Class Of Biodegradable Polymers Research Articles

Controlled Drug Delivery by Biodegradable Poly(Ester) Devices: Different Preparative Approaches

There has been extensive research on drug delivery by biodegradable polymeric devices since bioresorbable surgical sutures entered the market two decades ago. Among the different classes of biodegradable polymers, the thermoplastic aliphatic poly (esters) such as poly(lactide) (PLA), poly(glycolide) (PGA), and especially the copolymer oflactide and glycolide referred to as poly(lactide-co-glycolide) (PLGA) have generated tremendous interest because of their excellent biocompatibility, biodegradability, and mechanical strength. They are easy to formulate into various devices for carrying a variety of drug classes such as vaccines, peptides, proteins, and micromolecules. Most importantly, they have been approved by the United States Food and Drug Administration (FDA) for drug delivery. This review presents different preparation techniques of various drug-loaded PLGA devices, with special emphasis on preparing microparticles. Certain issues about other related biodegradable polyesters are discussed.

Erosion of poly(anhydride-co-imides): A preliminary mechanistic study

A new class of biodegradable polymers that show promising characteristics for orthopedic applications was investigated. This study examines aspects underlying the polymer erosion of poly[trimellitylimidoglycine-co-1,6-bis(carboxyphenoxy)hexane] and poly[pyromellitylimidoalanine-co-1,6-bis(carboxyphenoxy)hexane].Copolymer degradation was studied by examining the anhydride bond hydrolysis and copolymer composition by IR and NMR spectroscopy. Hydrolysis of the anhydride bonds occurred much faster than did the dissolution of the hydrolyzed products, leading to the formation of two distinct erosion zones. The two erosion zones were observed by light and scanning electron microscopy with erosion originating at the surface and moving to the center of the polymer samples. © 1996 John Wiley & Sons, Inc.

Controlled release from poly(phosphoester) matrices

A class of biodegradable polymers, poly (phosphoesters), was studied for its potential as a matrix for controlled drug delivery. The degradability of the phosphorus ester linkage and the versatility of phosphorus-containing polymers make poly (phosphoesters) attractive candidates for development as a degradable biomaterial. The release of various drugs in vitro from a series of bisphenol-A based poly (phosphoesters) was examined. Sustained release for up to several months was achieved for cortisone acetate and model drug p-nitroaniline. The mechanism of release was found to be a combination of diffusion, swelling and degradation. The structure of the sidechain influenced the release behavior in all instances.