Controlled delivery of therapeutics from microporous membranes. II. In vitro degradation and release of heparin-loaded poly(d,l-lactide-co-glycolide)

Release mechanisms from gentamicin loaded poly(lactic-co-glycolic acid) (PLGA) microparticles

“…The hydrolytic reduction of the polymer molecular weight has not only been shown to be critical for the breakdown of poly(α‐hydroxy acid) microparticles due to increased hydrophilicity of the fragments but also leads to a decrease of the T g 23. Mobility of compounds in polymeric matrices increases drastically as the T g is exceeded, and diffusivity of both penetrating water and escaping drug are higher in the rubbery state 24.…”

Ring-opening precipitation polymerization of poly(D,L-lactide-co-glycolide) in supercritical carbon dioxide

“…1 (c) the product has carbonyl (1 760 cm -1 ), ester (between 1 000 and 1 300 cm -1 ), and methyl functional groups (2 850 cm -1 , associated with lactide) as expected for PLGA. In addition absorption peaks appear at 1 456 cm -1 , 1 423 cm -1 , and 1 382 cm -1 which have been attributed to lactide-lactide, glycolide-glycolide, and lactideglycolide bonding within the PLGA polymer chain 17) . Analysis of the material extracted from the reactor following polymerization (Fig.…”

Low molecular weight heparins for current and future uses: approaches for micro- and nano-particulate delivery

“…Heparins' structure and stability has been the central core of many studies to find suitable drug delivery systems for their administration (Scala-Bertola et al, 2009). The drug load and release profiles obtained from studies on poly-lactic-co-glycolic acid polymer (PLGA)-based microspheres and nanoparticles (NPs) were not encouraging (Kreitz et al, 1997;Jiao et al, 2001;Hoffart et al, 2003Hoffart et al, , 2006 motivating other researchers to prepare microspheres with more satisfactory results (Rawat et al, 2008).…”