J. Soc. Cosmet. Chem., 29, 91-98 (February 1978) The panel study as a scientifically controlled investigation: moisturizers and superficial facial lines ELIAS W. PACKMAN*, Philadelphia College of Pharmacy and Science, 43 rd Street, Woodland Avenue and Kingsessing Mall, Philadelphia, PA 19104 and EUGENE H. GANS**, Dermatology/Toiletry R&D, Vick Divisions Research and Development, One Bradford Road, Mount Vernon, NY 10553. Received June 14, 1977. Synopsis Characteristic features of the CONTROLLED STUDY (randomized treatment, comparison agent, blinded evaluation) were incorporated into a panel investigation of the objective effects of five topical MOISTURIZERS, water, or no treatment on SUPERFICIAL FACIAL LINES, as perceived by a 12- member untrained CONSUMER EVALUATION PANEL, assessing the skin of a separate group of subjects who used the test materials. The method proved sufficiently sensitive in almost 900 single-blind, half-face comparative evaluations to demonstrate that: 1. Under the conditions of the scientific investigation, a consumer panel composed of normal users who have not been trained as professional evaluators can detect and visually evaluate the effect of moisturizers on other consumers, thereby providing an important estimate of consumer relevance to cosmetic perfor- mance. 2. The technique is sensitive enough to detect the differing degrees of performance that existed among the various treatments. 3. Three of the five moisturizers studied were significantly superior to water, which in turn was assessed more favorably than no treatment. 4. The extent of effectiveness existing for a particular cosmetic tended to prevail throughout the study group and was not concentrated in particular subjects. INTRODUCTION The evaluation of a cosmetic preparation, whose benefit is to be perceived by the user, gives rise to a distinctive problem for the investigator. This is different from the clinician's problem of confirming objectively an effect on an organic malfunction, perhaps a condition improved by an action not readily perceived subjectively by the *Professor in Pharmacology. **Vice President & Director. 91

92 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS patient. The cosmetic scientist seeks to confirm the existence of an objectively existing benefit, but it must be a benefit subjectively evident and relevant to consumers, and yet it is to be demonstrated in a scientifically viable manner. A variety of approaches contributing to resolution of this problem has been developed by previous investigators. For example, decreased moisture loss following the applica- tion of creams or lotions has been measured objectively with desiccator assembly strapped against the inner forearm and consisting of a capped glass cylinder containing silica gel (1). Changes in roughness and dryness of the hands after use of a lotion have been assessed by an expert observer with a subjective scoring system, supplemented by the opinions and preferences of panel members (2). The effects of emollients, soaps, and water on three components of smoothness have been evaluated instrumentally via measurement of friction with a dynamometer, of topography with stylus displacement, and of scratch hardness with a variable-load stylus (3). The dynamometer has also been used to measure viscoelastic properties of skin in vivo and in vitro, following applica- tion of water, water vapor, or an emollient, through the skin's response to shearing stress, as displayed in hysteresis loops on an oscilloscope screen (4). A single-blind study of baby oil as a moisturizer on subjects selected for rough or scaly skin of the el- bows, knees, heels, and tibia involved evaluation by a clinical investigator with a five- point rating scale, together with review of photographs for some subjects (5). Our particular objective was to investigate the hydrating effect of topical moisturizers on the stratum comeurn, as perceived via their action on superficial facial lines, the kind of shallow to very shallow "dry-lines," not affecting the dermis, that an effective moisturizer can be expected to minimize temporarily. The term "wrinkles" is broadly used by the general population to include these lines. In accordance with this usage, a recent article on cosmetic dermatology, categorizing surface changes in the facial skin by age, describes all such manifestations as "wrinkles" (6). However, in order to best delineate the area of performance of interest to us, we selected "superficial facial lines" (SFL's) as contrasted to the more pronounced wrinkles, with a deeper, dermal involve- ment. The solution described below, to the problem of defining subjectively perceived effect on such lines in objectively valid terms, consisted of designing and conducting a panel study as a controlled scientific study with its features of randomized treatment, a com- parison agent, and blinded evaluation. To provide relevance, this evaluation was performed by a nonprofessional and untrained consumer panel acting as the investiga- tors not ofefj•cts on themselves, as in the classic consumer test, but on a separate group of subjects who used the test materials. Our dual objectives were: 1. to ascertain the feasi- bility of a panel of consumers functioning effectively within the structured format of the scientific investigation, and 2. to determine the extent to which the effects of five moisturizers [previously observed as having differing degrees of performance by expert judges (7)], water, or no treatment were perceptible to these consumer-investi- gators. EXPERIMENTAL The central consideration in defining the investigational procedure was to keep it within the capabilities of nonprofessional evaluators, while adhering to the require- ments of a controlled study.