4. Controlled release of fragrances without microcapsules

It is possible to influence the olfactory profile of a fragrance and its evolution over time by leveraging the interactions between fragrance molecules and the cosmetic base, which often includes polar and nonpolar phases as well as surfactants. These phases typically coexist in the form of oil-in-water (O/W) or water-in-oil (W/O) emulsions, O/W or W/O microemulsions, or lamellar, hexagonal, or cubic mesophases, stabilized by varying amounts of surfactants. The resulting morphologies can be highly diverse, as illustrated in the figure  11