Hydrolytic degradation of poly(lactide-co-glycolide) films: effect of oligomers on degradation rate and crystallinity

Schliecker, Gesine; Schmidt, Carsten; Fuchs, Stefan; Wombacher, Ralf; Kissel, Thomas

doi:10.1016/s0378-5173(03)00379-x

Cited by 127 publications

(92 citation statements)

References 28 publications

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“…Through the first week the chromatograms look alike and there is no significant change in the elution time of the sample. A slight increase in the molecular weight could be noticed due to the dissolution of small oligomers into the buffer solution [28]. After three weeks of exposure to buffer, the chromatogram peak slowly moves to longer elution times.…”

Section: Gpc Analysismentioning

confidence: 98%

New Biocompatible Polyesters Derived from α-Amino Acids: Hydrolytic Degradation Behavior

2010

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New polymers were synthesized from α-hydroxy acids derived from the natural amino acids Ile, Leu, Phe, and Val, combined with lactic acid, glycolic acid and 6-hydroxyhexanoic acid by direct condensation. The toxicity was determined and the degradation process of these polyesters was investigated under physiological conditions by analyzing the composition of the degraded polymers and the oligomers cleaved in the buffer medium. The polymers were found to be non toxic to two cell lines. Polymers displayed a biphasic degradation behavior. In most cases, a linear relationship was found between the weight loss constant and the hydrophobicity of the polymers, Log P. Regarding the second stage of weight loss, it is apparent that polymers derived from α-hydroxy(L)isoleucine ((L)HOIle) and α-hydroxy(L)Valine ((L)HOVal) degraded much faster than those derived from α-hydroxy(L)leucine ((L)HOLeu) and α-hydroxy(L)phenylalanine ((L)HOPhe), probably due to different spatial orientation of the side chains. Copolymers of 6-hydroxyhexanoic acid displayed slow degradation rates as expected, whereas the degradation profile of copolymers of lactic acid was similar to the other homopolymers. These new polyesters may serve as potential biocompatible materials for medical applications.

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Section: Gpc Analysismentioning

confidence: 98%

New Biocompatible Polyesters Derived from α-Amino Acids: Hydrolytic Degradation Behavior

2010

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“…The quantity and the size of pores have been observed to increase for PLGA-based implantable devices over prolonged periods in vivo (Schliecker et al 2003). The surface morphology of the 10 wt% PLGA particles was studied over 30 days.…”

Section: In Vitro Releasementioning

confidence: 99%

One-step electrohydrodynamic production of drug-loaded micro- and nanoparticles

Enayati

Ahmad

Stride

et al. 2009

J. R. Soc. Interface.

100

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The objective of this work was to produce drug-loaded nanometre-and micrometre-scale particles using a single-step process that provides control over particle size and size distribution. Co-axial electrohydrodynamic processing was used, at ambient temperature and pressure, with poly(lactic-co-glycolic acid) as the polymeric coating material and oestradiol as the encapsulated drug. The particle diameter was varied from less than 120 nm to a few micrometres, by simple methodical adjustments in the processing parameters ( polymer concentration and applied voltage). In vitro studies were performed to determine the drug release profile from the particles during unassisted and ultrasound-stimulated degradation in simulated body fluid. An encapsulation efficiency of approximately 70% was achieved and release of the drug was sustained for a period of over 20 days. Exposing the particles to ultrasound (22.5 kHz) increased the rate of release by approximately 8 per cent. This processing method offers several advantages over conventional emulsification techniques for the preparation of drug-loaded particles. Most significantly, process efficiency and the drug's functionality are preserved, as complex multistep processing involving harsh solvents, other additives and elevated temperatures or pressures are avoided. Production rates of 10 12 particles min 21 can be achieved with a single pair of co-axial needles and the process is amenable to being scaled up by using multiple sets.

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“…6,7 In general, PLGA can degrade into water soluble, non-toxic products of normal metabolism through hydrolysis which is important for its practical application. 8 Moreover, PLGA is one of the few synthetic polymers which have been approved for human clinical use. Several products such as Lupron Depot based on PLGA microparticles are available on the market.…”

Section: Introductionmentioning

confidence: 99%

“…20,21 Previous studies indicate that the formulated IBU microspheres have a high initial burst resulting from the accumulation of drug crystals on the surface of microspheres. 8,22 In some cases, the formulated IBU microspheres are unsuitable for well controlled release.…”

Section: Introductionmentioning

confidence: 99%

Ibuprofen-loaded poly(lactic-co-glycolic acid) films for controlled drug release

Luan¹

2011

IJN

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Ibuprofen- (IBU) loaded biocompatible poly(lactic-co-glycolic acid) (PLGA) films were prepared by spreading polymer/ibuprofen solution on the nonsolvent surface. By controlling the weight ratio of drug and polymer, different drug loading polymer films can be obtained. The synthesized ibuprofen-loaded PLGA films were characterized with scanning electron microscopy, powder X-ray diffraction, and differential scanning calorimetry. The drug release behavior of the as-prepared IBU-loaded PLGA films was studied to reveal their potential application in drug delivery systems. The results show the feasibility of the as-obtained films for controlling drug release. Furthermore, the drug release rate of the film could be controlled by the drug loading content and the release medium. The development of a biodegradable ibuprofen system, based on films, should be of great interest in drug delivery systems.

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Hydrolytic degradation of poly(lactide-co-glycolide) films: effect of oligomers on degradation rate and crystallinity

Cited by 127 publications

References 28 publications

New Biocompatible Polyesters Derived from α-Amino Acids: Hydrolytic Degradation Behavior

New Biocompatible Polyesters Derived from α-Amino Acids: Hydrolytic Degradation Behavior

One-step electrohydrodynamic production of drug-loaded micro- and nanoparticles

Ibuprofen-loaded poly(lactic-co-glycolic acid) films for controlled drug release

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