Pak. J. Pharm. Sci., Vol.29, No.1, January 2016, pp.173-178 173 Development of cetyl dimethicone based water-in-oil emulsion containing botanicals: Physical characteristics and stability Muhammad Khurram Waqas 1 *, Naveed Akhtar 1 , Pervaiz Akhtar Shah 2 , Muhammad Zeeshan Danish 2 , Arshad Ali Shah 3 , Valdir de Andrade Braga 4 and Barkat Ali Khan 1 * 1 Department of Pharmacy, Faculty of Pharmacy and Alternative Medicine, The Islaima University of Bahawalpur, Pakistan 2 University college of Pharmacy, Punjab University, Lahore, Pakistan 3 School of Pharmacy, University of South Asia, Lahore, Pakistan 4 Laboratory of Biotechnology, Federal University of Paraiba, João Pessoa, Brazil Abstract: The aim of current research was to develop a water-in-oil emulsion containing grape seed extract for application in cosmeceuticals. Finally grinded dried grape seeds powder was extracted with hydro alcoholic mixture. Emulsions consisting of different concentrations of cetyl dimethicone (Abile EM90), the nonionic emulsifier, liquid paraffin as oily phase and water as aqueous phase were developed. Color, odor, pH, viscosity, liquefaction, phase separation, centrifugation and thermal stability of the formulated emulsions were observed at various storage temperatures i.e. 8±0.5°C, 25±0.5°C, 40±0.5°C and 40°C±0.5°C with 70% RH. The stable formulation consist of 16% mineral oil, 4% of ABIL EM 90 ® , 4% grape seeds extract, 1% rose oil and 75% distilled water. All the results derived from this study showed good stability over the three months study period which indicates w/o emulsion can be used as carrier of 4% grape seeds extract to enhance desired effects when applied topically. Keywords: Grape seed extract, w/o Emulsion, stability, pH, electrical conductivity, and rheology. INTRODUCTION The choice of emulsifier is crucial not only for the formation of the emulsion but also for its long-term stability. Several classes of emulsion may be distinguished, namely oil-in-water (O/W), Water-in-oil and oil-in-oil (Boyd et al., 1972). Water-in-oil emulsions consists of the water phase, which is internal/dispersed phase, mixed with oil, which is continuous phase. This emulsion type is often more difficult to prepare and stabilize since it is most often based on totally non-emulsifiers. However recent advances in silicon chemistry and polymer chemistry have allowed preparation of excellent water-in-oil (W/O) emulsions (Saito & Shinoda, 1970). A real benefit of these vehicle emulsions is that they are readily spread on to the lipophilic skin and provide a film which is resistant to water wash off. This is how water resistant moisturizing cosmeceuticals are created (Waqas et al., 2010). Since the emulsifiers used for these emulsions are lipophilic, meaning oil loving, they do not upset the lipid bilayer and thus will not damage the skin barrier. The W/O systems are formed, using nonionic emulsifier, where the oil is expected to be an external phase. A wide variety of emulsifiers are used in pharmacy and cosmetics to prepare cosmetic emulsions. Nevertheless, these emulsifiers are often responsible for allergies and irritations. Therefore it is very important to develop formulations of cosmetic emulsions with emulsifier that do not cause allergies and irritations (Rousseau, 2000). A non-ionic emulsifier that is Polysiloxane polyalkyl polyether copolymer commonly known as ABIL EM 90 ® has been used as an emulsifying agent, which finely distribute the water droplets into the continuous oil phase. ABIL EM 90 ® is clear and viscous oil soluble liquid having the HLB value equal to 5. It is widely used as emollient and anti-foaming agent in the cosmeceutical emulsions. It has high compatibility with active ingredients and form very stable formulations (Ali et al., 2012). Botanical extracts form the largest category of cosmeceutical additives found in market place today. They can be easily added to cleansers, moisturizers, astringents, treatment creams, colored cosmetics and face masks (Allemann & Baumann, 2009). Botanical extract for topical applications are considered safe by US food and drug administration, thus allowing the products to be marketed without obtaining status or being restricted by monographed ingredients. Today cosmetic formulators have access to plant material worldwide for incorporation into cosmeceuticals (Aburjai & Natsheh, 2003). Grape seed (Vitis vinifera) is indigenous to southern Europe and Western Asia and is cultivated today in all temperature regions of the world. Grape seeds contain several active botanicals like flavonoids, polyphenols, anthocyanins, proanthocyanidins, procyanidines, and the stilbene derivative resveratrol (Ricardo et al., 1991). Grape seed applied topically improved cutaneous photo protection to UVB, inhibits histamine synthesis and promotes wound healing. Grape seed protects *Corresponding author: e-mail: mkhurramwaqas@gmail.com, barki.gold@gmail.com