A dispersion including a plurality of bodies dispersed in a continuous phase. Each dispersed body including an internal drop formed with an internal phase miscible with the continuous phase, the internal drop (16) receiving an active product. Each dispersed body including, around the internal drop, a membrane formed with an intermediate phase immiscible with the continuous phase and totally surrounding the internal drop. The ratio R1 of the average thickness (e) of the membrane over the average transverse dimension (Dc) of the active volume delimited by the internal drop and the membrane is greater than 0.05, and is advantageously less than 0.5. The ratio R2 of the partition coefficient of the active product between the intermediate phase forming the membrane and the internal phase forming the internal drop over the viscosity of the membrane is less than 1 s−1·Pa−1.