Device for packaging and dispensing a product, notably a pharmaceutical or cosmetic product

A device for packaging and dispensing a product, notably a pharmaceutical or cosmetic product, comprising a storage container provided with at least one variable-volume compartment containing said product, a pressurizing means that is able to permanently pressurize the product contained in said compartment, and a dispensing head comprising a mounting base fastened to the container, wherein the pressurizing means comprises a partition wall and an elastically deformable mechanical member that exerts a permanent pushing force on the partition wall in the direction of the dispensing head, characterized in that the dispensing head also comprises:

• a dispensing member mounted inside the mounting base in a rotatable manner,
• a piston comprising a rod, and a piston head fastened on each end of the rod in an adjustable manner, wherein the piston is movable in translation inside the dispensing member and is able to delimit, inside said member, opposite first and second metering chambers, and
• at least first and second orifices that are formed in the dispensing member and are respectively able to be in direct fluidic communication with the first and second metering chambers,
• the metering member being movable at least between a first position, in which said first orifice is in fluidic communication with the variable-volume compartment of the container and in which said second orifice is in fluidic communication with at least one outlet orifice of the dispensing head, and a second position, in which said second orifice is in fluidic communication with said variable-volume compartment and in which said first orifice is in fluidic communication with said outlet orifice.