Abstract: The present invention is directed to an automatic injection device containing a pre-loaded charge of medicament for automatically self-administering the medicament upon actuation thereof. The automatic injection device includes a housing assembly having an interior chamber, a filter assembly, an activation assembly and a needle assembly. In accordance with the present invention, the interior chamber may include a dry compartment for storing a predetermined dry charge of dry medicament therein, and a wet compartment for storing a predetermined amount of liquid injection solution therein. The filter assembly enhances the laminar flow of fluid between the wet compartment to the dry compartment prior to the pressurization of the liquid injection solution within the wet compartment.