Gülay BÜYÜKKÖROĞLU , Sefa AVCIER , Yasemin YAZAN

1. COMPARISON OF COSMETIC W/O EMULSION SYSTEMS CONTAINING ZIZYPHUS JUJUBA AND ERYTHRAEA CENTAURIUM EXTRACT Gülay BÜYÜKKÖROĞLU, Sefa AVCIER, Yasemin YAZAN Anadolu University, Faculty of Pharmacy, Department of Pharmaceutical Technology 26470 Eskişehir- TURKEY INTRODUCTION Plant materials are being widely used in cosmetic products during the last 30years. Some plants and materials of plant origin, acting as skin anti-aging with different mechanisms are among the primary cosmetic active agents studied. Almond oil was used as the oily external phase of the emulsions owing to its skin moisturizing, softening and non-irritant properties. Phenolic groups exhibit activity as radical scavengers and/or metal chelators (1) In this study, mixture of almond and silicon oils was used as the continuous phase and cethyl dimethicone copolyol was used as the lipophilic surfactant for the formation of a w/o emulsion system. 2% and 4% lyophilized extracts obtained from the leaves of E. Centaurium and Z. Jujuba were incorparated into the W/O emulsion system. Three different emulsion systems containing 2% and 4% plant extracts and without containing the extract were prepared and their characteristics and efficacies were compared. One formulation was prepared without the incorporation of the extract, for comparison. All formulations prepared were of homogeneous cream consistency. Plant extract of Zizyphus jujuba was found to inhibit lipid preoxidation and to havefree radical scavengering effect (2). Fresh Zizyphus jujuba contains primarily proanthocyanidines (3). Benefits of proanthocyanidines on dermatological signs of aging are presumably based on their antioxidant effects. Erythraea centaurium contains considerable amounts of polyphenolic compounds. By virtue of effectively scavenging deleterious radicals and suppressing radiation induced oxidative reactions, the phenolic compounda may serve an important antioxidant function in preserving the physiological integrity of cells, such as skin cells, exposed to both air and UV radiation (4). MATERIALS Almond oil (Detsan, Turkey) Zizyhus jujuba plant (Sivrihisar, Turkey) Erythraea centaurium plant (Balıkesir, Turkey) Cetyl dimethicone copolyol (Abil EM 90) Silicone oil (Abil 350) (Goldschmidt A.G., Germany); Vitamin E (Johnson&Johnson, Turkey) Methyl paraben (Nipagin M) (Johnson&Johnson, Turkey) EDTA (E.Merck, Germany) Magnesium sulfate (E.Merck, Germany) Sodium chloride (E.Merck, Germany) METHODS Ingredients Used in the Preparation of Emulsions Characterization and Stability of the w/o Emulsion Systems Macroscopic analysis Color, consistency, appearance and homogeneity were controlled. Determination of the emulsion type External phase of the emulsion was determined by dilution using both water and oil. Globule size distribution Emulsion systems were dispersed in almond oil and their globule sizes were examined using particle size analyzer. pH value measurement pH values of the aqueous phases of all emulsions were measured using a pH-meter. Microscopic analysis Following dilution with almond oil, the emulsion systems prepared were examined under 100X and 40X magnification and their photographs were taken. Centrifugation Freshly prepared and 24-hour old emulsions were centrifuged. Thermal stability tests Freshly prepared w/o systems were kept at 40C±10C, room temperature (200C±10C) and 400C±10C, and investigated for possible phase separation or visual microbial contamination. Microbiological test Formulations incubated at 370C for seven days were inoculated in Eosin Methylene Blue Agar and Saburaud Dextrose Agar media and samples were taken at different intervals. Rheological test Rheological tests were performed at 200C±0.10C using a rheometer with cone-plate geometry. Dermatological Studies 20 female volunteers, refrained from using any moisturizer, sunscreen or liquid make-up 1 week prior to study, were used. Each product was applied to the cheeks and forearms for the 24-hour measurements and to the entire face twice a day for a 4-week study. Skin moisture and sebum were measured for 24 hours; and facial (forehead and cheeks) pH, moisture, sebumand elasticity were measured once a week, for a duration of 4 weeks.The data obtained was evaluated statistically using SPSS program on the computer (5). EXPERIMENTAL Results and Discussion pH values of the formulations ZJ0, ZJ1 and ZJ2 were 5.3, 4.7 and 4.3, respectively, which are appropriate for application to the skin. All the emulsion formulations exhibited emulsion characteristics in microscopic examination. Upon centrifugation, no phase separation was observed for the freshly-prepared and 24-hour old emulsions. Considering the skin elasticity, skin sebum content and skin moisture, EC2 and ZJ2 formulations were found to be effective. On the contrary to the antioxidant and anti-aging effects ofZizyphus jujuba and Erythraea centaurium extracts (2,4), no significant data could be obtained for the skin. Conclusion Stable emulsion formulations containing Zizyphus jujuba and Erythraea centaurium extracts could be prepared and were found to remain stable during the storage time of 6 months under different conditions. The aim of this study was the enhancement in skin elasticity, skin sebum content and skin moisture with Zizyphus jujuba and Erythraea centaurium extracts. Data obtained showed increase in different skin values, however this increase was of no statistical significance. In spite of the scientific fact that Zizyphus jujuba and Erythraea centaurium extracts both have antioxidant and anti-aging effects, this fact could not be determined for the formulaions obtained in this study. This may be most probably due to the partial loss in the active ingredients of Zizyphus jujuba and Erythraea centaurium during the extraction procedure. References [1]P. Valentao, E. Fernandes, F. Carvalho, P.B. Andrade, R.M. Seabre and M.L. Bastos, J.Agric. Food Chem., 49 (7), 3476-3479 (2001. [2] W. Wang, W.W. Chen, C. Hsi, I. Chieh Ho, T. Chih, 11 (3), 159-161 (1991). [3] Z.A. Kuliev, A. Malik, U.A. Akhmedov, A.D. Vdovin, Proceed. 2nd SCNC, 38, 1996. [4] E. Graf, Free Radical Biology and Medicine,13 (4), 435- 448 (1992). [5] G. Büyükköroğlu, Y. Yazan, Turk.J.Pharm.Sci., 1 (1), 31- 46 (2004).