A nanocrystal formulation in the form of a nano-emulsion includes a continuous aqueous phase and at least one dispersed oily phase, in which the oily phase has at least one amphiphilic lipid and at least one solubilising lipid, and in which the aqueous phase has a cosurfactant. The invention also relates to a method for the production of the formulation as well as uses within the fields of medical imaging, thermotherapy or phototherapy.