A multilayer plastic container for storing lyophilized products includes at least three layers consisting of inner and outer layers having a moisture vapor transmission rate of not more than 0.1 gm mil/100 sq. in.-day at 73° F. and 95% rh, and an intermediate layer of hygroscopic resin construction having a moisture content less than 1000 ppm. The hygroscopic intermediate layer preferably comprises at least 30% of the total thickness of the three layers. The inner and outer layers preferably are of cyclic olefin polymer or cyclic olefin copolymer construction, and the hygroscopic intermediate layer preferably is of amorphous nylon construction. The container preferably is empty and sealed within a secondary container, such as a metallized bag, that is impervious to moisture.
