A barrier adapted to be positioned between a first surface provided in the form of a polymeric, bioactive agent-containing coating upon a medical device, and a second surface provided by another material positioned in apposition, and preferably moveable apposition, to the first surface. The barrier, as provided by block copolymers or photoderivatized polymers, provides protection to the polymeric composition from mechanical damage and/or delamination during fabrication, storage, delivery or deployment, and/or residence of the device within the body. A combination that includes a medical device, such as a stent, and another device, such as a surrounding sheath or internal expandable balloon, between which is positioned a barrier of the type described.