Toner claims are substantiated by subjective and objective measurements. Many claims are substantiated by using both measurements. These tools are useful in the screening of ingredients and final product efficacy. Subjective measurements include consumer perception testing and panelists self-assessment on clinical trials. These tests include yes/no, like/dislike, agree/disagree, and point scales to rate consumer perception. Point scales may be a three-, five-, seven-, or 10-point scale. For example, using a five-point scale of “much worse,” “slightly worse,” “no change,” “slightly improved,” or “much improved” would offer the panelists the option to rate the skin’s appearance and condition. Another method is the use of a line marked in units from one to 10 designating least to most, where the panelists mark product attribute agreement.
Objective measurements include expert grading, photography, and instrument measurements. The expert grader is trained in visually assessing the skin for changes in color for evenness of skin tone, reduction of pore size for tightening and astringent claims, and reduction of the appearance of fine lines and wrinkles for anti-aging claims. Photography and more recently VISIA CR™ is used to capture these same measures on a permanent record. Instrumental measures include the Sebumeter™ and Sebutape (CuDerm Corporation, Dallas, TX) (Fig. 1) to measure oil control. The Gas Bearing Electrodynamometer™ assesses skin softness, and the Minolta chromameter measures skin tone and color. Chromameter measurements are useful in measuring skin tone and color in products claiming evenness of skin tone or skin whitening as well as the reduction of redness when measuring anti-irritant and anti-inflammatory benefits.