Abstract: The invention relates to an autonomous portable device for the storage of at least two formulations and for the automatic extemporaneous preparation of an active solution from the two formulations, said device comprising: a first compartment for containment of a first formulation, a second compartment for containment of a second formulation, a retaining chamber which communicates at least with the first compartment by means of at least one transfer channel and which comprises at least one outlet channel for the active solution, manually triggered mixing and expelling means suitable for, after triggering, automatically: bringing the two formulations into contact, and expelling, via the outlet channel, at least a part of the active solution at the end of a minimum reaction time.