Imaging the porous structure in the core of degrading PLGA microparticles: The effect of molecular weight

Mylonaki, Ioanna; Allémann, Éric; Delié, Florence; Jordan, Olivier

doi:10.1016/j.jconrel.2018.07.044

Cited by 49 publications

(44 citation statements)

References 34 publications

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“…These effects should lead to early degradation in the UP solution. Figure 10 shows areas of the composite where degradation is evident around larger crystal structures after release, which also occurs in poly(lactic-co-glycolic acid) drug delivery systems with autocatalysis reported by Siepmann's group and Mylonaki's group [56,57]. EDS elemental analysis indicates locally higher phosphate concentration in the degraded pore structures.…”

Section: Discussion and Modeling Of Diffusion-degradation Release Behmentioning

confidence: 62%

Degradable Controlled Release Fertilizer Composite Prepared via Extrusion: Fabrication, Characterization, and Release Mechanisms

2020

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In this work, biodegradable polymers were melt compounded with urea phosphate to fabricate “smart fertilizers” for sustainable agriculture. Urea phosphate (UP) is typically applied as a water-soluble fertilizer to treat phosphorus deficiency in high pH soils. Due to the low diffusion rate of phosphate through slow-release fertilizer coatings, phosphate supply has been considered the “bottleneck” for nitrogen–phosphorous–potassium (NPK) nutrients supply. We study the influence of polymer matrix structure on release kinetics in deionized water using novel polyesters including poly (hexamethylene succinate) (PHS), poly (30% butylene succinate-co-70% hexamethylene succinate) (PBHS 30/70), and PBHS 70/30. Melt processed composites of UP and polyester were analyzed to determine UP loading efficiency and dispersion and distribution of the salt in the polymer matrix. A combined empirical model involving diffusion and erosion mechanisms was found have a good agreement with the experimental release curve. This work provides a solution for environmentally friendly controlled release phosphate fertilizer with good release performance using bio-based and biodegradable polymers.

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Section: Discussion and Modeling Of Diffusion-degradation Release Behmentioning

confidence: 62%

Degradable Controlled Release Fertilizer Composite Prepared via Extrusion: Fabrication, Characterization, and Release Mechanisms

2020

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“…The internal structure of the particles, checked in terms of MW, pore formation and T g , is nowadays considered of primary importance in drug kinetics release (Mylonaki et al 2018). On the other hand, considering that drug release is related to drug-polymer interaction, drug characteristics as MW, log-P, concentration also appear to be crucial (Mao et al 2007).…”

Section: In Vitromentioning

confidence: 99%

Recent advances in the formulation of PLGA microparticles for controlled drug delivery

et al. 2020

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Polymeric microparticles (MPs) are recognized as very popular carriers to increase the bioavailability and bio-distribution of both lipophilic and hydrophilic drugs. Among different kinds of polymers, poly-(lactic-co-glycolic acid) (PLGA) is one of the most accepted materials for this purpose, because of its biodegradability (due to the presence of ester linkages that are degraded by hydrolysis in aqueous environments) and safety (PLGA is a Food and Drug Administration (FDA)-approved compound). Moreover, its biodegradability depends on the number of glycolide units present in the structure, indeed, lower glycol content results in an increased degradation time and conversely a higher monomer unit number results in a decreased time. Due to this feature, it is possible to design and fabricate MPs with a programmable and time-controlled drug release. Many approaches and procedures can be used to prepare MPs. The chosen fabrication methodology influences size, stability, entrapment efficiency, and MPs release kinetics. For example, lipophilic drugs as chemotherapeutic agents (doxorubicin), anti-inflammatory non-steroidal (indomethacin), and nutraceuticals (curcumin) were successfully encapsulated in MPs prepared by single emulsion technique, while water-soluble compounds, such as aptamer, peptides and proteins, involved the use of double emulsion systems to provide a hydrophilic compartment and prevent molecular degradation. The purpose of this review is to provide an overview about the preparation and characterization of drug-loaded PLGA MPs obtained by single, double emulsion and microfluidic techniques, and their current applications in the pharmaceutical industry. Graphic abstract

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“…How it affects the release kinetics from PLGA microspheres has yet to be fully elucidated. Siepmann et al (2005) highlighted the importance of the autocatalytic effects in PLGA degradation and drug release kinetics from microparticles and, more recently, Mylonaki et al (2018) called attention to how the accumulation of acidic by-products affects PLGA microparticle porosity (non-homogeneous pore distribution) and internal structure evolution.…”

Section: Figmentioning

confidence: 99%

Poly(lactic acid)/poly(lactic-co-glycolic acid)-based microparticles: an overview

Blasi

2019

J. Pharm. Investig.

168

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Background Poly(glycolic acid), poly(lactic acid) and poly(lactic-co-glycolic acid) were approved by the United States Food and Drug Administration (FDA) in the 1970s as materials for the manufacturing of bioresorbable surgical sutures, but soon became the reference materials for the preparation of sustained release formulations, especially injectable microparticles. Since the 1986 approval of Decapeptyl ® SR, the first product based on PLGA microspheres, more than 15 such products have been approved for clinical use. Area covered This article highlights the key steps that brought to the development of injectable poly(lactic acid)/poly(lacticco-glycolic acid) microparticles for the sustained release of active pharmaceutical ingredients. After a brief history of some pioneering works that opened the field of controlled drug delivery, the key steps that led to the development of these polymers and the approval of the first microparticle-based medicinal products are reviewed. Finally, the general characteristics of these polymers are described and the classical preparation method is explained. Expert opinion Poly(lactic acid)/poly(lactic-co-glycolic acid) microparticles are among the most successful drug delivery systems. The recent approval of new medicinal products based on PLGA microspheres is the proof that pharmaceutical companies have continued to exploit this drug delivery technology. The possible development of generics and the continuous discovery of therapeutic peptides will hopefully further the success of microsphere technology.

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Imaging the porous structure in the core of degrading PLGA microparticles: The effect of molecular weight

Cited by 49 publications

References 34 publications

Degradable Controlled Release Fertilizer Composite Prepared via Extrusion: Fabrication, Characterization, and Release Mechanisms

Degradable Controlled Release Fertilizer Composite Prepared via Extrusion: Fabrication, Characterization, and Release Mechanisms

Recent advances in the formulation of PLGA microparticles for controlled drug delivery

Poly(lactic acid)/poly(lactic-co-glycolic acid)-based microparticles: an overview

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