Microsphere refers to a spherical microparticle between 1 and 1,000 microns (μm) in diameter (see Figure 1). Also known as spheres, balls, beads or micro-balloons, microspheres are manufactured from a variety of raw materials. The most common types are solid and hollow glass or polymer microspheres, as well as ceramic. Each type is designed in different grades depending on the application and quality requirements. The quality of the microspheres ranges from monodispersed microspheres produced under tight specifications, to microsphere grades with variations in particle size and sphere uniformity.
Glass, polymer and ceramic microspheres are well-known in the cosmetics and personal care industry for advantages such as sensorial benefits and optical effects, among others.1 Their spherical shape and smooth surface create a low friction ball-bearing effect that gives formulations an elegant, silky feel. This ball-bearing effect promotes better blending on the skin and a more natural finish due to the enhanced slip, glide and omnidirectional spreadability, imparting a cream to powder texture. Outstanding roundness also provides lubrication during application, which enhances the tactile experience of a cosmetic product.