Development of Soy Isoflavone Body Scrub Formulations

Abstract

Abstract

Introduction: Isoflavones are more attention in cosmeceuticals regarding the skin care benefit effects. Scientific evidences demonstrated the potential use of isoflavones in the prevention and treatment of numerous skin disorders such as skin aging, cellulite, acne and sensitive skin. Recently, scrub products have gained popularity and gradually grown in the mass market. Moreover, scrub products provide cleansing and skin rejuvenation benefits. Therefore, the objective of this study was to develop the soy isoflavone body scrub formulations contained soybean extract and powder of soybean seed. Materials and Method: Isoflavones were extracted from soybean powder by using ethanol-water system. After isoflavone extraction, the soy powders were dried and sieved.  The oil in water emulsion base with optimum viscosity and good skin hydration effects was formulated and prepared by using beaker method. The soy isoflavone body scrubs containing soy extract and soy powder were prepared. The physical appearance, pH, viscosity, and physical stability of soy isoflavone body scrubs were determined.  Results: The pH and viscosity of emulsion base were 7.77 ± 0.03 and 2.19 ± 0.20 x 10⁶ cps, respectively. Incorporation of soy isoflavone and powder of soybean seed significantly decreased the pH value, but had insignificantly effect on the viscosity of the emulsion base. The developed soy isoflavone body scrubs had a good physical stability at accelerated, heating (45°C, 24h) and cooling (2°C, 24h) for 6 cycles, and at ambient conditions (3 month). No phase separation or bleeding occurred. The pH and viscosity did not change significantly. The preliminary sensory assessment in 14 healthy volunteers revealed that sizes and amount of soy powder in soy isoflavone scrubs affected their preferences.  Conclusion: The developed soy isoflavone body scrub formulations had a good appearance and physical stability. Further studies regarding the chemical stability of soy isoflavones in the scrub formulations, as well as the efficacy evaluations such as skin hydration shall be performed.