<P> PLGA undergoes hydrolysis in the body to produce the original monomers: lactic acid and glycolic acid . These two monomers under normal physiological conditions, are by - products of various metabolic pathways in the body . Lactic acid is metabolized in the tricarboxylic acid cycle and eliminated via carbon dioxide and water . Glycolic acid is metabolized in the same way, and also excreted through the kidney . Since the body can metabolize the two monomers, there is minimal systemic toxicity associated with using PLGA for biomaterial applications . However, it has been reported that the acidic degradation of PLGA reduces the local pH low enough to create an autocatalytic environment . It has been shown that the pH inside a microsphere can become as acidic as ~ 2.8 . </P> <P> Specific examples of PLGA's use include: </P> <Ul> <Li> A commercially available drug delivery device using PLGA is Lupron Depot for the treatment of advanced prostate cancer . </Li> <Li> prophylactic delivery of the antibiotic vancomycin into the central nervous system when applied to the surface of the brain after brain surgery </Li> </Ul> <Li> A commercially available drug delivery device using PLGA is Lupron Depot for the treatment of advanced prostate cancer . </Li>

Lactic acid and glycolic acid are the monomers used for preparation of polymer