J. Cosmet. Sci.} 55, 157-162 (March/April 2004) Lack of burning and stinging from a novel first-aid formulation applied to experimental wounds A. PAGNONI, G. SPINELLI, R. S. BERGER, J. BOWMAN, S. GARREFFA, and A. M. SNODDY, Hill Top Research, Inc., 388 Ryders Lane, Milltown, NJ 08850 (A.P., R.S.B., J.B.), and Bayer Consumer Care, 36 Columbia Road, Morristown, NJ 07960 (G.S., S.G., A.M.S.). Accepted for publication May 20, 2003. Synopsis Antiseptic-anesthetic first aid formulations typically produce a burning or stinging sensation when used on wounds. The aim of this study was to assess the lack of sting/burn potential of a prototype first-aid wipe when applied to superficial wounds. This was a one-day, double-blind, randomized study, evaluating the stinging/burning sensation from a prototype first-aid wipe with a cellulose base containing 1.0% pramoxine HCL and 0.13% benzalkonium chloride. The study followed a direct comparison test design of four test formulations. The remaining three articles were: (a) sterile 0.9% sodium chloride (no-sting/no-burn control), (b) 3% hydrogen peroxide (first-aid sting/bum control), and (c) 70% isopropyl alcohol (second sting/burn control). The test was performed on 24 subjects. The tape stripping method was used to create four standardized wounds on the volar forearms, reaching the glistening layer. Each test article was applied to the wound for 15 seconds. The subjects were asked to report the intensity of the stinging/burning sensation during the application. The prototype pramoxine-benzalkonium chloride wipe produced significantly less stinging/burning than both 70% isopropyl alcohol and 3% hydrogen peroxide. Also, the prototype wipe did not produce more stinging and burning in superficial wounds compared to the saline control. INTRODUCTION Antiseptic-anesthetic first-aid formulations are used on minor cuts, scrapes, and burns to alleviate or relieve the pain associated with minor wounds and to help prevent skin infections (1). These formulations often produce an immediate burning or stinging sensation of various intensity. Since such products are often used for minor scrapes in children, the development of a formulation that would not sting or burn at first contact is highly desirable. The aim of this investigation was to assess the potential of burning and stinging from a new prototype first-aid wipe formulation on superficial wounds. To control variability in the assessment of sensory responses we used a reproducible and standardized tape- 157

158 JOURNAL OF COSMETIC SCIENCE stripped wound model. Tape stripping using various types of adhesive tapes has been used in the literature to remove the stratum corneum at different depths (2-6). The degree of stratum corneum damage after stripping has often been determined using transepidermal water loss (TEWL) measurements (3,6,7). We adapted the wound model from Bashir et al. (7), where the authors used 40 strippings of Transpore® tape to disrupt the stratum corneum barrier. MATERIALS AND METHODS This was a one-day, double-blind, randomized study evaluating a first-aid wipe formu­ lation for sting/burn potential on induced superficial wounds. The study followed a direct comparison test design of four test formulations. The clinical investigation was approved by an institutional review board, and the informed consent of the subjects was obtained prior to initiation of the investigation. SUBJECT SELECTION Twenty-four healthy subjects (18 females, six males), aged 19-48 (mean age 34), com­ pleted the study. The population consisted of 22 Caucasians, one Hispanic, and one Asian. The main criteria for exclusion were: (a) allergy to first-aid preparations or to local anesthetics, (b) a tendency toward forming keloids, (c) dark pigmentation, and (d) hairy volar forearms. TAPE-STRIP PREP ARA TI ON Transpore® tape (3M, St. Paul, MN) was used to create superficial wounds (7). Prior to the tape-stripping procedure, the individual tape strips were precut to approximately 7 .0 x 1.5 cm and were then applied to release paper for storage. TEST SITES AND WOUNDING PROCEDURE Four test sites were identified in each subject, two on each volar forearm. Each test site (2 x 3 cm) was mapped on the skin with a permanent marker. The test sites were located at least 5 cm from the wrist, 3 cm from the antecubital fossa, and 3 cm from each other. Transepidermal water loss (TEWL) was measured (g/m2/h) by means of a ServoMed EPl evaporimeter (ServoMed AB, Stockholm, Sweden) under standard environmental con­ ditions (8). TEWL was measured at two timepoints: (a) at baseline prior to wounding and (b) after wounding, to verify skin barrier damage. One probe-covering metal plate was dedicated to each subject. Superficial wounds were created by sequential removal of stratum corneum layers using Transpore® tape. Individual tape strips were placed on the test site within the black marks, rubbed firmly, and removed with a quick stroke. This was repeated in alternate directions until a clear glistening layer was visualized upon removal of the strip or after a total of 40 times (7), whichever came first. Once the glistening layer was reached, or the first 40 strips had been removed, TEWL was measured. The criterion for wound standardization was the achievement of a TEWL value in the range of 30-70 g/m2/h. If