Ugotavljanje vsebnosti in stabilnosti vitamina A in njegovih derivatov v kozmetičnih izdelkih

Škufca, Petja (author), Roškar, Robert (mentor), Temova Rakuša, Žane (comentor)

Vitamin A je pogosta aktivna sestavina v kozmetičnih izdelkih za zrelo in aknasto kožo. V kozmetiki so najpogostejši predstavniki vitamina A: beta karoten, retinol, retinal in retinilni estri nasičenih in nenasičenih maščobnih kislin. Retinojska kislina je edina biološko aktivna predstavnica vitamina A, vendar je v kozmetiki prepovedana. Cilj diplomske naloge je bil vrednotenje najpogostejših oblik vitamina A in opredelitev njihove vsebnosti v kozmetičnih izdelkih s pomočjo tekočinske kromatografije visoke ločljivosti. V izbor smo vključili 16 kozmetičnih izdelkov z navedeno vsaj eno obliko vitamina A. Ker se soočamo s problemom premajhnega nadzora nad kozmetičnimi izdelki, smo naredili primerjavo med navedenimi oblikami vitamina A in eksperimentalno najdenimi ter preverjali prisotnost prepovedane retinojske kisline v kozmetičnih izdelkih. V izbranih kozmetičnih izdelkih smo ugotavljali tudi vsebnost različnih oblik vitamina A in njihovo stabilnost pod vplivom različnih zunanjih dejavnikov. Ugotovili smo, da noben kozmetični izdelek ne vsebuje retinojske kisline. Navedbe posameznih oblik vitamina A na ovojnini pa se pri nekaterih izdelkih ne skladajo z eksperimentalno ugotovljenimi. Pri nobenem izdelku, ki ima točno navedeno vsebnost retinoidov, se vsebnost ni ujemala, pri enih so vsebnosti manjše, pri drugih pa celo večje. Ugotovljene vsebnosti retinoidov smo primerjali tudi s ceno kozmetičnega izdelka in ugotovili, da je cena le delno povezana z vsebnostjo vitamina A in posledično kakovostjo izdelka. Stabilnost različnih oblik vitamina A v kozmetičnih izdelkih smo v nadaljevanju preverjali z dolgoročnimi, pospešenimi in stresnimi testi. Izbrane izdelke smo izpostavili višji temperaturi (40°C) za en mesec in eksperimentalno ugotovili, da v večini izdelkov pride do določene stopnje razpada retinoidov in beta karotena, vendar slednjega v manjši meri. Pri dolgoročnem testiranju stabilnosti istih izdelkov, na sobni temperaturi in v temnem prostoru, smo potrdili kemijsko nestabilnost različnih oblik vitamina A. Nestabilnost je bila zelo obsežna v kozmetičnih izdelkih, ki so bili odprti že tri leta in shranjeni na sobni temperaturi. Pri izpostavitvi izdelkov ultravijolični svetlobi smo ugotovili, da je retinil palmitat zelo občutljiv na sevanje, retinol pa bistveno manj.

• Language: Slovenian
• Keywords: kozmetični izdelki, stabilnost, vsebnost, vitamin A, tekočinska kromatografija visoke ločljivosti
• Work type: Bachelor thesis/paper
• Organization: FFA - Faculty of Pharmacy
• Year: 2019
• PID: 20.500.12556/RUL-109436
• Publication date in RUL: 03.09.2019

Secondary language

• Language: English
• Title: Determination of content and stability of vitamin A and its derivatives in cosmetic products

Abstract

Vitamin A is a common active ingredient in cosmetics for mature skin and skin with acne. In cosmetics, the most common representatives of vitamin A are beta carotene, retinol, retinal and retinyl esters with saturated and unsaturated fatty acids. Retinoic acid is the only biologically active representative of vitamin A, but it is banned in cosmetics products. The purpose of this assignment was to determine the content of the most common vitamin A forms in cosmetic products using high-performance liquid chromatography. Therefore, 16 cosmetic products with at least one vitamin A form were selected and purchased locally. Considering the problem of under-control of cosmetic products, vitamin A forms listed on the packaging were compared to the experimentally found ones, in addition to detection of prohibited retinoic acid in cosmetic products. Furthermore, the content of found vitamin A forms was evaluated in the tested cosmetic products, along with their stability under different environmental factors. Retinoic acid was not found in any of the tested cosmetic products. However, the individual vitamin A forms listed on the packaging did not match the experimentally identified ones on certain cosmetic products. Also, none of products with defined retinoid content was consistent with the experimentally found content. Examination of found retinoid content and the price of cosmetic products revealed that the price is only partly an indicator of vitamin A content and consequently the quality of the product. The stability of the active components in cosmetic products was further verified by long-term, accelerated and stress testing. Selected products were exposed to higher temperature (40°C) for one month. The results revealed certain degradation of retinoids, and also beta carotene to a lesser extent in most of the tested products. Chemical instability of various vitamin A forms was also confirmed during long-term stability testing of the same products, stored at room temperature and in the dark for one month. Significant instability was also observed in cosmetic products that had been opened for three years and stored at room temperature. When products were exposed to ultraviolet light, retinyl palmitate, was found highly sensitive to radiation and retinol significantly less.

• Keywords: cosmetic products, stability, content, vitamin A, high-performance liquid chromatography