Systems and methods for generating a film suitable for medical packaging are provided. The film is generated by blown film co-extrusion to form a multi-layer film which has a heat resistant layer, a barrier layer and a heat seal layer. The barrier layer includes a high barrier resin and a branched co-polymer. The high barrier resin has a density of at least 0.963 g/cm.sup.3. The barrier layer includes between 25% and 85% high barrier resin. In some embodiments, an additional laminate layer may be affixed to the heat resistant layer of the multi-layer film. The final film is between 3.0 and 3.8 mils in thickness, and has a moisture vapor transmission rate of less than 0.08.

Provided is an extrusion molding apparatus capable of producing a multi tube with which an outer shape of a cross section is close to a perfect circle. The multi-lumen tube extrusion molding apparatus includes a resin supplying portion, a die that has an extrusion port at a lower end portion and molds the multi-lumen tube as the resin supplied from the resin supplying portion is extruded vertically downward, and an outer surface molding apparatus that molds an outer surface of the extruded tube. In a state in which the resin is supplied from the resin supplying portion to the die, the outer surface molding apparatus depressurizes a molding space of circular cylindrical shape in a state in which the extruded tube is contained in the molding space to mold an outer surface of the contained multi-lumen tube to a circular cylindrical shape.