used, at concentrations up to 11%. Few data on the PEGs Sorbitan Beeswax ingredients were available. This safety assessment relied upon the available data from previous safety assessments of Beeswax, Synthetic Beeswax, Sorbitan Esters, PEGs, and PEG Sorbitan fatty acid esters, also known as Polysorbates. The ester linkage of PEG Sorbitan fatty acid esters was hydrolyzed after oral administration, and the PEG Sorbitan moiety was poorly absorbed from the gastrointestinal tract. Sorbitan Stearate was hydrolyzed to stearic acid and anhydrides of sorbitol in the rat. PEGs are readily absorbed through damaged skin and are associated with contact dermatitis and systemic toxicity in burn patients. PEGs were not sensitizing to normal skin. PEGs did not cause reproductive toxicity, nor were tested PEGs mutagenic or carcinogenic. Sorbitol was not a reproductive or developmental toxin in multigenerational studies in rats. Neither Beeswax nor Synthetic Beeswax produced significant acute animal toxicity, ocular irritation, skin irritation, or skin sensitization. Polysorbates produced no acute or long-term effects, were generally not irritating or sensitizing, and were noncarcinogenic, although studies did demonstrate enhancement of the activity of chemical carcinogens. Sorbitan fatty acid esters were relatively nontoxic via ingestion, generally were not skin irritants or sensitizers, and were not mutagenic or carcinogenic. Sorbitan Laurate was a cocarcinogen in a mouse skin-painting study. PEG-6 Sorbitan Beeswax delivered via a stomach tube was nontoxic in rats in acute studies. Undiluted PEG-6 Sorbitan Beeswax was nonirritating to the eyes of rabbits and was non-irritating to intact and abraded skin of rabbits. PEG-20 Sorbitan Beeswax was only minimally irritating to rabbit eyes at concentrations as high as 30%, and was not a significant skin irritant in rabbits exposed to a product with PEG-20 Sorbitan Beeswax at 2%. In clinical tests, PEG-6 and -20 Sorbitan Beeswax at concentrations up to 3% were only minimally irritating and were nonsensitizers. Careful consideration was made of the data on the cocarcinogenesis, but the high exposure levels, high frequency of exposure, and absence of a dose-response led to the conclusion that there was not a cocarcinogenesis risk with the use of these ingredients in cosmetic formulations. Accordingly, these ingredients were considered safe for use in cosmetic formulations under the present practices of use.
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PMID:Final report on the safety assessment of PEG-6, -8, and -20 sorbitan beeswax. 1180 50

Cosmetic skin care products currently in the market demonstrate an increasing trend toward antiaging products. Selection of the right formulation approach is the key to successful consumer acceptance. Nanostructured lipid carriers (NLCs) for dermal application can render added benefits to the formulation. Tretinoin a derivative of vitamin A, is a retinoid with anti-aging and anti-acne potential. The present study was aimed at formulating NLCs of tretinoin for reducing the skin irritation potential, increasing the drug loading capacity and prolonging the duration of action. The NLCs were optimized using the response surface methodology based on the particle size. Preliminary study, suggested the use of stearic acid, oleic acid, Tween 80 and Span 60 as solid lipid, liquid lipid and surfactants respectively formed a stable dispersion. NLCs of tretinoin were prepared by hot melt microemulsion and hot melt probe sonication methods. The properties of the optimized NLCs such as morphology, size, Zeta potential, stability and in vitro drug release were investigated. Tretinoin loaded NLCs in carbopol gel showed a sustained release pattern with isopropyl alcohol as the receptor fluid compared to the marketed gel using Franz diffusion cells. Eight prepared gel formulations tested were found to follow the Higuchi model of drug release. Stability studies indicated that the formulations stored at refrigeration and room temperature showed no noticeable differences in the drug content and release profiles in vitro, after a period of 4 weeks. In vivo skin irritation test on male Wister rats indicated no irritation or erythema after application of the NLCs loaded gel repeated for a period of 7 days compared to the application of marketed tretinoin gel which showed irritation and slight erythema within 3 days. The results showed that the irritation potential of tretinoin was reduced, the drug loading was increased and the drug release was prolonged by the incorporation into the NLCs.
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PMID:Nanostructured lipid carriers for the topical delivery of tretinoin. 2751 27