Hydrolysis studies, controlled release

The rate of biodegradation is thus very complex and depends not only on environmental factors but on the physical characteristics of the polymer artifact, making the overall process difficult to control. Academic and industrial studies are in progress in many laboratories in Europe, USA and Japan to control-hydrolysis more eflfectively both for biomedical devices and for controlled release applications in the body. 

E. Schacht, V. Toncheva, K. Vandertaelen, J. Heller, Polyacetal and poly(ortho ester)-poly(ethylene glycol) graft copolymer thermogels preparation, hydrolysis and FITC-BSA release studies, J. Control. Release 116 (2006) 219-225. 

Studies by our group have established that most metal-containing polymers undergo hydrolysis when wetted. Polymeric derivatives of cis-DDP in DMSO solution also undergo hydrolysis when added to water. Thus, polymeric derivatives of cis-DDP can act as controlled release agents, releasing therapeutic quantities of the active drug. 

The effects of a series of added tertiary amines on the rate of chedn scission of other polyesters, including poly( e-caprolactone-co-lactic acid), has been studied and found to be equally great (65). The mechanism with tertiary amines can only be general base catalysis for the effectiveness of the amines was not related to their pK values or lipophilicities. The acceleration of the hydrolysis of the polyesters was used as a strategy for controlling the drug release rate. 

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