J. Soc. Cosmet. Chem. 24 3141 (1973) ¸ 1973 Society of Cosmetic Chemists of Great Britain The evaluation preparations of hand-care I. M. GIBSON*t Presented on the 11th April 1972 in Oxford, at the Symposium on 'Skin--Environmental responses and protection', organized by the Society of Cosmetic Chemists of Great Britain. Synopsis---A METHOD is described in which an expert observer assesses changes in HAND CONDITION using a subjective SCORING SYSTEM. A TRIAL is reported in which the PERFORMANCE of a hand LOTION containing a plant extract was compared with a control lotion. Regular use of a hand lotion improves skin condition, especially for people whose hands are initially in poor condition. Changes in the WEATHER also affect hand condition. Panel members' own opinion of product performance showed that they noticed an improve- ment in hand condition, and was also of value for assessing overall product acceptability to the consumer. INTRODUCTION Rough, dry skin is a common condition of the hands which is par- ticularly prevalent during the winter months. A frequent cause of this con- dition is repeated contact with water during cold, dry weather, that is when the skin temperature is likely to be low and the ambient relative humidity is also low (1, 2). Contact with detergents and other household materials can aggravate the condition (2, 3). Dry skin both looks and feels different from skin in good condition due to (a) roughness and flakiness of the skin surface, (b) cracking of the horny layer, sometimes accompanied by underlying inflammation, (c) inflexibility of the horny layer, which con- tributes to the feeling of roughness. *Unilever Research Laboratory, 455 London Road, Isleworth, Middlesex. ?Present address: Western Australia Institute of Technology, Perth, Australia. 31

32 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS In the area of hand-care preparations we are concerned mainly with emollient creams and lotions which satisfy a definite consumer need for the prevention or treatment of rough, dry skin. Thus, when evaluating the per- formance of emollients we are primarily interested in changes in the con- dition of hand skin, over a period of time, related to usage of the product. Whilst skin in either good or very bad condition is easily recognizable it is not easy to quantify those intermediate conditions of dryness which are most readily amenable to treatment with emollients. There are a number of ways of approaching the evaluation of hand-care products and materials. Techniques using isolated stratum corneum are of value in the determination of the effects of various materials and environ- mental conditions on the mechanical behaviour of stratum corneum in relation to its water-binding properties (4-7). However, these methods need to be followed by in vivo tests in order to assess the effects of particular sub- stances on skin under in-use conditions. The choice of evaluation technique for in vivo assessment is difficult to make. The main advantage of instrumental methods of measurement is their apparent freedom from operator error, and a few methods have been reported for measuring certain superficial properties of skin in vivo. Surface topography has been measured by taking silicone rubber replicas of the skin surface. The replicas are photographed under different lighting con- ditions (8, 9), but it is not easy to obtain quantitative data from the photo- graphs. Prall (10) has measured the cohesion of the surface cells of the horny layer as an indication of the degree of scaliness of the skin. Attenuated total reflectance has been used to study deposition and removal of materials from the skin surface, and to show differences in the hydration of the stratum corneum (11). The main disadvantage of instrumental tech- niques lies in the difficulty of correlating them with the subjective assess- ment of skin properties. This is particularly true of the complex set of pro- perties displayed by rough, dry skin, which cannot be adequately measured by any single instrument. For this reason, the evaluation of hand-care pre- parations is probably best carried out using an expert observer to assess hand condition at intervals during the course of a trial. This approach can, of course, be used to evaluate harmful, as well as beneficial, effects of ma- terials on skin condition for example, it has been employed to examine the effects of various soaps and detergents on housewives' hands (12, 13). The purpose of this paper is to describe a technique for assessing hand condition and, as an illustration of its use, to give an account of a trial in which two hand lotions were compared for effectiveness on a relatively