title: Influence of different parameters on droplet size and size distribution of sprayable sunscreen emulsions with high concentration of UV-filters.
abstract: The purpose of this study was to evaluate the possible influence of different formulation and technological parameters such as sunscreen type and concentration, viscosity, propellant gas, actuator and valve type on size and size distribution of droplets in emulsions of waterproof sunscreens conditioned in aerosol cans. Different kinds of emulsion, W/Si and W/O, were prepared with high concentrations of organic and inorganic UV-filters. These formulations were incorporated in aerosol cans with gas (a blend of butane, propane and isobutane). The size and size distribution of the droplets were analysed by laser diffraction using a Malvern Spraytec. The results showed that the sprayability of the formulation and the particle size characteristics of the emitted sprays are dependent on the physicochemical properties of the formulations. Sprayable waterproof sunscreen emulsions, with a high sun protection factor and negligible percentage of emitted droplets below 30 mum, were successfully developed by optimizing formulation parameters and using appropriate actuators and valves.
authors.affiliation: Laboratory of Pharmaceutics and Biopharmaceutics, Université Libre de Bruxelles, Brussels, Belgium.
authors.forename: L
authors.initials: L
authors.lastname: Durand
authors.forename: N
authors.initials: N
authors.lastname: Habran
authors.forename: C
authors.initials: C
authors.lastname: Denis
authors.forename: L
authors.initials: L
authors.lastname: Meulders
authors.forename: V
authors.initials: V
authors.lastname: Henschel
authors.forename: K
authors.initials: K
authors.lastname: Amighi