Multiple layer polymeric structure

The present invention provides a receptacle for a therapeutic fluid susceptible to deterioration on exposure to a gas such as oxygen or carbon dioxide. The receptacle has walls of sheet material each including at least one layer forming a barrier essentially impermeable to such gas, and a seal sealing the walls together in a region thereof. A transfer tube is sealed in the seal having a proximal end in the receptacle, a distal end accessible from outside the receptacle, a flow passage extending between said proximal and distal ends, and a closure blocking flow through the flow passage adapted to be pierced by a tubular needle for transfer of therapeutic through the needle. The transfer tube and closure are essentially impermeable to said gas.