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Endocrine disruptors in consumer goods
Pařízková, Alžběta ; Šuta, Miroslav (advisor) ; Cajthaml, Tomáš (referee)
The Thesis focuses on the group of specific organic compounds with a potential risk of their endocrine disruptive effect, and appearing as UV filters in various cosmetic products. An extended list of such products was created on the basis of search in drugstores, pharmacies and perfume shops. The products were further grouped as cosmetics for adults, children, and those declared as bio products. The source data collection counted 156 individual products, with origin in 40 drugstores, 20 pharmacies, and 10 perfume shops. The data collection sites were distributed in big cities, their suburb parts, shopping parks, and small towns on many places in the Czech Republic. The products were mostly sun protection creams, oils and emulsions, body creams and emulsions, lips balsams, and hair cosmetics. In these items an occurrence of 7 organic compounds (suspected endocrine disruptors) from the SIN List, used as parts of UV filters, was followed. The compounds of interest were: ethylhexyl methoxycinnamate; benzophenone-1, benzophenone-2, benzophenone-3; 4,4-dihydroxyphenone; 4-methylbenzylidene camphor; 3-benzylidene camphor. Alternative names, product brand names, chemical structures, CAS numbers etc. were also collected from various sources. Of this group only ethylhexyl methoxycinnamate and benzophenone-3...
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Preparation and application of nanoparticles and nanofibres with natural UV filters
Plachá, Monika ; Skoumalová, Petra (referee) ; Márová, Ivana (advisor)
The presented diploma thesis is focused on preparation of nanoparticles and nanofibres with natural UV filters. Liposomes with encapsulated aqueous, ethanol and lipid extracts were prepared. Nanofibers from PHB containing lipid extract were prepared too. As a part of this work, an overview of natural sources with potential effects as UV filters were introduced. Moreover, nanoparticles and nanofibers and methods of their characterization were described. Size, polydisperse index and colloid stability of prepared nanoparticles were characterized via DLS. In experimental part aqueous, ethanol and lipid extracts were prepared from roasted coffee, green coffee and cascara. These extracts were spectrophotometrically characterized for the content of polyphenols, flavonoids, antioxidant activity, tannins and their SPF. Liposomes and liposomes containing PHB with these extracts were prepared and the encapsulation effectivity, short–term and long–term stability as well as SPF of nanoparticles were determined. Nanofibers from PHB containing lipid extracts were prepared via electrospinning and forcespinning methods. Prepared nanofibers were examined via FTIR–ATR. Antioxidant activity, short–term and long–term stability were determined spectrophotometrically. From selected nanoparticles, emulsions and gels were prepared and their SPF was also determined. Three types of emulsions with the best SPF were selected and tested on volunteers. Sedimentation stability of emulsions was tested by analytical centrifuge. Finally, cytotoxicity of selected nanoparticles and nanofibers was tested via MTT assay using human keratinocytes.
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Preparation and characterization of cosmetic emulsion with addition of active compounds
Zinkovska, Natalia ; Smilková, Marcela (referee) ; Smilek, Jiří (advisor)
In the theoretical part, this bachelor’s thesis focuses on the overview of the basic characteristics and properties of the emulsion. Great attention is paid to choosing the type of emulsifier and the calculation hydrophilic-lipophilic balance. The mechanisms andcauses of instability of emulsions and their possible prevention and methods of stabilization are analyzed. The present state of the problem aimed to the analysis of existing methods for determination of emulsion stability and their use in practice is also part of this thesis. The experimental part of the work is primarily focused on the preparation of O/W cosmetic emulsions with additive of active substances such as UV absorbers. To characterize the prepared samples, pH values were measured and viscosities determined. The stability of the emulsion was carried out using an analytical centrifuge, and these results were further correlated with the standard gravitational stability tests (change of storage temperature of the formulation) according to the SÚKL methodical guidelines (REG-49, REG 51), which are the Czech version of the 75/318 /: Stability tests on active ingredients and finished products. Methods of preparation and composition of individual samples are described, which is further correlated with the stated characteristics of prepared creams.
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Preparation and characterization of biomaterials with natural UV filtres
Pavelková, Renata ; Čarnecká, Martina (referee) ; Márová, Ivana (advisor)
This presented diploma thesis is focuses on preparation and characterization of biomaterials with natural UV filters. The theoretical part is aimed at effects of sunlight on the skin and how to avoid these effects by using cosmetic products. The materials and methods for extraction of lipid part of the selected vegetable and microorganism species and methods for preparation and characterization of nanoparticles and emulsions were characterized. The practical part deals with extraction of lipid part of selected vegetable and microorganism species. The liposome particles with encapsulated active compounds were prepared. The particle size, polydispersity index, colloidal stability, encapsulation efficiency, SPF, antioxidant capacity, phospholipid content and cytotoxic effect on human keratinocytes were observed. These particles were used for preparation of the resulting emulsions. Their protection level on UV light were set and stability were tested by using analytical centrifugation.
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Application of nanoparticles and nanofibers with active compound in cosmetics
Pavelková, Renata ; Obruča, Stanislav (referee) ; Márová, Ivana (advisor)
Presented bachelor thesis is focused on application of nanoparticles and nanofibers with active compound in cosmetics. The theoretical part is aimed at effect of UV radiation on the skin and compounds that are used in photo protection of the skin. The materials and methods used in nanoparticle and nanofiber preparing were characterized. The experimental part deals with preparing of liposomes and marinosomes with active compound. Particles size, stability measured using zeta potential and stability in model environment were observed. Finally, pilot experiments of optimization of nanofibers preparation using electrospinning were carried out.
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Optical properties of protective emulsions
Valasová, Denisa ; Veselý, Michal (referee) ; Zmeškal, Oldřich (advisor)
This bachelor´s thesis is aimed to the study of optical properties of protective commercially available emulsions. Chosen emulsions should be responsible for sun protection. They also may be used in cosmetic industry. In the beginning of the thesis, there are defined theoretical features of emulsions and their interaction with UV radiation. Methods which are used to describe optical properties could be found in this section too. The optical properties were measured in thin layer films, in order to simulate emulsions applied on the human skin. UV-VIS spectrophotometry was mainly used to study the optical properties. The obtained results could serve, purely hypothetically, like sun protective tests of chosen emulsions.
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