Fragrance is a significant part of personal care products such as creams, lotions, body powders and shaving creams. It is formulated into nearly every personal care product via either a single raw material or a blend of two or three materials. Fragrance also plays a minor role in other cosmetics such as depilatories and hair-waving lotions, where it primarily masks malodorous ingredients. Fragrances are volatile; they react with other components and are susceptible to heat, moisture and various other factors. Therefore, it is important to control the release of fragrance raw materials over a desired site and at a desired rate.
Before a fragrance is incorporated into a cosmetic preparation, it is blended by a perfumer who mixes a variety of natural and synthetic raw materials to create a perfume compound with a multitude of chemical functional groups such as alcohols, aldehydes, ketones, esters, lactones, ethers and nitriles. In some cases, natural ingredients are less potent than their synthetic counterparts but on the other hand, only low levels of synthetic ingredients are permitted. In either case, it may be difficult to achieve the desired fragrance in a final product without adding high levels of ingredients. To increase the efficacy of fragrance raw materials, controlled release may be used. This novel technology improves the performance of natural ingredients, thereby offering a viable alternative to less accepted synthetic ingredients.
Lab Practical: Using Controlled-release Systems
- Choose the appropriate wall material: one that is compatible with the formulation's ingredients.
- The proper wall to core ratio must be selected, as it determines the encapsulation efficiency.
- The core and wall material should be non-reactive to one another.
- Formulators should decide up front the mechanism of release and the controlled-release technique.
- Adding colors to the encapsulates can impart interesting effects in formulations.