Compatibility test is to confirm the packaging and medicine don’t react and thus damage during contacting. The time compatibility test is very long. It is at least a few month, and even one of a few years. The compatibility test will be performed by the manufacturer of finished medicine instead of the manufacturer of packaging. The manufacturer of packaging only provide the basic certificates for food safety.
One point must be clear is compatibility refers to the damage of packaging or medicine or both doesn’t exceed the limit in the standard after they contact for the whole shelf time. For packaging, that is long time contacting materials, the contacting time is 2 to 3 years normally. For device, that is shot tiem contacting materials such as syringe and needle, the contacting time is even a few minutes.
Generally, a packaging material with good chemical resistance has better compatiblity with medicine. However, it is not the full concerned points of compatibility. Compatibility also includes the damage of the medicine. For example, although the packaging doesn’t damage, the concentration or the ratio of the mixed ingredient composition changes. The compatibility test is also failed.