A protocol for assay of poly(lactide- co -glycolide) in clinical products

Garner, John; Skidmore, Sarah; Park, Haesun; Park, Kinam; Choi, Stephanie; Wang, Yan

doi:10.1016/j.ijpharm.2015.08.063

Cited by 51 publications

(33 citation statements)

References 21 publications

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“…The block copolymers were synthesized following the procedure described previously with the modification that PEG‐diol was utilized as the initiator . Prior to synthesis, all glassware was washed in acetone and dried at 100 °C followed by cooling in a desiccator.…”

Section: Methodsmentioning

confidence: 99%

“…Gel permeation chromatography–external standard (GPC–ES) was performed according to methods described previously . Briefly, samples were dissolved at a concentration of 2 mg/mL in either DCM or THF and 0.22 μm filtered prior to analysis.…”

Section: Methodsmentioning

confidence: 99%

“…Briefly, samples were dissolved at a concentration of 2 mg/mL in either DCM or THF and 0.22 μm filtered prior to analysis. GPC was performed using either a Waters Breeze 2 system operated by Empower software with an RI detector with 1 mL/min THF across a minimum of three sequential columns (two or three Phenogel 5 μm (300 × 7.8 mm) and one Resipore 3 μm (Agilent)) or using the previously described Varian Prostar system in DCM mobile phase with UV–vis detection . The system was calibrated using polystyrene standards (Agilent PS2 standards) and this calibration was used to obtain the number average molecular weight ( M n ), the weight average molecular weight ( M w ), and the polydispersity index (PDI).…”

Section: Methodsmentioning

confidence: 99%

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Narrow molecular weight margins for the thermogelling property of polyester–polyether block copolymers in aqueous solutions

Garner

Hadar

Skidmore

et al. 2019

J of Applied Polymer Sci

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Polyester–polyether block copolymers with thermogelling properties have been widely used in pharmaceutical and biomedical applications for their biocompatibility and degradation to nontoxic components. The biodegradable polymers, such as poly(lactide‐co‐glycolide) and poly(lactide‐co‐caprolactone) (PLCL), have been used as the polyester block. The most commonly used polyether has been poly(ethylene glycol) (PEG). The thermogelling polymers dissolve in cold water, but become a semisolid gel at higher temperatures, for example, body temperature. This thermogelling property, however, occurs only within very narrow molecular weight ranges of the polyester at given polyether blocks. Only a few hundred Dalton differences in the polyester block can turn a thermogelling polymer into a water‐insoluble polymer. This study describes the hydrophilic and hydrophobic block sizes for endowing the thermogelling property and a simple, water‐free, synthesis of new thermogelling PLCL–PEG–PLCL triblock polymers. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48673.

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Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

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Narrow molecular weight margins for the thermogelling property of polyester–polyether block copolymers in aqueous solutions

Garner

Hadar

Skidmore

et al. 2019

J of Applied Polymer Sci

Self Cite

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“…Most of these products are based on the use of poly(lactic‐co‐glycolic) acid‐based polymers. As such, the FDA has conducted extensive research on characterizing these products to begin to build out a weight of evidence approach that will be effective for this class of products and support the development of in vitro / in vivo correlations . The FDA has linked this advanced characterization with PBPK research into computational methods to predict the performance of long‐acting injectables and quantitative clinical pharmacology (QCP) research into more efficient in vivo study designs.…”

Section: Equivalence Of Complex Mixtures and Formulationsmentioning

confidence: 99%

Innovation for Generic Drugs: Science and Research Under the Generic Drug User Fee Amendments of 2012

Lionberger¹

2019

Clin Pharma and Therapeutics

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Regulatory science is science and research intended to improve decision making in a regulatory framework. Improvements in decision making can be in both accuracy (making better decisions) and in efficiency (making faster decisions). Science and research supported by the Generic Drug User Fee Amendments of 2012 (GDUFA) have focused on two innovative methodologies that work together to enable new approaches to development and review of generic drugs: quantitative models and advanced in vitro product characterization. Quantitative models faithfully represent current scientific understanding. They are tools pharmaceutical scientists and clinical pharmacologists use for making better and faster product development decisions. Advances in the in vitro product comparisons provide the measurements of product differences that are the critical input into the models. This paper outlines four areas where science and research funded by GDUFA support synergistic use of models and characterization at critical decision points during generic drug product development and review.

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“…We selected PLGA Expansorb ® 75-7E from Merck KGaA (Darmstadt, Germany), which has the following properties: lactide/glycolide (L/G) ratio of 75/25, a molecular weight (MW) 80-115 kDa, and the end groups are esterified. The physical chemical properties of Expansorb ® 75-7E were similar to the PLGA in the market product Risperdal Consta ® which contains a lactide/glycolide (L/G) ratio of 78/22, a molecular weight (MW)~111 kDa and the end groups are esterified [22]. As the oil phase, we incorporated isopropyl myristate (IPM) or middle chain triglycerides (MCT) to form a microcapsule (MC) structure.…”

Section: Introductionmentioning

confidence: 98%

Risperidone-Loaded PLGA–Lipid Particles with Improved Release Kinetics: Manufacturing and Detailed Characterization by Electron Microscopy and Nano-CT

et al. 2019

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For parenteral controlled drug release, the desired zero order release profile with no lag time is often difficult to achieve. To overcome the undesired lag time of the current commercial risperidone controlled release formulation, we developed PLGA–lipid microcapsules (MCs) and PLGA–lipid microgels (MGs). The lipid phase was composed of middle chain triglycerides (MCT) or isopropylmyristate (IPM). Hydroxystearic acid was used as an oleogelator. The three-dimensional inner structure of Risperidone-loaded MCs and MGs was assessed by using the invasive method of electron microscopy with focused ion beam cutting (FIB-SEM) and the noninvasive method of high-resolution nanoscale X-ray computed tomography (nano-CT). FIB-SEM and nano-CT measurements revealed the presence of highly dispersed spherical structures around two micrometres in size. Drug release kinetics did strongly depend on the used lipid phase and the presence or absence of hydroxystearic acid. We achieved a nearly zero order release without a lag time over 60 days with the MC-MCT formulation. In conclusion, the developed lipid-PLGA microparticles are attractive alternatives to pure PLGA-based particles. The advantages include improved release profiles, which can be easily tuned by the lipid composition.

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A protocol for assay of poly(lactide- co -glycolide) in clinical products

Cited by 51 publications

References 21 publications

Narrow molecular weight margins for the thermogelling property of polyester–polyether block copolymers in aqueous solutions

Narrow molecular weight margins for the thermogelling property of polyester–polyether block copolymers in aqueous solutions

Innovation for Generic Drugs: Science and Research Under the Generic Drug User Fee Amendments of 2012

Risperidone-Loaded PLGA–Lipid Particles with Improved Release Kinetics: Manufacturing and Detailed Characterization by Electron Microscopy and Nano-CT

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