| 1. |
- Akerstrom, Ulf, et al.
(författare)
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Comparison of Moisturizing Creams for the Prevention of Atopic Dermatitis Relapse: A Randomized Double-blind Controlled Multicentre Clinical Trial
- 2015
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Ingår i: Acta Dermato-Venereologica. - : Medical Journals Sweden AB. - 1651-2057 .- 0001-5555. ; 95:5, s. 587-592
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Tidskriftsartikel (refereegranskat)abstract
- Atopic dermatitis (AD) affects adults and children and has a negative impact on quality of life. The present multicentre randomized double-blind controlled trial showed a barrier-improving cream (5% urea) to be superior to a reference cream in preventing eczema relapse in patients with AD (hazard ratio 0.634, p = 0.011). The risk of eczema relapse was reduced by 37% (95% confidence interval (95% CI) 10-55%). Median time to relapse in the test cream group and in the reference cream group was 22 days and 15 days, respectively (p = 0.013). At 6 months 26% of the patients in the test cream group were still eczema free, compared with 10% in the reference cream group. Thus, the barrier-improving cream significantly prolonged the eczema-free time compared with the reference cream and decreased the risk of eczema relapse. The test cream was well tolerated in patients with AD.
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| 2. |
- Albèr, Cathrine, et al.
(författare)
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Effects of water activity and low molecular weight humectants on skin permeability and hydration dynamics : a double-blind, randomized and controlled study
- 2014
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Ingår i: International Journal of Cosmetic Science. - : John Wiley & Sons. - 0142-5463 .- 1468-2494. ; 36:5, s. 412-418
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: The mammalian skin is a barrier that effectively separates the water-rich interior of the body from the normally dryer exterior. Changes in the external conditions, for example ambient humidity, have been shown to affect the skin barrier properties. The prime objective of this study was to evaluate the effect of water activity of a topical formulation on skin hydration and permeability. A second objective was to gain more understanding on how two commonly used humectants, urea and glycerol, affect skin barrier function in vivo. METHODS: Simple aqueous formulations were applied under occlusion to the volar forearm of healthy volunteers. Following 4-h exposure, skin water loss (by transepidermal water loss measurements), skin hydration (by Corneometry) and skin permeability (by time to vasodilation due to benzyl nicotinate exposure) were monitored. RESULTS: The results demonstrate that a relatively small change in the water activity of a topical formulation is sufficient to induce considerable effects on stratum corneum hydration and permeability to exogenous substances. Exposing the skin to high water activity leads to increased skin hydration and also increased permeability. Furthermore, urea and glycerol promote skin hydration and permeability even at reduced water activity of the applied formulation. CONCLUSION: These results highlight the importance of considering the water activity in topically applied formulations and the potential benefit of using humectants. The results may impact formulation optimization in how to facilitate skin hydration and to modify skin permeability by temporarily open and close the skin barrier.
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| 3. |
- Ali, Abdullah, 1985-
(författare)
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Topical formulations, design and drug delivery : "A dive into water"
- 2021
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Water is a vital component regulating the properties of topical formulations and their interaction with biological barriers, such as skin and mucosa. Changing the watercontent within the frame of the pharmaceutical triangle will have a huge impact on which type of formulation, such as a cream, ointment, gel, or lotion, is formed, as well as the physical properties of the formulation. The composition of a formulation, and the subsequent reformulation after application, will govern the features of the residual film. This will in turn affect the barrier properties of the underlying tissue and consequently the penetration of various substances across skin or mucosa.The primary aim of this thesis has been to provide further understanding on differences between traditional surfactant-based formulations and particle-stabilized, Pickering, formulations and how specific excipients, like alcohols, emollients, and thickeners can affect their physical and/or sensorial properties. The secondary aim has been to gain more knowledge on the role of water in topical formulations and how it affects the properties of the underlaying tissue on application.By combining a portfolio of physicochemical techniques combined with sensory science, we have been able to identify differences between Pickering and surfactantstabilized formulations. Starch-based Pickering emulsions were perceived as less greasy and sticky than traditional creams, even at high oil content. Moreover, we were able develop a novel type of alcohol-based Pickering emulsion with combined moisturizing and antiseptic properties. We have also been able to link sensory attributes, evaluated by human volunteers, with physicochemical characterizations. Furthermore, the in vitro ForceBoard™ method was developed further and we evaluated its potential to be used as an ex vivo method using excised skin. In addition, we have shown that that the water gradient over a biological barrier has a general relevance with respect to drug absorption and should be considered not only in dermaldrug delivery but also for buccal and nasal drug delivery.
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| 4. |
- Buraczewska, Izabela, et al.
(författare)
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Changes in skin barrier function following long-term treatment with moisturizers, a randomized controlled trial
- 2007
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Ingår i: British Journal of Dermatology. - : Oxford University Press (OUP). - 0007-0963 .- 1365-2133. ; 156:3, s. 492-498
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Moisturizers are commonly used by patients with dry skin conditions as well as people with healthy skin. Previous studies on short-term treatment have shown that moisturizers can weaken or strengthen skin barrier function and also influence skin barrier recovery. However, knowledge of the effects on skin barrier function of long-term treatment with moisturizers is still scarce. OBJECTIVES: To investigate the impact of long-term treatment with moisturizers on the barrier function of normal skin, as measured by transepidermal water loss (TEWL) and susceptibility to an irritant, and to relate those effects to the composition of the designed experimental moisturizers. METHODS: Volunteers (n = 78) were randomized into five groups. Each group treated one volar forearm for 7 weeks with one of the following preparations: (i) one of three simplified creams, containing only a few ingredients in order to minimize the complexity of the system; (ii) a lipid-free gel; (iii) one ordinary cream, containing 5% urea, which has previously been shown to decrease TEWL. The lipids in the simplified creams were either hydrocarbons or vegetable triglyceride oil, and one of them also contained 5% urea. After 7 weeks, treated and control forearms were exposed for 24 h to sodium lauryl sulfate (SLS) using a patch test. TEWL, blood flow and skin capacitance of both SLS-exposed and undamaged skin were evaluated 24 h after removal of patches. Additionally, a 24-h irritancy patch test of all test preparations was performed on 11 volunteers in order to check their possible acute irritancy potential. RESULTS: Changes were found in the barrier function of normal skin after 7 weeks of treatment with the test preparations. The simplified creams and the lipid-free gel increased TEWL and skin response to SLS, while the ordinary cream had the opposite effect. One of the simplified creams also decreased skin capacitance. All test preparations were shown to be nonirritant, both by short-term irritancy patch test and by measurement of blood flow after long-term treatment. CONCLUSIONS: Moisturizers influence the skin barrier function of normal skin, as measured by TEWL and susceptibility to SLS. Moreover, the effect on skin barrier function is determined by the composition of the moisturizer. The ingredients which influence the skin barrier function need to be identified, and the mechanism clarified at the molecular level.
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| 5. |
- Buraczewska, Izabela, et al.
(författare)
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Long-term treatment with moisturizers affects the mRNA levels of genes involved in keratinocyte differentiation and desquamation
- 2009
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Ingår i: Archives of Dermatological Research. - : Springer Science and Business Media LLC. - 0340-3696 .- 1432-069X. ; 301:2, s. 175-181
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Tidskriftsartikel (refereegranskat)abstract
- In a recent study, we showed that long-term treatment with two different moisturizers affected TEWL in opposite directions. Therefore, we decided to examine the effect of these moisturizers on the cellular and molecular level. In a randomized controlled study on 20 volunteers, epidermal mRNA expression of genes essential for keratinocyte differentiation and desquamation after a 7-week treatment with two moisturizers was analyzed. Treatment with one test moisturizer increased gene expression of involucrin, transglutaminase 1, kallikrein 5, and kallikrein 7, while the other moisturizer affected only expression of cyclin-dependent kinase inhibitor 1A. Thus, moisturizers are able to modify the skin barrier function and change the mRNA expression of certain epidermal genes. Since the type of influence depends on the composition of the moisturizer, these should be tailored in accordance with the requirement of the barrier of each individual patient, which merits further investigations.
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| 6. |
- Buraczewska, Izabela, et al.
(författare)
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Moisturizers change the mRNA expression of enzymes synthesizing skin barrier lipids
- 2009
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Ingår i: Archives of Dermatological Research. - : Springer Science and Business Media LLC. - 0340-3696 .- 1432-069X. ; 301:8, s. 587-594
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Tidskriftsartikel (refereegranskat)abstract
- In a previous study, 7-week treatment of normal human skin with two test moisturizers, Complex cream and Hydrocarbon cream, was shown to affect mRNA expression of certain genes involved in keratinocyte differentiation. Moreover, the treatment altered transepidermal water loss (TEWL) in opposite directions. In the present study, the mRNA expression of genes important for formation of barrier lipids, i.e., cholesterol, free fatty acids and ceramides, was examined. Treatment with Hydrocarbon cream, which increased TEWL, also elevated the gene expression of GBA, SPTLC2, SMPD1, ALOX12B, ALOXE3, and HMGCS1. In addition, the expression of PPARG was decreased. On the other hand, Complex cream, which decreased TEWL, induced only the expression of PPARG, although not confirmed at the protein level. Furthermore, in the untreated skin, a correlation between the mRNA expression of PPARG and ACACB, and TEWL was found, suggesting that these genes are important for the skin barrier homeostasis. The observed changes further demonstrate that long-term treatment with certain moisturizers may induce dysfunctional skin barrier, and as a consequence several signaling pathways are altered.
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| 7. |
- Buraczewska, Izabela, 1976-
(författare)
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Skin barrier responses to moisturizers
- 2008
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Moisturizers are used in various types of dry skin disorders, but also by people with healthy skin. It is not unusual that use of moisturizers is continued for weeks, months, or even years. A number of moisturizers have been shown to improve the skin barrier function, while others to deteriorate it, but the reason for observed effects remains unknown. Further understanding of the mechanism by which long-term treatment with moisturizers influences the skin barrier would have clinical implications, as barrier-deteriorating creams may enhance penetration of allergens or irritants and predispose to dry skin and eczema, while barrier-improving ones could reduce many problems. The present research combined non-invasive techniques with analyses of skin biopsies, allowing studies of the epidermis at molecular and cellular level. Test moisturizers were examined on healthy human volunteers for their effect on the skin barrier, with regard to such factors as pH, lipid type, and presence of a humectant, as well as complexity of the product. After a 7-week treatment with the moisturizers, changes in transepidermal water loss, skin capacitance, and susceptibility to an irritant indicated a modified skin barrier function. Moreover, the mRNA expression of several genes involved in the assembly, differentiation and desquamation of the stratum corneum, as well as lipid metabolism, was altered in the skin treated with one of the moisturizers, while the other moisturizer induced fewer changes. In conclusion, long-term use of moisturizers may strengthen the barrier function of the skin, but also deteriorate it and induce skin dryness. Moisturizers have also a significant impact on the skin biochemistry, detectable at molecular level. Since the type of influence is determined by the composition of a moisturizer, more careful selection of ingredients could help to design moisturizers generating a desired clinical effect, and to avoid ingredients with a negative impact on the skin.
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| 8. |
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| 9. |
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| 10. |
- Loden, Marie, et al.
(författare)
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Changes in European legislation make it timely to introduce a transparent market surveillance system for cosmetics
- 2007
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Ingår i: Acta Dermato-Venereologica. - : Society for the Publication of Acta Dermato - Venereologica. - 0001-5555 .- 1651-2057. ; 87:6, s. 485-492
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Tidskriftsartikel (populärvet., debatt m.m.)abstract
- Marketing of cosmetics often makes strong claims linked to active ingredients. This is especially so for anti-ageing products, where the presentation and content of "active" ingredients may create new difficulties in their classification as cosmetics or medicinal products. A recent change in European legislation classifies a product as medicinal by virtue of its "function", in addition to the previous definition of "presentation" (i.e. marketing linked to diseases). Thus, formulations that also restore, correct or modify physiological functions by exerting a pharmacological, immunological or metabolic action should henceforth be covered by the Medicinal Products Directive. A cosmetic product must be suitable for its purpose and should not lead to adverse reactions that are disproportional in relation to its intended effect. However, the forthcoming ban on animal testing of cosmetic ingredients and the new European regulation, REACH (Registration, Evaluation and Authorisation of Chemicals), which aims to ensure a high level of chemical safety to protect human health and the environment, will probably have limited impact on the safety assessment of cosmetics. In order to enable consumers to make informed purchasing decisions, greater transparency in the process of assessing the performance of cosmetics is needed. Introduction of a more transparent system, enabling consumers and professionals to examine the scientific evidence for the claimed effect and the safety assessment of cosmetics, is therefore timely. Lack of transparency increases the risk of consumers wasting money on cosmetics that do not deliver the desired effects. This may jeopardize public trust in the cosmetic industry.
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