268 JOURNAL OF COSMETIC SCIENCE epidermal properties after 1 month and both epidermal and dermal properties after 3 months. The control group showed modest improvements in surface properties only. These results demonstrate that significant appearance benefits can be derived from use of exfoliative proteolytic enzymes. Such improvements are the result of changes to the epidermis and dermis and are strikingly similar to results observed with higher concentrations of AHAs (alpha hydroxy acid ). Protection Against Singlet Oxygen, The Main Actor of Sebum Squalene Peroxidation During Sun Exposure, Using Commiphora Myrrha Essential Oil B. Auffray Application and Development Laboratory, Robertet, 37, Avenue Sidi Brahim-B.P. 52100-06131 Grasse Cedex, France Squalene is a component of sebum. Both are directly exposed to the external environment and play a key role in sktn physiology. They are particularly prone to photo oxidation during sun exposure. We studied the impact of two types of antioxidant on sebum squalene peroxidation by UV irradiation. The first type is free radical scavenger (Butyl hydroxyl toluene and an olive extract rich in hydroxytyrosol). The second type is the essential oil of Commipora myrrha, a singlet oxygen quencher. These properties were confirmed using the 2,2-diphenyl-1- picrylhydrazyl test for antiradical capacity [Yoshida et al. (1989) Chem. Pharm. Bult., 37, 1919 Buenger et al. (2006) Int J. Cosmet. Sci., 28, 135] and 1,3- diphenylisobenzofuran test for the capacity to quench singlet oxygen [Kochewar and Redmond (2000) Meth. Enzymol., 28, 319 Racine and Auffray (2005) Fitoterapia, 76, 316]. Furthermore, we have extended an ex vivo method to classify the efficacy of cosmetics to protect squalene by collecting sebum in vivo and irradiating it in a controlled way. The squalene monohydroperoxide formation is monitored by high performance liquid chromatography. This methods allows us to compare the efficiency of the three antioxidants at 0.6% in a cosmetic formulation to protect squalene from photo oxidation. Our results clearly show that essential oil of Commiphora myrrha provides the best protection against squalene peroxidation. These results demonstrate that squalene peroxidation during solar exposure is mainly because of singlet oxygen and not due to free radical attack. This suggests that sun care cosmetics should make use not only of free radical scavengers but also of singlet oxygen quenchers. Impact of Shaving and Anti-Perspirant Use on The Axillary Vault G. A Turner"', A. E. Mooret, V. P . .T. Marti"', S. E. Paterson"' and A G. Jamest "'Unilever Research & Development Port Sunlight, Quarry Road East, Bebington, Merseyside CH63 3JW, U.K. and tUnilever Colworth, Colworth House, Shambrook, Bedford MK44 lLQ, U.K Shaving the axilla is a regular part of the personal care regime for many women in Europe, North and South America. To assess the impact of shaving on underarm skin, a series of investigations were carried out, in which the thickness of the axillary vault and fossa were measured using optical coherence tomography (OCT), and underarm shaving debris was collected for study. The response of the axilla to histamine iontophoresis was also investigated. Additionally, a study was carried out to investigate the impact of a novel anti-perspirant roll-on formulation on irritation and self-perceived sensory properties of the axilla. The results clearly demonstrate that shaving the underarm consistently removes skin (stratum comeum) as well as axillary hair ( with a mean value of 36.1 % of the debris being skin). OCT measurements demonstrated that in shaved areas of the axilla, epidermal thickness is higher than in unshaved areas. In response to histamine, wheal and flare were both found to be greater in the shaved axilla, when compared with an unshaved control, but flare in the fossa was greater than that in the vault. On the basis of these results, we propose that the axillary vault has adapted to frequent shaving, notably by the development of a thickened epidermis. However, this adaptation is often not sufficient to fully protect the axilla from damage and irritation resulting from hair removal (shaving). In these instances, we have demonstrated that use of a novel anti­ perspirant roll-on formulation containing glycerol and sunflower seed oil was able to reduce the impact of shaving-induced irritation and improve self-assessment of axillary condition. Nanosystems for Skin Hydration: A Comparative Study E. Esposito"', M. Drechslert, P. Marianit, E. Sivieri"', R. Bozzini§, L. Montesi§, E. Menegatti"' and R. Cortesi"' "'Department of Pharmaceutical Sciences, University of Ferrara, 1-44100 Ferrara, Italy, tMacromolecular Chemistry II, University of Bayreuth, Bayreuth, Germany, tDipartimento di Scienze Applicate ai Sistemi Complessi e INFM, Universita Politecnica delle Marche, Ancona, Italy and §Center of Cosmetology, University of Ferrara, 1- 44100 Ferrara, Italy The present investigation describes a comparative study for the design of innovative topical formulation for skin hydration. In particular, different colloidal forms based on lipidic components have been produced and characterized. Morphology and dimensional distribution have been investigated by means of electron microscopy and photon correlation spectroscopy. Nanoparticulate systems characterized by different morphology and dimensions depending on production procedures have been obtained, namely cubosomes, nanovesicles, solid lipid nanoparticles and liposomes. Hydration power has been studied by means of a comeometer, measuring the skin electrical capacitance before and after the application of opportunely viscosized nanoparticulate systems. It has been demonstrated that nanovesicle gel displayed a pronounced hydration power with respect to the other nanostructured forms, it'I hydration effect on skin was 3.5-fold higher, with respect to the untreated area, after 5 min from the application and 1.5- fold higher after 2 h. Study of Dyeing Properties of Semipermanent Dyestuffs for Hair B. Ballarin•, S. Galli• and M. Morigit "'Department of Physical and Inorganic Chemistry, Universita di Bologna, V.le Risorgimento, 4 40136 Bologna, and tllios snc, v.L. Basso 170, 47023 Cesena, Italy In this article we have evaluated some of the factors (pH, solvent composition and dye structure) that influence the dyeing of hair with dyes from direct semipermanent categories. These dyes, in fact, have been used more and more in cosmetic industry over the last years, due to their lesser aggressiveness vs. hair fibres. Two different dye classes are investigated: phenylene diamine (HC), well known for their low molecular weight and their small size, and a series of Basic dyes, characterized by the same ionic charge (positive) but with different sizes and different polar groups in the molecule. pH and dyebath composition result critical factors controlling the diffusion and adsorption