Kinetic investigation of some dermatological skin care products in lipid oxidation environment

KINETIC INVESTIGATION OF SOME DERMATOLOGICAL SKIN CARE PRODUCTS IN LIPID OXIDATION ENVIRONMENT HÜSEYİN KASTRATİ KASTAMONU UNIVERSITY INSTITUTE OF SCIENCE DEPAERTMENT OF ENVIRONMENTAL ENGINEERING SUPERVISOR: ASSİST PROF. DR. TEMEL KAN BAKIR The human body is exposed to UV rays throughout the day, and this accelerates the formation of reactive oxygen species (ROS), which can react easily on the skin, the largest organ of man. In order to stop the harmful effects of these species, which are among the causes of many diseases including cancer, antioxidant additives are used in cream formulations. Many in vitro and in vivo studies have been created to illuminate the physicochemical properties of cream formulations. In this study, antioxidant activity and capacity determinations of four different cream samples sold as industrial skin care products were performed using oil / water emulsion as well as phospholipid-containing oil / water emulsion medium for simulating the skin oxidation environment. This study examined in three different sections; In the first part, the effects of linoleic acid (LA) emulsion oxidation in the presence of pH 5.5 and 35 ° C Cu (II) using ferric thiocyanate (Fe (III) SCN) method and thiobarbutyric acid (TBARS) method; In the second part, it was carried out using 1,1-diphenyl-2-picrylhydrazyl radical scavenging (DPPH) method for antioxidant activity determinations of cream samples. In the third part, the effect of cream samples on UV B (50 uW / cm2, 306 nm) induced phospholipid-containing oil / water emulsion oxidation were investigated by using Fe (III) SCN method and conjugated diene determinations simultaneously. At the same time gas chromatography (GC-MS) for determination of fatty acid contents during oxidation was used. Accordingly, it was determined that sample 1 and sample 2 cream samples inhibited primary and secondary products from oxidation products, while sample 3 and sample 4 showed pro oxidant properties. The same results for the samples were confirmed by the DPPH method. In the kinetic examinations performed in the skin simulation environment, the velocity constants for the primary oxidation products followed the order of sample 4> sample 3> Control Group> sample 1> sample 2. In terms of conjugated diene formations, the development phase of oxidation for sample 4 after about 50 minutes; for sample 3 after about 70 minutes; for samples 1 and 2, it was observed that it started after about 140 minutes. In concurrent GC-MS analyzes, it was observed that the breakdown of fatty acids 17 and 19 carbon acids into secondary products with low carbon levels in the development phase of oxidation was less in cream samples 1 and 2 compared to cream samples 3 and 4. KEYWORDS:UV B radiation, antioxidant, ferric thiocyanate (fe (iii) scn) method, conjugedien method, skin model emulsion. 2020, Page, ..... Science Code: 201