ABSTRACT
Synthetic and natural-based polymers have found their way into the pharmaceutical and biomedical industries, and their applications are growing at a fast pace. Major applications of polymers in the current pharmaceutical field are for controlled drug release, which will be discussed in detail in the following sections. In the biomedical area, polymers are generally used as implants and are expected to perform long-term service. In general, the desirable polymer properties in pharmaceutical applications are film forming (coating), thickening (rheology modifier), gelling (controlled release), adhesion (binding), pH-dependent solubility (controlled release), solubility in organic solvents (taste masking), and barrier properties (protection and packaging). From the solubility point of view, pharmaceutical polymers can be classified as water-soluble and water-insoluble (oil soluble or organic soluble). In this entry, many water-soluble biomedical and pharmaceutical polymers including polyethylene glycol (PEG), polyvinyl alcohol, polyethylene oxide, polyvinyl pyrrolidone, polyacrylate or polymethacrylate esters, cellulose-based polymers, hydrocolloids, and many plastics and rubbers will be tabulated and their anionic and cationic functionalities will be summarized and discussed. This entry will also focus on PEGylation, defined as the covalent attachment of PEG chains to bioactive substances.
