The most popular sunscreen vehicles are
lotions and creams. Two-phase oil-in-water or water-in-oil emulsion systems
allow for the widest variety in formulation. Most sunscreen ingredients are
lipid soluble and are incorporated into the oil phase of the emulsion. Higher
SPF products may contain from 20-40% sunscreen oils, accounting for the
occlusive greasy feel of many of these products. “Dry lotions,” often
marketed as sport lotions, represent the formulator's attempt to provide a less
Other vehicles for organic sunscreen ingredients include gels, sticks and aerosols. Water- or alcohol-based gels provide less greasy aesthetics but rely on the more limited number of water soluble sunscreen ingredients and are less substantive with a greater potential for irritation. Sticks readily incorporate lipid-soluble sunscreens thickened with waxes and petrolatum and are heavier on application, but they are useful for protecting limited areas such as the lips, nose or around the eyes. Aerosols provide some convenience on application but may be difficult to apply evenly, resulting in a discontinuous film.
Over the last decade sunscreens have been incorporated into a broader range of consumer products including daily use cosmetics. The FDA monograph now distinguishes between beach and non-beach products. The availability of sunscreens in this fashion offers many advantages. Daily protection is facilitated for a large segment of the population. UV protection is encouraged by the “glamour” image associated with cosmetic use. Sunscreen/moisturizers are available all year round, as opposed to seasonal beach products. Moisturizers incorporating sunscreen are generally oil-in-water emulsions. Water-soluble sunscreen ingredients are often used to decrease the oil phase and increase cosmetic elegance. Foundation makeup without sunscreen generally provides a SPF of 3 or 4 by its pigment content. By raising the level of pigments, including inorganic sunscreen particulates, titanium dioxide and zinc oxide, higher SPF can be achieved with or without the use of organic chemical sunscreens. Makeup with sunscreen has intrinsic full-spectrum UVA protection based on opacity. Lipsticks generally add chemical sunscreen to provide enhanced SPF protection.
Click here for references.