Micro- and nanocapsules containing active principles are widely used for dermal and transdermal applications in cosmetics and pharmaceutical preparations. Recently, the dispersion of microcapsules on fabrics have paved the way to new types of products, named cosmeto-textiles [1]. Such products, combining ease of use of a garment and controlled-release from microcapsules, are ideal candidates for complementary therapy of diseases like psoriasis, which require long-term treatment and dedication to the therapy. Nanoencapsulation of caffeine, menthol and melatonin in PCL is discussed in this work, where two different systems for solvent displacement (the confined-impinging jet mixer and the multi inlet vortex mixer) have been extensively investigated. For each mixer, several process parameters, such as fluid dynamics, type of solvent and polymer-to-drug ratio, have been considered to find the optimal configuration for micro- or nanocapsule formation. In Figure 1, an example of nanoparticles prepared in the same conditions (polymer type and concentration, solvent, mixing conditions) loading different substances in the confined impinging jet mixer is shown. The initial mass ratio (MR) of loading substance and polymer may not be the only or main factor determining final size, as it can be noted that nanocapsule formed by using the triglyceride oil are significantly larger than particles prepared dissolving a solid component
