WILD PLUM IN COSMETIC FORMULATIONS 285 ( p 0.05). However, comparisons between images without Wild Plum compared to images with Wild Plum were statistically signifi cant ( p 0.05). In many cases, inclusion of Wild Plum made a very signifi cant ( p 0.001) visual difference on the visual monadic scale. The cosmetics industry uses nearly insoluble or encapsulated materials in order to protect color and luminosity (22,23). However, caking can become a problem with insoluble particles, and if encapsulation is used, sacrifi ce of color may occur. Hence, the need per- sists for cosmetic formulations that not only hide the appearance of wrinkles and lines, but also enhance the glow of youthful skin. Wild Plum is insoluble in water, oil, and other common solvents used in cosmetic formulations, but can be solubilized in detergents like SDS (sodium dodecyl sulfate) and nonionic surfactants like Triton-X100, allowing easy removal from skin by washing with soapy water. Caking does not occur with Wild Plum, as low concentrations are able to give the desired effect. This allows for optimal formula- tion conditions, as washing away or leaching of Wild Plum becomes irrelevant. Thus, the new photoluminescent Wild Plum is versatile in application and has been designed to eliminate dullness or the lack of luminosity often seen in aged and photodamaged skin (4). WILD PLUM VERSATILITY The Wild Plum compound is photoluminescent, displaying a glow of intense blue color. In Figure 5, a gradient of blue fl uorescence is apparent when Wild Plum is formulated into a commercial foundation at different concentrations. Wild Plum was also co-mixed with light-scattering materials that have refractive indices close to that of skin at 1.5–1.6 for the “soft-focus effect” (17,18). Such materials include talcum powder, titanium dioxide, barium sulfate, and pearlescent pigments. Each pow- der can be used independently or combined to create unique shades specifi c to the desired application. The versatility of Wild Plum affords incorporation into a variety of cosmetic formulations without affecting the consistency, thickness, viscosity, or color of the formu- lation. Figure 5 also shows that Wild Plum can be used at concentrations as low as 0.02%, which shows that it can be used in existing formulations without signifi cantly changing their properties after addition. Figure 5. (Left) Wild Plum powders in different shades of color. (Right) Intense blue fl uorescence of Wild Plum incorporated into commercial foundation at 2%, 0.2%, 0.02%, and the control commercial foundation without Wild Plum (from left to right) excited at 365 nm with a UV lamp.

JOURNAL OF COSMETIC SCIENCE 286 WILD PLUM PARTICLE SIZE Particle size analysis data obtained by scanning electron microscopy showed that the amorphous particles ranged from 2.19 μm to 23.63 μm when mixed with talcum powder. (Figure 6). This makes Wild Plum ideal for toiletries, and avoids the range associated with toxicity and the biological effects of nanometer-sized particles (24,25). Furthermore, par- ticle sizes between 2 μm and 20 μm provide good color properties and soft-focus effects (17). Depending on the intended use, the preferred average diameters will vary, based on desired granularity and texture. For example, a liquid facial cosmetic formulation com- prising a fl uorescent whitening agent as described above has a preferred particle size range of between 10 μm and 30 μm. A lipstick formulation containing Wild Plum should be formulated with particle sizes between 2 μm and 20 μm. Furthermore, admix- ing Wild Plum in a 2% concentration by ball-milling in micronized talcum powder does not cause aggregation to larger particle sizes. WILD PLUM SYNTHESIS The synthesis of Wild Plum is still proprietary. However, the compound was synthesized according to similar procedures published in United States patent application 11/863,475 (fi led in 2007). WILD PLUM, FDA REGULATIONS, AND SAFETY CONSIDERATIONS The FDA act exempts cosmetic ingredients from regulation except for sunscreens and color additives (26). A color additive is defi ned, essentially, as anything that imparts color. Wild Plum is considered a cosmetic ingredient that improves skin appearance, is not a color or dye, and thus does not require FDA certifi cation. However, Wild Plum is an off-white powder and can be mixed with colored FD&C dyes to suit a particular cosmetic formulation. For example, as seen in Figure 5, Wild Plum Pink was prepared by mixing Wild Plum with FD&C Red No. 40 and FD&C Red No. 3. A blue shade was achieved by mixing Wild Plum with FD&C Blue No. 1 to specifi cally decrease redness and dark cir- cles, enhance whiteness, and even out pigmentation, thereby increasing luminosity. Figure 6. (Left) Scanning electron microscopic image of zoomed-out Wild Plum particles demonstrating an aver- age particle size of 2–20 μm (bar = 500 μm). (Right) Image of individual Wild Plum particles (bar = 20 μm).