1,720,962 research outputs found
UV-A sunscreen incorporation in lipidic microparticles
No full textThe present study has involved the development of lipospheres loaded with BMDBM, prepared by the melt method. The obtained samples were evaluated for morphology, size, BMDBM loading level, physical state, in vitro release and photostability
Encapsulation of hydroxypropyl-beta-cyclodextrin/butyl methoxydibenzoylmethane complex in lipospheres
No full textThe incorporation of the sunscreen butyl methoxydibenzoylmethane complexed with beta-cyclodextrins into lipid microparticles allowed to enhance the sunscreen agent photostability and hence its photoprotective capacity
Encapsulation in lipospheres of the complex between butyl methoxydibenzoylmethane and hydroxypropyl-beta-cyclodextrin
No full textThe aim of this study was to investigate the incorporation into lipospheres of the complex between hydroxypropyl-beta-cyclodextrin (HP-beta-CD) and the sunscreen agent, butyl methoxydibenzoylmethane (BMDBM) and to examine the influence of this system on the sunscreen photostability. The formation of the inclusion complex was confirmed by thermal analysis and powder X-ray diffraction. Lipid microparticles loaded with free BMDBM or its complex with HP-beta-CD were prepared using tristearin as the lipid material and hydrogenated phosphatidylcholine as the emulsifier. The obtained lipospheres were characterized by scanning electron microscopy and differential scanning calorimetry. The microparticle size (15-40 mu m) was not affected by the presence of the complex. Release of BMDBM from the lipospheres was lower when it was incorporated as inclusion complex rather than as free molecule. Unencapsulated BMDBM, its complex with HP-beta-CD, the sunscreen-loaded lipospheres or the lipoparticles containing the BNDBM/HP-beta-CD complex, were introduced into a model cream (oil-in-water emulsion) and irradiated with a solar simulator. The photodegradation studies showed that all the examined systems achieved a significant reduction of the light-induced decomposition of the free sunscreen agent (the BMDBM loss decreased from 28.9 to 17.3-15.2%). However, photolysis experiments performed during 3 months storage of the formulations, demonstrated that the photoprotective properties of the HP-beta-CD complex and of BMDBM alone-loaded lipospheres decreased over time, whereas the microencapsulated HP-beta-CD/BMDBM complex retained its photostabilization efficacy. Therefore, incorporation in lipid microparticles of BMDBM in the cyclodextrin complex form is more effective in enhancing the sunscreen photostability than the complex alone or the liposphere-entrapped free BMDBM. (c) 2006 Elsevier B.V. All rights reserved
Influence of liposphere preparation on butyl-methoxydibenzoylmethane photostability
No full textThe incorporation of butyl-methoxydibenzoylmethane (BMDBM), one of the most efficient and frequently used UV-A blockers, into lipospheres was examined in order to decrease the light-induced sunscreen degradation. Lipospheres, obtained by the melt technique and using tristearin as the lipid material and hydrogenated phosphatidylcholine as the emulsifier, showed proper features in terms of size (1040 mu m), BMDBM loading level (21.63% +/- 0.90%, w/w) and physical state. Photolysis studies, involving irradiation of lipospheres with simulated sunlight before and after their introduction in emulsion formulations, demonstrated a relevant enhancement of the encapsulated sunscreen photostability in comparison with unencapsulated BMDBM
Study of effect of liposphere encapsulation on the photostability of the sunscreen agent, butyl methoxydibenzoylmethane
No full textThe aim of this study was to examined the use of lipid microparticles (lipospheres) as carrier for the sunsceen agent and the influence of the lipospheres on the photostability of BMDBM
Incorporation of sunscreen agents in textile grafted with beta-ciclodestrin
No full textThe present study describes a different approach for the coating of sunscreen agents on cloting . The procedure involves the covalent binding of cyclodextrin onto the cloth fibres foloowed by inclusion compelxation of the UV filters in the cyclodextrin cavities grafted on teh textile surfac
Use of cyclodextrins to decrease the penetration of the sunscreen, benzophenone-3 through human skin
No full textThe objective of the study was to examine the influence of cyclodextrins on teh skin penetration of the sunscreen benzophenone-3.The sunscren agent fre or complexed with cyclodextrin was applied to th epidermal surface inthe donor compartment of Franz diffusion cells. The results obtained demonstrated that complexation with hydroxypropyl-beta-cyclodextrin produced a more localized distribution of teh sunscren agent on the skin surface thereby enhancing its photoprotective powe
Lipospheres as carrier for sunscreen agents
No full textLipospheres as carrier for sunscreen agents were prepared by melt technique and evaluated for skin penetration
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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