title: Chemico-physical and functional properties of inorganic sunscreens in cosmetic products.
abstract: Synopsis This paper reports preliminary results of a study carried out on liquid crystal emulsions added to three different inorganic sunscreens: ultrafine zinc oxide, ultrafine titanium dioxide (inorganic-treated) and ultrafine titanium dioxide (organic-treated hydrophobically). The aim of the work was to investigate the influence of chemico-physical properties of inorganic sunscreens on the microstructure of cosmetic emulsions. The study was carried out using three different techniques: rheological measurements performed in dynamic conditions, to study the homogeneity of samples and their structural features; dispersion of powders in emulsions by optical microscopy and SEM/EDX analysis; and functionality of emulsions by UV spectroscopy, with adhesive tape as substrate. Results show that the different chemico-physical properties of the micropigments lead to different interactions with emulsion components; these interactions may affect the functionality and microstructure of the whole system, with loss of stability.
authors.affiliation: Centro di Cosmetologia Chimica dell'Università di Padova, Dipartimento di Scienze, Farmaceutiche, Via Marzolo 5, 35131 Padova, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Semenzato
authors.forename: C
authors.initials: C
authors.lastname: Dall'aglio
authors.forename: G M
authors.initials: GM
authors.lastname: Boscarini
authors.forename: A
authors.initials: A
authors.lastname: Ongaro
authors.forename: A
authors.initials: A
authors.lastname: Bettero
authors.forename: M E
authors.initials: ME
authors.lastname: Sangalli
authors.forename: F
authors.initials: F
authors.lastname: Brunetta