Oxygen is a double edged sword for all living organisms and a lot of drugs. Although life sustaining but it degrades many biochemical molecules including those that make up human beings. That is why patients are rarely given 100% oxygen. All living organisms have systems to defend against oxidation because of its corrosive effect on the delicate biochemicals which make up their cells. Many drugs are susceptible to degradation by oxidation. Biologically derived drugs are particularly susceptible. As a result a lot of care is taken in creating these types of drugs in a nonixidative environment. Drugs using water solution as a diluent typically get stored in glass bottles, or polymer bags. Sometimes the liquid storage problem is bypassed and drugs get mixed just before delivery.
The most effective way to keep oxygen out of a container is to line it with aluminum or create it from a a multilayer polymer film with aluminum foil as one of the layers. However transparency is typically required for medical purposes. A research in lab at the Department of Chemical Engineering, Texas A&M University has announced a technology that is completely polymer based and may be able to act as a substitute for current film laminates. Time will tell.