scholarly journals Amphiphilic Block Copolymer Microspheres Derived from Castor Oil, Poly(ε-carpolactone), and Poly(ethylene glycol): Preparation, Characterization and Application in Naltrexone Drug Delivery

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1996 ◽  
Author(s):  
Maria Nerantzaki ◽  
Eirini Skoufa ◽  
Kyriakos-Vasileios Adam ◽  
Stavroula Nanaki ◽  
Apostolos Avgeropoulos ◽  
...  
Keyword(s):  
Drug Release ◽  
Ethylene Glycol ◽  
Castor Oil ◽  
In Vitro Dissolution ◽  
Release Mechanism ◽  
Release Kinetic ◽  
Burst Release ◽  
Poly Ethylene Glycol ◽  
Long Term Treatment ◽  
Poly Ethylene

In the present study, the newly synthesized castor oil-derived thioether-containing ω-hydroxyacid (TEHA) block copolymers with polycaprolactone (TEHA-b-PCL), with methoxypoly(ethylene glycol) (mPEG), (TEHA-b-mPEG) and with poly(ethylene glycol) (PEG) (TEHA-b-PEG-b-TEHA), were investigated as polymeric carriers for fabrication of naltrexone (NLX)-loaded microspheres by the single emulsion solvent evaporation technique. These microspheres are appropriate for the long-term treatment of opioid/alcohol dependence. Physical properties of the obtained microspheres were characterized in terms of size, morphology, drug loading capacity, and drug release. A scanning electron microscopy study revealed that the desired NLX-loaded uniform microspheres with a mean particle size of 5–10 µm were obtained in all cases. The maximum percentage encapsulation efficiency was found to be about 25.9% for the microspheres obtained from the TEHA-b-PEG-b-TEHA copolymer. Differential scanning calorimetry and X-ray diffractometry analysis confirmed the drug entrapment within microspheres in the amorphous state. In vitro dissolution studies revealed that all NLX-loaded formulations had a similar drug release profile: An initial burst release after 24 h, followed by a sustained and slower drug release for up to 50 days. The analysis of the release kinetic data, which were fitted into the Korsmeyer–Peppas release model, indicated that diffusion is the main release mechanism of NLX from TEHA-b-PCL and TEHA-b-mPEG microspheres, while microspheres obtained from TEHA-b-PEG-b-TEHA exhibited a drug release closer to an erosion process.

“Design of Poly(ethylene glycol)-Polycaprolactone Diblock Micelles with RGD Targeting Ligands and Embedded Iron Oxide Nanoparticles for Thermally-activated Release”

2012 ◽  
Vol 1416 ◽  
Author(s):  
Christopher S. Brazel ◽  
James B. Bennett ◽  
Amanda L. Glover ◽  
Jacqueline A. Nikles ◽  
Maaike Everts ◽  
...  
Keyword(s):  
Magnetic Nanoparticles ◽  
Drug Release ◽  
Ethylene Glycol ◽  
Melting Transition ◽  
Release Mechanism ◽  
Poly Ethylene Glycol ◽  
Rgd Peptides ◽  
Thermally Activated ◽  
Poly Ethylene

ABSTRACTA thermally-activated micelle consisting of a crystallizable poly(caprolactone), PCL, core and a poly(ethylene glycol), PEG, corona was developed to contain magnetic nanoparticles and anti-cancer agent doxorubicin as well as display a targeting RGD peptide. This system has the potential to target cancer cells, deliver combination hyperthermia and chemotherapy, and offer magnetic resonance imaging contrast. The micelles self-assemble in aqueous solutions and form a crystalline core with a melting transition ranging from 40 to 50 °C, depending on the length of the PCL blocks, with dynamic light scattering showing micelle sizes typically ranging from 20 to 100 nm, depending on block lengths and added drug or nanoparticles. The micelles become unstable as they are heated above their melting point, creating a thermally-activated drug release mechanism. By adding magnetite (Fe3O4) nanoparticles into the PCL core, the micelles can be heated using an externally applied AC magnetic field to induce hyperthermia in combination with the thermally-activated drug release. The polymers and magnetic nanoparticles (MNPs) were synthesized and characterized in our laboratories. The melting transitions of the PCL micelle cores were investigated using microcalorimetry. The heating of nanoparticles and magnetomicelles was conducted using a custom-built hyperthermia coil capable of generating fields of several hundred Oersteds at frequencies ranging from 50 to 450 kHz. Heating of MNPs was maximized at high field intensities. RGD peptides were attached to the PEG corona using maleimide chemistry, and the ability of the RGD-derivatized micelles to target integrin-expressing cells was investigated using fluorescent dye PKH26 to identify the localization of micelles in cultured human kidney (293) cells in vitro. The crystallizable (and meltable) cores in these micelles were designed to overcome drug leakage common in liposome systems and release the drug on demand after a period of time for localization to integrin receptors.

scholarly journals Hydrogels Based on Poly(Ether-Ester)s as Highly Controlled 5-Fluorouracil Delivery Systems—Synthesis and Characterization

Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 98
Author(s):  
Adam Kasiński ◽  
Monika Zielińska-Pisklak ◽  
Ewa Oledzka ◽  
Grzegorz Nałęcz-Jawecki ◽  
Agata Drobniewska ◽  
...  
Keyword(s):  
Drug Release ◽  
Ethylene Glycol ◽  
Gel Permeation Chromatography ◽  
Zero Order ◽  
Hexamethylene Diisocyanate ◽  
Release Mechanism ◽  
Poly Ethylene Glycol ◽  
First Order ◽  
Poly Ethylene

A novel and promising hydrogel drug delivery system (DDS) capable of releasing 5‑fluorouracil (5-FU) in a prolonged and controlled manner was obtained using ε‑caprolactone‑poly(ethylene glycol) (CL-PEG) or rac‑lactide-poly(ethylene glycol) (rac‑LA-PEG) copolymers. Copolymers were synthesized via the ring-opening polymerization (ROP) process of cyclic monomers, ε‑caprolactone (CL) or rac-lactide (rac-LA), in the presence of zirconium(IV) octoate (Zr(Oct)4) and poly(ethylene glycol) 200 (PEG 200) as catalyst and initiator, respectively. Obtained triblock copolymers were characterized by nuclear magnetic resonance (NMR) and gel permeation chromatography (GPC) techniques; the structure and tacticity of the macromolecules were determined. The relationship between the copolymer structure and the reaction conditions was evaluated. The optimal conditions were specified as 140 °C and 24 h. In the next step, CL-PEG and rac-LA-PEG copolymers were chemically crosslinked using hexamethylene diisocyanate (HDI). Selected hydrogels were subjected to in vitro antitumor drug release studies, and the release data were analyzed using zero-order, first-order, and Korsmeyer-Peppas mathematical models. Controlled and prolonged (up to 432 h) 5-FU release profiles were observed for all examined hydrogels with first-order or zero-order kinetics. The drug release mechanism was generally denoted as non-Fickian transport.

Reversibly cross-linked poly(ethylene glycol)–poly(amino acid)s copolymer micelles: a promising approach to overcome the extracellular stability versus intracellular drug release challenge

RSC Advances ◽  
2015 ◽  
Vol 5 (26) ◽  
pp. 20025-20034 ◽  
Author(s):  
Yuling Li ◽  
Sai Wang ◽  
Dandan Zhu ◽  
Yuling Shen ◽  
Baixiang Du ◽  
...  
Keyword(s):  
Amino Acid ◽  
Drug Release ◽  
Ethylene Glycol ◽  
Lipoic Acid ◽  
Triblock Copolymer ◽  
Intracellular Delivery ◽  
Poly Ethylene Glycol ◽  
Copolymer Micelles ◽  
Poly Ethylene ◽  
Copolymer Poly

Reversibly shell cross-linked micelles based on a lipoic acid (LA) decorated triblock copolymer poly(ethylene glycol)-b-poly(γ-benzyl-l-glutamate)-b-poly(l-phenylalanine) have been developed for efficient intracellular delivery of DOX.

Controlled Release Behaviors of Ketoprofen from Matrix Polymer of Chitosan and poly(ethylene glycol)

2013 ◽  
Vol 813 ◽  
pp. 399-402
Author(s):  
Chimsook Thitipha ◽  
Thitiphan Chimsook
Keyword(s):  
Particle Size ◽  
Controlled Release ◽  
Drug Release ◽  
Ethylene Glycol ◽  
Diffusion Method ◽  
Poly Ethylene Glycol ◽  
Matrix Polymer ◽  
Percentage Yield ◽  
Poly Ethylene ◽  
Composition Ratios

The aim of present work was to prepare floating microsphere of ketoprofen using matrix polymer of chitosan and poly (ethylene glycol) by solvent diffusion method. The floating microsphere of ketoprofen was prepared from matrix polymer of chitosan and poly (ethylene glycol) with various composition ratios and evaluated such as particle size, drug compatibility and drug release of microspheres. The scanning electron microscopy of microspheres confirmed their hollow structures with smooth surface. Formulation CPK 4 to CPK 6 exhibited the best controlled release pattern in ketoprofen. The concentration and size of poly (ethylene-glycol) affected the particle size, percentage yield and drug release of microspheres.

scholarly journals Hydrolysis and drug release from poly(ethylene glycol)-modified lactone polymers with open porosity

2019 ◽  
Vol 113 ◽  
pp. 165-175 ◽  
Author(s):  
Sanja Asikainen ◽  
Kaarlo Paakinaho ◽  
Anna-Kaisa Kyhkynen ◽  
Markus Hannula ◽  
Minna Malin ◽  
...  
Keyword(s):  
Drug Release ◽  
Ethylene Glycol ◽  
Open Porosity ◽  
Poly Ethylene Glycol ◽  
Poly Ethylene

scholarly journals Evaluation and Optimization of Influence of Permeability Property and Concentration of Polymethacrylic Polymers on Microspheres of Metformin HCl

2014 ◽  
Vol 12 (2) ◽  
pp. 131-141 ◽  
Author(s):  
Ikramul Hasan ◽  
Shovan Paul ◽  
Sharmin Akhter ◽  
Navid Jubaer Ayon ◽  
Md Selim Reza
Keyword(s):  
Particle Size ◽  
Drug Release ◽  
Surface Morphology ◽  
Drug Loading ◽  
Liquid Paraffin ◽  
In Vitro Dissolution ◽  
Release Mechanism ◽  
Release Kinetic ◽  
Eudragit Rlpo ◽  
Metformin Hcl

Metformin HCl microspheres were prepared with the aim of increasing its bioavailability and decreasing gastrointestinal side effects by means of sustained action. Eudragit RSPO and Eudragit RLPO, polymers of different permeability characteristics were used to prepare different microspheres. Emulsification solvent evaporation technique using acetone as the internal phase and liquid paraffin as the external phase was the method of choice. Six formulations were prepared using two polymers. The effect of drug loading and polymeric property on the surface morphology, entrapment efficiency, particle size and release characteristics of the microspheres were examined. FTIR and DSC studies established compatibility of the drug with the polymers. SEM studies clearly revealed the effect of drug loading and polymeric nature on the surface morphology of the microspheres. Entrapment efficiencies were within 77.09-97.11% and particle size of all the batches were in the acceptable range. Release data were treated with different mathematical kinetic models. The drug release profile showed that Eudragit RSPO and Eudragit RLPO have opposite effect on drug release. On the other hand, increase in drug loading results in increased drug release. Kinetic modeling of in vitro dissolution profiles revealed that the drug release mechanism varies from diffusion controlled to anomalous type. Dhaka Univ. J. Pharm. Sci. 12(2): 131-141, 2013 (December) DOI: http://dx.doi.org/10.3329/dujps.v12i2.17611

Star-shaped poly(l-lactide)-b-poly(ethylene glycol) with porphyrin core: synthesis, self-assembly, drug-release behavior and singlet oxygen research

2014 ◽  
Vol 38 (8) ◽  
pp. 3569-3578 ◽  
Author(s):  
Xiao-Hui Dai ◽  
Zhi-Ming Wang ◽  
Lu-You Gao ◽  
Jian-Ming Pan ◽  
Xiao-Hong Wang ◽  
...  
Keyword(s):  
Photodynamic Therapy ◽  
Block Copolymer ◽  
Drug Release ◽  
Ethylene Glycol ◽  
Self Assembly ◽  
Release Behavior ◽  
Poly Ethylene Glycol ◽  
Drug Release Behavior ◽  
Porphyrin Core ◽  
Poly Ethylene

pH-induced block copolymer SPPLA-b-PEG with porphyrin core for photodynamic therapy.

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