System for preparing a personalized composition using pressure

A preparation and dispensing system for preparing and dispensing a personalized composition from N reserves (501-508) of active compounds (A1-A2), N being an integer greater than or equal to 1, each of the reserves having a hydraulic resistance (Rh2) and each of the reserves comprising a fluid inlet (511-518), a fluid outlet (521-528) and a body (530) comprising at least one active compound, the system comprising a pneumatic-pressure generator (200, 201-202) connected to a pressure distributor (300) comprising N pressure changeover switches (301-306), each N pressure changeover switch having at least one inlet (I1) connected to the pneumatic-pressure generator, one inlet (I2) connected to atmospheric pressure and an outlet (311-316) connected to the fluid inlet of one of the reserves of active compounds (A1-A2), such that each reserve (501-508) of active compound (A1-A2) can be placed in communication either with atmospheric pressure, or with pressure generated by the pneumatic-pressure generator, and in that each of the reserves of active compound comprises, at the fluid outlet of each of the reserves, an ejection nozzle (500), a hydraulic resistance (Rh1) of which is higher than the hydraulic resistance (Rh2) of each of the reserves of active compound, wherein each of the reserves of active compound is made up of an interchangeable multi-dose cartridge (501-508) and of a cartridge support (400) designed to keep, in use, hermetically and independently, each inlet of each interchangeable multi-dose cartridge with each outlet of each of the pressure changeover switches.