scholarly journals Degradable Polymer Films Made from Poly(salicylic‐acid‐ co ‐sebacic acid) and Poly(sebacic anhydride)/Poly(adipic anhydride) Blends: Degradation Kinetics and Use as Sacrificial Layers for Polymer Multilayer Systems

2020 ◽  
Vol 221 (12) ◽  
pp. 2000106
Author(s):  
Zhuoling Deng ◽  
Esther K. Riga ◽  
Karen Lienkamp
Keyword(s):  
Salicylic Acid ◽  
Polymer Films ◽  
Degradation Kinetics ◽  
Sebacic Acid ◽  
Multilayer Systems ◽  
Degradable Polymer ◽  
Sacrificial Layers

Processing Considerations for Salicylic Acid-Based Polymers

2003 ◽  
Author(s):  
Eva Wagner ◽  
Kathryn Uhrich ◽  
Thomas Twardowski
Keyword(s):  
Salicylic Acid ◽  
Controlled Release ◽  
Temperature Dependence ◽  
Medical Devices ◽  
Melt Processing ◽  
The Body ◽  
Hollow Fibers ◽  
New Approach ◽  
Degradable Polymer ◽  
Solution Spinning

This paper describes some of the processing issues for extruding salicylic acid-based polymer prodrugs into fibers for medical devices. Polymeric prodrugs, in which a drug is polymerized in a degradable polymer that delivers controlled quantity of the drug to a targeted site in the body as the device degrades, are a new approach to controlled release. Hollow fibers were produced by solution spinning. Solid fibers were formed by melt processing. The salicylic acid polymers exhibited shear-thinning behavior. The viscosity exhibited pronounced temperature dependence.

scholarly journals Influence of Polymer Composition on the Controlled Release of Docetaxel: A Comparison of Non-Degradable Polymer Films for Oesophageal Drug-Eluting Stents

Pharmaceutics ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 444 ◽  
Author(s):  
Paris Fouladian ◽  
Franklin Afinjuomo ◽  
Mohammad Arafat ◽  
Amanda Bergamin ◽  
Yunmei Song ◽  
...  
Keyword(s):  
Polymer Films ◽  
Degradation Products ◽  
Clinical Success ◽  
In Vitro Release ◽  
Polymer Composition ◽  
Drug Eluting Stents ◽  
Scanning Calorimetry ◽  
Vascular Stents ◽  
Degradable Polymer ◽  
Drug Eluting

Following the huge clinical success of drug-eluting vascular stents, there is a significant interest in the development of drug-eluting stents for other applications, such as the treatment of gastrointestinal (GI) cancers. Central to this process is understanding how particular drugs are released from stent coatings, which to a large extent is controlled by drug-polymer interactions. Therefore, in this study we investigated the release of docetaxel (DTX) from a selection of non-degradable polymer films. DTX-polymer films were prepared at various loadings (1, 5 and 10% w/w) using three commercially available polymers including poly(dimethylsiloxane) (PSi), poly (ethylene-co-vinyl acetate) (PEVA) and Chronosil polyurethane (PU). The formulations were characterised using different techniques such as photoacoustic Fourier-transform infrared (PA-FTIR) spectrophotometry, X-ray diffraction (XRD) and differential scanning calorimetry (DSC). The effect of DTX on the mechanical properties of the films, in-vitro release, and degradation tests were also assessed. For all polymers and DTX loadings, the drug was found to disperse homogenously without crystallisation within the polymer matrix. While no specific interactions were observed between DTX and PSi or PEVA, hydrogen-bonding appeared to be present between DTX and PU, which resulted in a concentration-dependent decrease in the Young’s moduli of the films due to disruption of inter-polymeric molecular interactions. In addition, the DTX-PU interactions were found to modulate drug release, providing near-linear release over 30 days, which was accompanied by a significant reduction in degradation products. The results indicate that DTX-loaded PU films are excellent candidates for drug-eluting stents for the treatment of oesophageal cancer.

Thin polymer films as sacrificial layers for easier cleaning

2010 ◽  
Vol 358 (1-3) ◽  
pp. 6-12 ◽  
Author(s):  
Wiebe M. de Vos ◽  
Arie de Keizer ◽  
Martien A. Cohen Stuart ◽  
J. Mieke Kleijn
Keyword(s):  
Polymer Films ◽  
Thin Polymer Films ◽  
Thin Polymer ◽  
Sacrificial Layers

Degradation methods and degradation kinetics of polymer films

1994 ◽  
Vol 45 (2) ◽  
pp. 165-172 ◽  
Author(s):  
D.L. Kaplan ◽  
J.M. Mayer ◽  
M. Greenberger ◽  
R. Gross ◽  
S. McCarthy
Keyword(s):  
Polymer Films ◽  
Degradation Kinetics ◽  
Kinetics Of

Effect of Pd Nanoparticles on Thermal Degradation Kinetics of iPP/Pd Nanocomposite

2010 ◽  
Vol 123-125 ◽  
pp. 651-654
Author(s):  
Jae Young Lee ◽  
Bum Choul Choi ◽  
Ji Jung Lee ◽  
Sung Won Yang ◽  
Hong Ki Lee
Keyword(s):  
Thermal Degradation ◽  
Polymer Films ◽  
Degradation Kinetics ◽  
Pd Nanoparticles ◽  
Nitrogen Atmosphere ◽  
Thermal Degradation Kinetics ◽  
Processing Temperature ◽  
Heating Rates ◽  
Free Standing ◽  
Dry Process

Palladium (Pd) nanoparticles were incorporated into free-standing polymer films, where isotactic polypropylene (iPP) was used, by a one-step dry process involving simultaneous vaporization, absorption and reduction schemes of palladium(II) bis(acetylacetonate), Pd(acac)2 at 180oC, used as a precursor. iPP film was exposed to the sublimed Pd(acac)2 vapor in a glass vessel with nitrogen atmosphere heated at 180oC. The exposing time was 30 min and the Pd nanoparticle contents in polymer films were estimated from ash contents in a sample of about 5 mg by pyrolysis of the films at 800 oC for 1 h in an electric furnace of the TGA apparatus under dry argon atmosphere. The sensitivity of the TGA apparatus was 0.2 mg, and thus the minimum content to be measured was 0.004 wt% of a 5 mg sample. The reduced Pd nanoparticles were observed by transmission electron microscope (TEM), and it was found that metal nanoparticles were selectively loaded into the amorphous regions between the lamellae of crystalline polymers having higher melting temperatures than the processing temperature (180 oC). In order to measure the thermal degradation rate, TGA data measured by the heating rates of 5, 10, 15 and 20 oC /min at the nitrogen atmosphere of 200 ml/min. The TGA data was introduced to the Ozawa equation and the degradation activation energy was calculated according to the degradation ratio.

scholarly journals The stability and degradation kinetics of acetylsalicylic acid in different organic solutions revisited – an UHPLC–ESI-QTOF spectrometry study

2016 ◽  
Vol 29 (1) ◽  
pp. 39-41 ◽  
Author(s):  
Robert Skibinski ◽  
Lukasz Komsta
Keyword(s):  
Mass Spectrometry ◽  
Salicylic Acid ◽  
Acetylsalicylic Acid ◽  
High Performance ◽  
Degradation Kinetics ◽  
Water Solution ◽  
Stability Study ◽  
Initial Concentration ◽  
The Stability ◽  
Organic Solutions

Abstract Ultra high performance liquid chromatography (UHPLC), coupled with accurate quadrupole-time-of-flight (Q-TOF) mass spectrometry, was used for the stability study of acetylsalicylic acid within a variety of different organic solutions: methanol, ethanol, propan-2-ol, acetonitrile, tetrahydrofuran and 1,4-dioxane. With the use of gradient elution chromatography and mass spectrometry detection in negative ionization, MS and MS/MS spectra were recorded simultaneously. In addition, quantitative, as well as qualitative analysis was performed during one assay. The stability of acetylsalicylic acid in such solutions was tested at room temperature, in a 12h period. In the work, in all cases, only one main degradation product, salicylic acid, was found. What is more, the work revealed that the degradation of aspirin in the tested organic solutions yields apparent second-order kinetics. The study also demonstrated that acetonitrile and 1,4-dioxane turned out to be the most stable solvents, and an above 80% of initial concentration of acetylsalicylic acid was found in this case. Furthermore, the most popular analytical solvents, methanol and ethanol, were found to be very unstable media. Herein, below 40% of initial concentration of acetylsalicylic acid was seen after 12h. The obtained results were also compared with the degradation of acetylsalicylic acid in a water solution. In this situation, only about 25% of the analyzed compound was resolved to salicylic acid in the same time frame.

Gum arabic helps prepare better lacey polymer films for specimen support in electron microscopy

1993 ◽  
Vol 51 ◽  
pp. 240-241
Author(s):  
Shailesh R. Sheth ◽  
Jayesh R. Bellare
Keyword(s):  
Electron Microscopy ◽  
Polymer Films ◽  
Gum Arabic ◽  
Complete Removal ◽  
Ammonium Bromide ◽  
Release Agent ◽  
Astigmatism Correction ◽  
Long Time ◽  
Micro Holes ◽  
Cetyl Trimethyl Ammonium

Specimen support and astigmatism correction in Electron Microscopy are at least two areas in which lacey polymer films find extensive applications. Although their preparation has been studied for a very long time, present techniques still suffer from incomplete release of the film from its substrate and presence of a large number of pseudo holes in the film. Our method ensures complete removal of the entire lacey film from the substrate and fewer pseudo holes by pre-treating the substrate with Gum Arabic, which acts as a film release agent.The method is based on the classical condensation technique for preparing lacey films which is essentially deposition of minute water or ice droplets on the substrate and laying the polymer film over it, so that micro holes are formed corresponding to the droplets. A microscope glass slide (the substrate) is immersed in 2.0% (w/v) aq. CTAB (cetyl trimethyl ammonium bromide)-0.22% (w/v) aq.

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