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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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Sun protection factors determination for cosmetic emulsions
Slechanová, Veronika ; Jugl, Adam (referee) ; Smilek, Jiří (advisor)
The bachelor thesis deals with the anatomy and physiology of the skin, ultraviolet rays, sunscreens and current methods used to measure the value of sun protection factor. One of the goals of the thesis is to get the overview of the UV filters currently widely used in cosmetic products and giving them the required protection against the sun. The obtained knowledge was subsequently used for the determination of the sun protection factors in selected sunscreens by in vitro methods. The measurement provided satisfying results comparable with the values given on the label of the tested products. However, it is still necessary to optimize the methodology even more in order to obtain data with lower deviations and especially with much higher reproducibility.
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Awareness of the public of dangerous substances in cosmetic
NĚMCOVÁ, Kateřina
The title of my diploma thesis is "Awareness of the public of dangerous substances in cosmetic". It is divided into two parts - theoretical and practical. In the theoretical part, I focused on the history, general composition of cosmetic products and dangerous substances it contains. Considering the current trends of society I focused especially on decorative cosmetics. Because I have a negative experience with sunscreens, I concentrated on that issue in the last chapter of the theoretical part. The practical part is focused on the public's knowledge of dangerous substances in cosmetic products. The anonymous questionnaire was educative, because I assumed that many respondents would not inspect components contained in their cosmetic products. I made brief descriptions of the dangerous substances so respondents could get the most important information on this issue.
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Sun protection factors determination for cosmetic emulsions
Slechanová, Veronika ; Jugl, Adam (referee) ; Smilek, Jiří (advisor)
The bachelor thesis deals with the anatomy and physiology of the skin, ultraviolet rays, sunscreens and current methods used to measure the value of sun protection factor. One of the goals of the thesis is to get the overview of the UV filters currently widely used in cosmetic products and giving them the required protection against the sun. The obtained knowledge was subsequently used for the determination of the sun protection factors in selected sunscreens by in vitro methods. The measurement provided satisfying results comparable with the values given on the label of the tested products. However, it is still necessary to optimize the methodology even more in order to obtain data with lower deviations and especially with much higher reproducibility.
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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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Active ingredients in sun cosmetics
Jochimová, Eva ; Vránová, Dana (referee) ; Zemanová, Jana (advisor)
Active substances in sun cosmetics mean quantity and properties of UV-filters that absorb rays in UVA or in UVB areas. In the United States of America there are they considered as pharmaceuticals, however in European Union are they taken behind cosmetics. Their usage is very important, because the sun radiation can be very dangerous. Hazard of negative influences increases largely by downgrade of atmosphere and above all by enlargement of ozone hole. UVB and UVA rays penetrate into the skin where they can be a cause of different disorders. They evocate simply as far as heavily curable photodermatosis, skin ageing and cutaneous carcinoma in worse case.
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