J. Cosmet. Sci., 69, 1–8 ( January/February 2018) 1 A Prototype Lip Balm: Summary of Three Dermatological Studies Demonstrating Safety and Acceptability for Sensitive Skin STEPHANIE NISBET, GlaxoSmithKline Consumer Healthcare, Weybridge, Surrey, United Kingdom Accepted for publication November 2, 2017. Synopsis Data were generated from three studies to assess the tolerability and acceptability of a prototype cosmetic lip balm. Dermatological assessments of topical compatibility (primary and cumulative irritability and sensitization), photoirritant and topical photosensitizer potential, and acceptability for safe use of a prototype cosmetic lip balm on sensitive skin are summarized. In Study 1, the product was applied to the volunteers’ backs under a semiocclusive patch followed by patch removal/reapplication over 6 weeks to assess the irritant and allergic potential of the product. Dermatological assessments were performed at the beginning and end of the study or when there was evidence of positivity or adverse event. Study 2 was conducted by applying the product to the volunteers’ backs under a semiocclusive patch, followed by patch removal/reapplication and irradiation of the test area with ultraviolet A (UVA) radiation at various intervals over 5 weeks. Dermatological assessments were performed to assess the product’s role in the induction of photoirritancy and photosensitization. Clinical and subjective assessments for acceptability were obtained during Study 3 in volunteers with a diagnosis of sensitive skin and those who used the product as per instructions for use during the study period. The data generated from the three studies demonstrated no evidence of primary or cumulative dermal irritation or of dermal sensitization. In addition, no photoirritation potential or photosensitization potential was observed. As assessed by dermatologic monitoring and subject diary entries, the prototype lip balm did not cause irritation or sensitization reactions when used for 28 days in volunteers with a diagnosis of sensitive skin. Based on these fi ndings, the prototype lip balm can be considered suitable for use for people with sensitive skin. INTRODUCTION Lip balms provide an occlusive layer on the lip surface to seal moisture and to protect the lips from external exposures, such as dry air, cold temperatures, and wind. The skin on the lips is thin which increases the vulnerability to dryness (1). A prototype cosmetic lip balm was developed for use in dry, sensitive skin. To thoroughly assess the safety and risks, and to ensure the appropriate conditions for product use, cosmetic products require clinical testing in humans. Data generated during Address all correspondence to Stephanie Nisbet at stephanie.j.nisbet@gsk.com.

JOURNAL OF COSMETIC SCIENCE 2 clinical studies are also important to defi ne the instructions for use, appropriate site of use, and informative product labeling. Compatibility studies are clinical assessments of the safety of topical products on the human skin. These studies are generally conducted with occlusive or semiocclusive patches (patch tests) or in open models (open tests). These literature-based topical safety protocols consist of repeated applications under maximized conditions, and the absence of adverse reactions indicates that the product is safe for use under the specifi ed test conditions. See Table I. Compatibility evaluations are performed by a dermatologist and results are interpreted using the ICDRG (International Contact Dermatitis Research Group) scale (2). Sensitive skin is generally accepted as a subjective cutaneous hyperreactivity to environ- mental factors, although there is no consensus regarding its etiology, classifi cation, or criteria for diagnosis. Surveys across EU, the US, and Japan estimate that 50% of people believe they have sensitive skin (3,4). Consumer reports of sensitive skin are typically self-diagnosed and appear to be increasing both in women and men. The term sensitive skin has come to be defi ned as an onset of prickling, burning, or tingling sensation because of ultraviolet light, heat, cold, wind, cosmetics, soap, water, pollution, stress, or endogenous hormones (4). One or several of these factors in combination may lead to greater skin irritation caused by a decreased stimulation threshold of nerve endings (hence a higher response to any stimulus), or by decreased epidermal barrier function, therefore a higher index of skin permeation and an increased irritative response and sensation effect. From the dermatological point of view, sensitive skin is a skin condition of greater ir- ritability to external stimuli due to several causes. It is a skin hyper-reactive, regardless of the etiology (5). Several conditions may lead to or contribute to the underlying etiol- ogy of sensitive skin: dermatoses, such as rosacea, seborrheic dermatitis, atopic derma- titis, and contact dermatitis, and specifi c sensitizations (allergy) perpetuating the skin sensitivity. In the development of topical products intended for use in people with sensitive skin, various criteria are critical to consider, including minimizing the number of required Table I Types of Compatibility Studies Study name Methodology Primary and cumulative skin irritation Test product is applied to volunteers in an open-patch, semiocclusive, or occlusive fashion Contact length and timeline for readings are standardized Photoirritation Irradiation is applied at the test product application site, typically on the forearm or on the back Dermal sensitization Test product is applied to volunteers in a semiocclusive or occlusive patch (on the forearm or on the back) Study consists of three phases: Induction, rest, and challenge Photosensitization Test product is applied to volunteers in an occlusive or semiocclusive patch (on the forearm or on the back) Study consists of induction, rest, and challenge phases An ultraviolet light (A-band) is used to irradiate test area