ABSTRACT
The increasing basic knowledge of the chemistry and biochemistry of cellular and body functions combined with an expanding analysis of the engineering operation of body parts to an explosion of research into three areas. These include prosthetic devices, polymeric drugs, and drug carriers and devices for the controlled release of drugs. Certain drugs, such as the prostaglandins, are rapidly metabolized to inactive compounds and effectively eliminated from the body. Conventional hydrophobic polymers, as rate controlling membranes or matrices, often will not provide a high enough release rate for short-term applications — particularly when water-soluble drugs are being used. With drugs which are very poorly water soluble, the external medium in contact with the polymer phase may become saturated with drug and the release from the device is effectively stopped until drug has diffused out of the unstirred boundary layer. Polymeric inserts and implants can provide both prolonged release and a localized release of a drug at a particular site.
