A novel nanoemulsification method of stirring at the Θ-point with the tocopherol-based block co-polymer nonionic emulsifier PPG-20 Tocophereth-50 / Young-Dae Kim in IFSCC MAGAZINE, Vol. 7, N° 4 (10-11-12/2004)

[article]  inIFSCC MAGAZINE > Vol. 7, N° 4 (10-11-12/2004) . - p. 319-325 Titre : A novel nanoemulsification method of stirring at the Θ-point with the tocopherol-based block co-polymer nonionic emulsifier PPG-20 Tocophereth-50 Type de document : texte imprimé Auteurs : Young-Dae Kim, Auteur ; Jung-Soo Kim, Auteur ; Iwhan Cho, Auteur ; Ki Woo Kim, Auteur Année de publication : 2004 Article en page(s) : p. 319-325 Note générale : Bibliogr. Langues : Anglais (eng) Tags : Nanoemulsion  'weight  fraction  of  dispersed  phase  (?)'  'block  co-polymer  amphiphile'  'mean  particle  size'  stability  'cryo-scanning  electron  microscopy'  '?-point' Index. décimale : 668.5 Parfums et cosmétiques Résumé : Nanoemulsions have recently become increasingly important as potential vehicles for the controlled delivery of cosmetics and for the optimized dispersion of active ingredients in particular skin layers. The preparation of conventional nanoemulsions requires mainly high-pressure homogenization, which is unproductive and requires high energy due to its lower efficiency, limiting their practical applications. In order to solve these problems novel nanoemulsions were studied using a model system of pseudo-ternary water/emulsifier/paraffin oil. Nanoemulsions were prepared by stirring a mixture of the tocopherol-containing block co-polymer emulsifier PPG-20 Tocophereth-50, paraffin oil, and distilled water at the Θ-point using weight fractions of the dispersed phase (φ) of 0.31 to 0.82 and an emulsifier content of 1.0 to 9 wt.%. The emulsifying property of PPG-20 Tocophereth-50 in nanoemulsions was compared with that of the conventional emulsifiers Tocophereth-43, a mixture of polysorbate 60 and sesquioleate (3/1), and phospholipids. Also the emulsifying property of PPG-20 Tocophereth-50 in the more hydrophilic oils caprylic/capric triglyceride and octyldodecanol was compared with that in paraffin oil. The stability and morphology of the resulting nanoemulsions were studied by visual inspection, optical microscopy, particle size analysis, and cryo-scanning electron microscopy. In the nanoemulsion systems containing caprylic/capric triglyceride and octyldodecanol, respectively, as an oil phase PPG-20 Tocophereth-50 showed emulsification properties similar to those in paraffin oil. The conventional emulsifiers Tocophereth-43, a mixture of polysorbate 60 and sesquioleate (3/1), and phospholipids did not give nanoemulsions with high-speed stirring. The block co-polymer nonionic emulsifier PPG-20 Tocophereth-50 was found to produce stable nanoemulsions of mean droplet diameters ranging from 204 to 499 nm. The emulsification method of high-speed stirring at the Θ-point using PPG-20 Tocophereth-50 was found to be very effective for the preparation of stable nanoemulsions useful for applications in skincare cosmetics, cosmeceuticals, and drugs. Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=10485 [article]

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Polyoxypropylene-polyoxyethylene tocopheryl ethers: a series of novel amphiphiles from tocopherol for functional cosmetics / Young-Dae Kim in IFSCC MAGAZINE, Vol. 4, N° 4 (10-11-12/2001)

[article]  inIFSCC MAGAZINE > Vol. 4, N° 4 (10-11-12/2001) . - p. 269-276 Titre : Polyoxypropylene-polyoxyethylene tocopheryl ethers: a series of novel amphiphiles from tocopherol for functional cosmetics Type de document : texte imprimé Auteurs : Young-Dae Kim, Auteur ; Bong Rae Cho, Auteur ; Kyoung-Chan Park, Auteur Année de publication : 2001 Article en page(s) : p. 269-276 Note générale : Bibliogr. Langues : Anglais (eng) Tags : 'Polyoxypropylene-polyoxyethylene  tocopheryl  ether'  Amphiphiles  'Functional  cosmetics'  Anti-oxidant  Melanin  Erythema  Emulsion  Vesicle  'Liquid  crystal' Index. décimale : 668.5 Parfums et cosmétiques Résumé : A series of novel non-ionic compounds, polyoxypropylene-polyoxyethylene tocopheryl ethers [POP(n)-POE(m)TEs], was synthesized by a two-step alkoxylation reaction with ethylene oxide and propylene oxide of tocopherol. The resulting molecules have been demonstrated to have potential use in functional cosmetics. Both 1H-NMR and FT-IR as well as elemental analysis methods were used to characterize the structure. By virtue of an in-vitro peroxide value study using evening primrose oil, some POP(n)-POE(m)TEs demonstrated better anti-oxidative activity than DL- α-tocopherol. In-vivo human skin protection tests showed that pre- and post-application of some POP(n)-POE(m)TEs significantly decreased the melanin pigment formation and erythema development on UVB-irradiated human skin thus indicating that some POP(n)-POE(m)TEs have significant potential for in-vivo anti-oxidative activity and/or anti-inflammation effects. Systematic safety studies demonstrate that POP(n)-POE(m)TEs to be safe for use in personal care applications. The test results of technological and practical applications for functional cosmetics showed that some POP(n)-POE(m)TEs make stable emulsion as well as liquid crystal bilayer vesicles. Some POP-n)-POE(m)TEs were shown to make very fine emulsions with long-term stability at 40°C even in very low viscosity emulsions. The formation of liquid crystals in low viscosity emulsions was confirmed by polarized light microscopy. Transmission electron microscopy (TEM) for uranyl acetate stained solutions of POP(n)-POE(m)TEs confirmed the property of vesicle formation. These results indicate that POP(n)-POE(m)TEs offer an alternative approach in improving product property versus conventional cosmetic surfactants in terms of safety, stability, and chemical and biological effect for functional cosmetics. Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=10688 [article]

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