JOURNAL OF COSMETIC SCIENCE 14 SPF value of 15.2 according to ISO 24444 criteria (6). In study RH02117, the number of valid SPF results obtained was deemed insuffi cient, and it was therefore not possible to determine the SPF label for either test product B or test product C. In study RH02385, the mean SPF value for each of test product D and test product E was lower than the in- tended SPF 15. As a result, both lip balm formulations would have been labelled as low sun protection under the ISO 24444 criteria, and labelled SPF 12 and SPF 11, respectively, under the FDA criteria. A key strength of the SPF studies that we conducted is that the methodology we used to determine SPF follows industry standards and protocols as defi ned by the relevant regula- tors [FDA monograph fi nal rule and international standard ISO 24444 (5,6)]. CONCLUSION A new range of lip balm formulations was developed to provide sun protection and mois- turizing abilities. A dry-skin leg model was used to assess the potential moisturizing abilities of one of the new lip balm formulations. Using this model, the test product demonstrated improved leg skin hydration and barrier function properties compared with untreated dry skin, and com- pared with commercially available comparator products. Further testing is required to confi rm these benefi ts on dry lip skin. Data from an exploratory study that used a novel dry-lip hydration model, combining four different assessment methodologies, proved un- reliable. Therefore, further investigation of the lip-hydrating potential of the lip balm formulation is needed. The lip balm formulations studied herein were all rigorously tested to determine their SPF label according to protocols defi ned by relevant regulatory authorities [FDA monograph fi nal rule and international standard ISO 24444 (5,6)]. The SPF values of the tested lip balm formulations did not achieve the intended SPF levels. As such, they will undergo reformulation and retesting to satisfy the required SPF levels. ACKNOWLEDGMENTS The authors would like to thank the participants in these fi ve studies. Editorial support in the form of the development of a draft manuscript in consultation with the authors, and preparation of tables and fi gures was provided by Victoria Pugh, PhD, of Gardiner-Caldwell Communications, Macclesfi eld, UK. FUNDING These studies were funded by GSK Consumer Healthcare (GSK studies RH01927, RH01928, RH02116, RH02117, and RH02385). DISCLOSURES C. Gfeller, G. Hardie, G. Shanga, and H. Mahalingam are all employees of GSK Consumer Healthcare. No additional disclosures to declare.

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