title: Molecular weight distribution changes during degradation and release of PLGA nanoparticles containing epirubicin HCl.
abstract: The molecular dynamics of the degradation process of poly(lactic-co-glycolic acid) nanospheres were investigated during the degradation process usually observed when these polymers are used as controlled release carriers. The molecular weight distribution of PLGA samples was determined over a period of 32 days by accurately analyzing the molecular weight distribution of the polymer as a function of time as degradation progressed. The molecular weight distribution shifted gradually to lower average molecular weights over 32 days, with significantly smaller molecular weight components appearing at 8-12 days. In addition, the degradation of nanospheres containing epirubicin HCI was analyzed and increasing the amount of epirubicin from 1.7 to 3.4 to 6.7 wt% was found to hasten the degradation of the nanoparticles and subsequently affect the release behavior from these particles. This is believed to be the first time that such molecular dynamics have been presented for the degradation of PLGA nanoparticle formulations containing a drug for controlled delivery.
authors.affiliation: Biogel Technology, Inc., 9521 Valparaiso Court, Indianapolis, IN 46268, USA.
authors.forename: Duane T
authors.initials: DT
authors.lastname: Birnbaum
authors.forename: Lisa
authors.initials: L
authors.lastname: Brannon-Peppas
mesh_terms: D001673:Biodegradation, Environmental; D002850:Chromatography, Gel; D003692:Delayed-Action Preparations / Q000737:chemistry* / Q000378:metabolism; D004337:Drug Carriers / Q000737:chemistry* / Q000378:metabolism; D015251:Epirubicin / Q000008:administration & dosage; D007700:Kinetics; D019344:Lactic Acid / Q000737:chemistry* / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy; D008970:Molecular Weight; D036103:Nanotechnology; D010316:Particle Size; D011100:Polyglycolic Acid / Q000737:chemistry* / Q000378:metabolism; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011108:Polymers / Q000737:chemistry* / Q000378:metabolism
chemical_list: D003692:Delayed-Action Preparations; D004337:Drug Carriers; D011108:Polymers; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; D015251:Epirubicin