Composite particles are provided comprising at least one core including at least one organic polymer in which is dispersed at least one hydrophobic active material. The hydrophobic active material is a cosmetic, pharmaceutical, food or plant-protection material. The composite particles also include one external coating including at least one oxide and/or hydroxide of aluminum, of silicon, of zirconium and/or of a transition metal and one intermediate layer, present at least partially between the core and the external coating and including at least one alkaline earth metal hydroxide.