title: Effect of plasticization on heparin release from biodegradable matrices.
abstract: Heparin-loaded polymer films of poly-L-lactide (PLLA) and poly-L-lactide-co-glycolide (PLLGA) as well as poly-DL-lactide-co-glycolide (PLGA) were produced. A plasticizer, PEG, was added to the polymers. It was found that the release profile in general consisted of a burst effect, a diffusion-controlled phase and a degradation-controlled phase. The plasticizer accelerated the onset of degradation in all cases, but its effect on the release profile differed significantly depending on the polymer. The plasticizer depressed the burst effect for PLLA, and accelerated the kinetics of the diffusion-controlled phase. For the PLLGA 80/20, however, the plasticizer had no significant effect on the release profile or kinetics. We explain these observations in terms of hydrophilicity and crystallinity effects.
authors.affiliation: School of Materials Engineering, Nanyang Technological University, N4.1-1-30 Nanyang Avenue, Singapore 639798, Singapore.
authors.forename: L P
authors.initials: LP
authors.lastname: Tan
authors.forename: S S
authors.initials: SS
authors.lastname: Venkatraman
authors.forename: P F
authors.initials: PF
authors.lastname: Sung
authors.forename: X T
authors.initials: XT
authors.lastname: Wang
mesh_terms: D020341:Absorbable Implants; D000925:Anticoagulants / Q000008:administration & dosage*; D001672:Biocompatible Materials; D006493:Heparin / Q000008:administration & dosage*; D019344:Lactic Acid; D010968:Plasticizers; D011091:Polyesters; D011100:Polyglycolic Acid; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011108:Polymers; D015607:Stents; D013678:Technology, Pharmaceutical
chemical_list: D000925:Anticoagulants; D001672:Biocompatible Materials; D010968:Plasticizers; D011091:Polyesters; D011108:Polymers; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; C033616:poly(lactide); D006493:Heparin