Controlling Burst and Final Drug Release Times from Porous Polylactide Devices Derived from Co-continuous Polymer Blends

2009 ◽  
Vol 10 (8) ◽  
pp. 2053-2066 ◽  
Author(s):  
Zhenyu Xiang ◽  
Pierre Sarazin ◽  
Basil D. Favis
Keyword(s):  
Drug Release ◽  
Polymer Blends ◽  
Release Times

In vitro degradation and drug release from polymer blends based on poly(dl-lactide), poly(l-lactide-glycolide) and poly(ε-caprolactone)

2009 ◽  
Vol 45 (5) ◽  
pp. 1284-1292 ◽  
Author(s):  
Paul F. McDonald ◽  
John G. Lyons ◽  
Luke M. Geever ◽  
Clement L. Higginbotham
Keyword(s):  
Drug Release ◽  
Polymer Blends ◽  
In Vitro Degradation

pH-Sensitive Polymer Blends used as Coating Materials to Control Drug Release from Spherical Beads:  Importance of the Type of Core

2005 ◽  
Vol 6 (4) ◽  
pp. 2074-2083 ◽  
Author(s):  
Florence Lecomte ◽  
Juergen Siepmann ◽  
Mathias Walther ◽  
Ross J. MacRae ◽  
Roland Bodmeier
Keyword(s):  
Drug Release ◽  
Polymer Blends ◽  
Ph Sensitive ◽  
Coating Materials ◽  
Control Drug ◽  
Ph Sensitive Polymer ◽  
Control Drug Release

Porous Devices Derived from Co-Continuous Polymer Blends as a Route for Controlled Drug Release

2008 ◽  
Vol 9 (4) ◽  
pp. 1131-1138 ◽  
Author(s):  
Pouneh Salehi ◽  
Pierre Sarazin ◽  
Basil D. Favis
Keyword(s):  
Drug Release ◽  
Polymer Blends ◽  
Controlled Drug Release

scholarly journals Eudraginated polymer blends: A potential oral controlled drug delivery system for theophylline

2012 ◽  
Vol 62 (1) ◽  
pp. 71-82 ◽  
Author(s):  
Martins Emeje ◽  
Lucy John-Africa ◽  
Yetunde Isimi ◽  
Olobayo Kunle ◽  
Sabinus Ofoefule
Keyword(s):  
Drug Delivery ◽  
Drug Release ◽  
Sustained Release ◽  
Polymer Blends ◽  
Drug Delivery System ◽  
Delivery System ◽  
Controlled Drug Delivery ◽  
Dosage Forms ◽  
Controlled Drug Delivery System

Eudraginated polymer blends: A potential oral controlled drug delivery system for theophylline Sustained release (SR) dosage forms enable prolonged and continuous deposition of the drug in the gastrointestinal (GI) tract and improve the bioavailability of medications characterized by a narrow absorption window. In this study, a new strategy is proposed for the development of SR dosage forms for theophylline (TPH). Design of the delivery system was based on a sustained release formulation, with a modified coating technique and swelling features aimed to extend the release time of the drug. Different polymers, such as Carbopol 71G (CP), sodium carboxymethylcellulose (SCMC), ethylcellulose (EC) and their combinations were tried. Prepared matrix tablets were coated with a 5 % (m/m) dispersion of Eudragit (EUD) in order to get the desired sustained release profile over a period of 24 h. Various formulations were evaluated for micromeritic properties, drug concentration and in vitro drug release. It was found that the in vitro drug release rate decreased with increasing the amount of polymer. Coating with EUD resulted in a significant lag phase in the first two hours of dissolution in the acidic pH of simulated gastric fluid (SGF) due to decreased water uptake, and hence decreased driving force for drug release. Release became faster in the alkaline pH of simulated intestinal fluid (SIF) owing to increased solubility of both the coating and matrixing agents. The optimized formulation was subjected to in vivo studies in rabbits and the pharmacokinetic parameters of developed formulations were compared with the commercial (Asmanyl®) formulation. Asmanyl® tablets showed faster absorption (tmax 4.0 h) compared to the TPH formulation showing a tmax value of 8.0 h. The Cmax and AUC values of TPH formulation were significantly (p < 0.05) higher than those for Asmanyl®, revealing relative bioavailability of about 136.93 %. Our study demonstrated the potential usefulness of eudraginated polymers for the oral delivery of the sparingly soluble drug theophylline.

scholarly journals Preparation and Loading with Rifampicin of Sub-50 nm Poly(ethyl cyanoacrylate) Nanoparticles by Semicontinuous Heterophase Polymerization

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
H. Saade ◽  
C. Barrera ◽  
R. Guerrero ◽  
E. Mendizábal ◽  
J. E. Puig ◽  
...  
Keyword(s):  
Drug Release ◽  
Aqueous Dispersions ◽  
Molecular Weights ◽  
Heterophase Polymerization ◽  
Release Times ◽  
Addition Rate ◽  
Nanoparticle Structure ◽  
Ethyl Cyanoacrylate ◽  
Two Populations ◽  
Semicontinuous Heterophase Polymerization

We report the preparation of poly(ethyl cyanoacrylate) (PECA) nanoparticles by semicontinuous heterophase polymerization carried out at monomer starved conditions at three monomer addition rates. Particles in the nanometer range were obtained, the size of which diminishes with decreasing monomer addition rate as shown by the fact that particles with mean diameters of ca. 42 and 30 nm were obtained at the faster and intermediate dosing rates, respectively, whereas two populations of particles, one of 15.5 and the other of 36 nm in mean diameters, were produced at the slower dosing rate. The obtained molecular weights were from 2,200 to 3,500 g/mol, depending on the addition rate, which are typical of the anionic polymerizations of cyanoacrylates in aqueous dispersions at low pHs. The rifampicin (RIF) loading into the nanoparticles was successful since the entire drug added was incorporated. The drug release study carried out at pH of 7.2 indicated a faster release from the free RIF at intermediate and larger release times as expected since, in the nanoparticles, first the drug has to diffuse through the nanoparticle structure. The comparison of several drug release models indicates that the RIF release from PECA nanoparticles follows that of Higuchi.

scholarly journals Risperidone Controlled Release Microspheres Based on Poly(Lactic Acid)-Poly(Propylene Adipate) Novel Polymer Blends Appropriate for Long Acting Injectable Formulations

Pharmaceutics ◽  
2018 ◽  
Vol 10 (3) ◽  
pp. 130 ◽  
Author(s):  
Stavroula Nanaki ◽  
Panagiotis Barmpalexis ◽  
Alexandros Iatrou ◽  
Evi Christodoulou ◽  
Margaritis Kostoglou ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Controlled Release ◽  
Drug Release ◽  
Polymer Blends ◽  
Solvent Evaporation ◽  
Poly Lactic Acid ◽  
Solvent Evaporation Method ◽  
Evaporation Method ◽  
Long Acting ◽  
Poly Propylene

The present study evaluates the preparation of risperidone controlled release microspheres as appropriate long-acting injectable formulations based on a series of novel biodegradable and biocompatible poly(lactic acid)–poly(propylene adipate) (PLA/PPAd) polymer blends. Initially, PPAd was synthesized using a two-stage melt polycondensation method (esterification and polycondensation) and characterized by 1H-NMR, differential scanning calorimetry (DSC), and powder X-ray diffraction (XRD) analyses. DSC and XRD results for PLA/PPAd blends (prepared by the solvent evaporation method) showed that these are immiscible, while enzymatic hydrolysis studies performed at 37 °C showed increased mass loss for PPAd compared to PLA. Risperidone-polyester microparticles prepared by the oil–water emulsification/solvent evaporation method showed smooth spherical surface with particle sizes from 1 to 15 μm. DSC, XRD, and Fourier-transformed infrared (FTIR) analyses showed that the active pharmaceutical ingredient (API) was dispersed in the amorphous phase within the polymer matrices, whereas in vitro drug release studies showed risperidone controlled release rates in all PLA/PPAd blend formulations. Finally, statistical moment analysis showed that polyester hydrolysis had a major impact on API release kinetics, while in PLA/PPAd blends with high PLA content, drug release was mainly controlled by diffusion.

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