Preparation of a new soft capsule for cosmetics

A novel microcapsule for cosmetics was studied. The microcapsule was prepared by using an O/W/O emulsification technique and showed high thermostable properties (> 70°C). Agar was employed to gel the water phase of the emulsion. The size of the microcapsules was controlled by the process temperature and the stirring speed: the higher the temperature or the stirring speed, the smaller the diameter of the microcapsule produced. The strength of the agar gel phase was investigated, and the effect of the ratio of the internal oil to the gel (water) phase was observed. Young's modulus decreased with increase of the internal oil ratio. For cosmetic applications of the microcapsules, the all trans-retinol palmitate or ethyl linoleate used as a model ingredient was stabilized by microencapsulation. The remaining percentages of all trans-retinol palmitate and ethyl linoleate in the microcapsule after the four-week experiments at 50°C were 87% and 95%, respectively. On the other hand, those in oil solution were 72% and 91%, respectively. This microcapsule shows suitable properties for not only cosmetic use, but also for applications in foods and other products.