J. Cosmet. Sci., 66, 359–370 (November/December 2015) 359 Feasibility study of a cosmetic cream added with aqueous extract and oil from date (Phoenix dactylifera L.) fruit seed using experimental design FATMA LECHEB and SALEM BENAMARA, Research Center in Physicochemical Analysis, Bou-Ismail, 42004, Tipaza (F.L.), and Research Laboratory in Food Technology, Faculty of Engineering Sciences, University M’hamed Bougara, Boumerdès, 35000, Algeria (S.B.). Accepted for publication July 26, 2015. Synopsis This article reports on the feasibility study of a cosmetic cream added with aqueous extract and oil from date (Phoenix dactylifera L.) fruit seed using experimental design. First, the mixture design was applied to optimize the cosmetic formula. The responses (dependent variables) were the spreadability (YSp) and viscosity (YVis), the factors (independent variables) being the weight proportions of the fatty phase (X1), the aqueous date seed ex- tract (X2), and the beeswax (X3). Second, the cosmetic stability study was conducted by applying a full factorial design. Here, three responses were considered [spreadability (Sp), viscosity (Vis), and peroxide index (PI)], the independent variables being the concentration of the date seed oil (DSO) (x1), storage temperature (x2), and storage time (x3). Results showed that in the case of mixture design, the second-order polynomial equations correctly described experimental data. Globally, results show that there is a relatively wide composition range to ensure a suitable cosmetic cream from the point of view of Sp and Vis. Regarding the cosmetic stability, the storage time was found to be the most infl uential factor on both Vis and PI, which are considered here as indica- tors of physical and chemical stability of the emulsion, respectively. Finally, the elaborated and commercial cosmetics were compared in terms of pH, Sp, and centrifugation test (Ct). INTRODUCTION Numerous works are devoted to the valorization of date (Phoenix dactylifera L.) seeds (DS) under different forms: activated carbon (1), livestock feed (2), preparation of citric acid and proteins (3), and uses in traditional medicine (4), knowing their antimicrobial and antiviral properties (5). Address all correspondence to Salem Benamara at sbenamara2001@yahoo.fr. Presentation: The fi rst version of the content of this article was presented as oral communication at the 3rd International Conference on Mathematical Modeling in Physical Sciences, Madrid, Spain, August 28–31, 2014.