Process for obtaining submicronic particles, for example, pigments in the presence of lipidic vesicles having a lamellar structure, starting with at least one precursor of said particles involves preparing a dispersion of vesicles starting with at least one lipid capable of forming the walls of the vesicles and an aqueous phase E intended to be encapsulated in the said vesicles, and optionally an aqueous phase D, intended to form a dispersion medium of the said vesicles, at least one precursor of the said vesicles being dissolved in phase E and/or D, before and/or during and/or after the preparation of the vesicular phase, at least one agent capable of transforming the said precursor(s) into sought after particles being reacted with it (them) after introduction into the preparation medium.