ABSTRACT
Many soluble polymers have been proposed for use in therapeutic systems for treatment of a range of diseases (1). Several have undergone exhaustive examination in animals, and a few have made it through to clinical evaluation. The most extensively developed of these is poly(ethylene glycol) (pEG), which is now being used clinically in treatment of several disorders using polymer-protein conjugates and also forms an important excipient in the formulation of many licensed drugs (2-8). There are no significant toxicities associated with pEG, although doses administered parenterally have usually been fairly small. Poly-(vinylpyrrolidone) (pVP) has been evaluated for clinical use as a plasma expander and was administered to several hundreds of soldiers in high doses during the Second World War. pVP does appear to be associated with a storage disease termed ‘‘la maladie vinylique,’’ but the frequency of this is remarkably low and, considering the doses administered and the delay to onset, the overall toxicity profile is very mild (9-12). Copolymers based on poly [N-(2-hydroxypropyl)methacrylamide] (pHPMA) have also seen clinical application in recent years (see below) and there have been no reported instances of any polymerrelated toxicities in over 50 cancer patients treated.
