Pregled uporabljenih zgoščeval naravnega izvora v izdelkih certificirane naravne kozmetike ter vrednotenje senzoričnih lastnosti izdelanega hidrogela

Mervar, Iva (author), Kočevar Glavač, Nina (mentor)

Zgoščevala imajo v kozmetičnih izdelkih pomemben vpliv na lastnosti celotne formulacije. Njihovo uravnavanje reoloških lastnosti zagotovi ustrezno viskoznost, mazljivost in razporeditev kozmetično aktivnih sestavin po mestu delovanja. Zgoščevala, kot so polisaharidi, delujejo tudi kot kozmetično aktivne sestavine in imajo vlažilno delovanje. S trenutnim naraščajočim trendom naravne kozmetike potrošniki iščejo kozmetične izdelke, ki so biološko sprejemljivi za njihovo kožo in prijazni do okolja. S pregledom trga vodnih serumov z evropskim certifikatom Natrue smo ugotovili, da je najpogosteje uporabljeno zgoščevalo naravnega izvora v hidrogelih ksantan. Prisotnost negativnega naboja in močna sposobnost nabrekanja v vodnih sistemih sta razloga za njegovo pogosto uporabo. Ker zgoščevala omogočajo nastanek poltrdnega sistema, od katerega sta odvisni konsistenca in mazljivost, smo z izdelavo hidrogelov s štirinajstimi različnimi zgoščevali naravnega izvora in njihovimi kombinacijami subjektivno primerjali njihove senzorične lastnosti. Z najustreznejšimi kombinacijami smo nato izvedli pospešene teste stabilnosti, kjer smo pri različnih pogojih shranjevanja opazovali spremembo njihovih organoleptičnih lastnosti in vrednosti pH. Najstabilnejšo kombinacijo ksantana in karagenana smo nato uporabili za izdelavo lastnega vodnega seruma. S placebom kontrolirano raziskavo na 25 prostovoljcih smo nato polimerom vrednotili njihove senzorične lastnosti ter stanje kože po uporabi. Pripravili smo dve formulaciji hidrogela, v katerih smo uporabili enako kombinacijo zgoščeval in lastno izdelan hidrolat pelargonije. V testni hidrogel smo vgradili suhi izvleček lesa bele jelke, ki smo ga pridobili z liofilizacijo izvlečka, pridobljenega z ekstrakcijo s subkritično vodo. Izvleček smo vgradili v 0,3-odstotni koncentraciji. Placebo hidrogel ni vseboval izvlečka. Hidrogele so subjektivno vrednotili prostovoljci, ki niso vedeli, kateri serum vsebuje izvleček in kateri je placebo. S pomočjo vprašalnika so ocenili, da se seruma senzorično bistveno ne razlikujeta, oba delujeta vlažilno in da je serum z izvlečkom pripomogel k izboljšanju stanja njihove kože. Kot bogat vir polifenolov ima izvleček bele jelke z antioksidativnim in protivnetnim delovanjem velik potencial uporabe v kozmetiki.

• Language: Slovenian
• Keywords: hidrogel, izvleček bele jelke (Abies alba), ksantan, zgoščevala naravnega izvora
• Work type: Bachelor thesis/paper
• Organization: FFA - Faculty of Pharmacy
• Year: 2021
• PID: 20.500.12556/RUL-129915
• Publication date in RUL: 09.09.2021

Secondary language

• Language: English
• Title: Review of natural-origin thickeners used in certified natural cosmetics and evaluation of sensory properties of a custom made hydrogel

Abstract

Thickeners in cosmetic products have a significant effect on the properties of a final formulation. Their regulation of rheological properties ensures adequate viscosity and distribution of cosmetically active ingredients. Thickeners such as polysaccharides also function as cosmetically active ingredients and express a moisturising activity. With the current growing trend of natural cosmetics, consumers are looking for products that are biologically acceptable to their skin and environmentally friendly. By reviewing the market of aqueous serums with the European Natrue certificate, we found that the most commonly used thickener of natural origin is xanthan. Its anionic nature and strong swelling capacity in aqueous systems justify its wide use. Since thickeners enable the formation of a semi-solid system, on which the consistency and lubricity depend, we compared the sensory properties by making of hydrogels prepared using 14 different thickeners of natural origin and their combinations. Accelerated stability tests were then performed with the most appropriate combinations, where changes in their organoleptic properties and pH were examined under different storage conditions. The most stable combination of xanthan and carrageenan was further used to make our own aqueous serum. In a placebo-controlled study on 25 volunteers, we then evaluated the sensory properties of serums and skin condition after their use. We prepared two formulations of hydrogels with the same combination of thickeners and a geranium hydrolate. In the test product, we incorporated a dry silver fir wood extract, which was obtained by lyophilisation of a subcritical water extract. The extract was used at a 0.3 concentration. The placebo hydrogel didn’t contain the extract. With the help of a questionnaire, the hydrogels were evaluated by volunteers who did not know which serum contained the extract and which was the placebo. Based on the results, the serums do not differ significantly in terms of their sensory properties, both have a moisturizing effect and the serum with the extract helps to improve the condition of the skin.

• Keywords: hydrogel, silver fir extract (Abies alba), thickeners of natural origin, xanthan