scholarly journals Polymeric Bioadhesive Patch Based on Ketoprofen-Hydrotalcite Hybrid for Local Treatments

Pharmaceutics ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 733
Author(s):  
Cinzia Pagano ◽  
Loredana Latterini ◽  
Alessandro Di Michele ◽  
Francesca Luzi ◽  
Debora Puglia ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Water Solubility ◽  
Pain Treatment ◽  
Crystalline Form ◽  
Local Administration ◽  
Casting Method ◽  
Local Pain ◽  
Improved Stability ◽  
Low Solubility ◽  
Uv Rays

Ketoprofen (KET) represents one of the most common drugs used in the topical treatment of pain and inflammations. However, its potential is rather limited due to the very low solubility and photochemical instability. The local administration of KET by conventional products, such as gels, emulgels, creams, and foams, does not guarantee an efficacious and safe treatment because of its low absorption (due to low solubility) and its sensitivity to UV rays. The photodegradation of KET makes many photoproducts responsible for different adverse effects. In the present work, KET was intercalated into the lamellar anionic clay ZnAl-hydrotalcite (ZnAl-HTlc), obtaining the hybrid ZnAl-KET with improved stability to UV rays and water solubility in comparison to the crystalline form (not intercalated KET). The hybrid was then formulated in autoadhesive patches for local pain treatment. The patches were prepared by casting method starting from a hydrogel based on the biocompatible and bioadhesive polymer NaCMC (Sodium carboxymethycellulose) and glycerol as a plasticizing agent. The introduction of ZnAl-KET in the patch composition demonstrated the improvement in the mechanical properties of the formulation. Moreover, a sustained and complete KET release was obtained within 8 h. This allowed reducing the frequency of anti-inflammatory administration, compared to the conventional formulations.

Mechanical, Barrier, Physicochemical, and Heat Seal Properties of Starch Films Filled with Nanoparticles

2013 ◽  
Vol 25 ◽  
pp. 90-100 ◽  
Author(s):  
Abdorreza Mohammadi Nafchi ◽  
Abd Karim Alias
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Moisture Content ◽  
Water Solubility ◽  
Decomposition Temperature ◽  
Casting Method ◽  
Film Properties ◽  
Starch Films ◽  
Seal Strength ◽  
Mechanical Barrier

The effects of nanoparticles (nanoclay and nanosilicon dioxide) on heat sealability, physicochemical, barrier, and mechanical properties of starch films were investigated. Starch films were prepared by casting method with addition of nanoparticles and plasticizers. All film properties were measured under standard conditions. Mechanical properties of all types of films were increased by incorporation of nanoparticles. Mungbean starch films showed 100% increment in tensile strength by incorporation of nanoclay. Moisture content, water solubility, and WVP of all starch films decreased whereas decomposition temperature of the films was increased by incorporation of nanoparticles. All films were heat sealable, but nanoparticles-incorporated films exhibited better heat sealability than did control films. In summary, the type of starch governed the heat sealability but nanoparticles have potential to improve seal strength of starch films as well as other functional properties.

scholarly journals The Effect of Stereocomplex Polylactide Particles on the Stereocomplexation of High Molecular Weight Polylactide Blends

Polymers ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2018
Author(s):  
Muhammad Samsuri ◽  
Ihsan Iswaldi ◽  
Purba Purnama
Keyword(s):  
Mechanical Properties ◽  
Molecular Weight ◽  
High Molecular Weight ◽  
Nucleating Agent ◽  
Solution Casting ◽  
Casting Method ◽  
Crystalline Fraction ◽  
Crystalline Structures ◽  
Solution Casting Method

Stereocomplexation is one of several approaches for improving polylactide (PLA) properties. The high molecular weight of poly L-lactide (PLLA) and poly D-lactide (PDLA) homopolymers are a constraint during the formation of stereocomplex PLAs (s-PLAs). The presence of s-PLA particles in PLA PLLA/PDLA blends can initiate the formation of s-PLA crystalline structures. We used the solution casting method to study the utilization of s-PLA materials from high molecular weight PLLA/PDLA blends for increasing s-PLA formation. The s-PLA particles initiated the formation of high molecular weight PLLA/PDLA blends, obtaining 49.13% s-PLA and 44.34% of the total crystalline fraction. In addition, the mechanical properties were enhanced through s-PLA crystalline formation and the increasing of total crystallinity of the PLLA/PDLA blends. The s-PLA particles supported initiation for s-PLA formation and acted as a nucleating agent for PLA homopolymers. These unique characteristics of s-PLA particles show potential to overcome the molecular weight limitation for stereocomplexation of PLLA/PDLA blends.

scholarly journals Comparison of Mechanical Properties of PMMA Disks for Digitally Designed Dentures

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1745
Author(s):  
Tamaki Hada ◽  
Manabu Kanazawa ◽  
Maiko Iwaki ◽  
Awutsadaporn Katheng ◽  
Shunsuke Minakuchi
Keyword(s):  
Mechanical Properties ◽  
Flexural Strength ◽  
Water Sorption ◽  
Water Solubility ◽  
Flexural Modulus ◽  
Manufacturing Method ◽  
Heat Curing ◽  
Significant Difference ◽  
Cad Cam ◽  
Curing Method

In this study, the physical properties of a custom block manufactured using a self-polymerizing resin (Custom-block), the commercially available CAD/CAM PMMA disk (PMMA-disk), and a heat-polymerizing resin (Conventional PMMA) were evaluated via three different tests. The Custom-block was polymerized by pouring the self-polymerizing resin into a special tray, and Conventional PMMA was polymerized with a heat-curing method, according to the manufacturer’s recommended procedure. The specimens of each group were subjected to three-point bending, water sorption and solubility, and staining tests. The results showed that the materials met the requirements of the ISO standards in all tests, except for the staining tests. The highest flexural strength was exhibited by the PMMA-disk, followed by the Custom-block and the Conventional PMMA, and a significant difference was observed in the flexural strengths of all the materials (p < 0.001). The Custom-block showed a significantly higher flexural modulus and water solubility. The water sorption and discoloration of the Custom-block were significantly higher than those of the PMMA-disk, but not significantly different from those of the Conventional PMMA. In conclusion, the mechanical properties of the three materials differed depending on the manufacturing method, which considerably affected their flexural strength, flexural modulus, water sorption and solubility, and discoloration.

scholarly journals Properties of AlSi9Cu3 metal matrix micro and nano composites produced via stir casting

2018 ◽  
Vol 16 (1) ◽  
pp. 726-731 ◽  
Author(s):  
Tennur Gülşen Ünal ◽  
Ege Anıl Diler
Keyword(s):  
Mechanical Properties ◽  
Metal Matrix ◽  
Weight Fraction ◽  
Stir Casting ◽  
Mechanical Tests ◽  
Matrix Composites ◽  
Casting Method ◽  
Porosity Formation ◽  
Three Point Bending ◽  
Hardness Values

AbstractThe effects of micro and nano sized reinforcement particles on microstructure and mechanical properties of aluminium alloy-based metal matrix composites were investigated in this study. AlSi9Cu3 alloy was reinforced with micro and nano sized ceramic reinforcement particles at different weight fractions by using a stir casting method. The mechanical tests (hardness, three point bending) were performed to determine the mechanical properties of AlSi9Cu3 alloy-based microcomposites (AMMCs) and nanocomposites (AMMNCs). The experimental results have shown that the size and weight fraction of reinforcement particles have a strong influence on the microstructure and the mechanical properties of AlSi9Cu3 alloy-based microcomposites and nanocomposites. The relative densities of all AMMC and AMMNC samples are lower than unreinforced AlSi9Cu3 alloy due to porosity formation with the increase of weight fraction of reinforcement particles. As weight fraction increases, hardness values of AMMCs and AMMNCs increase. Maximum flexural strength can be obtained at 3.5wt.% for the AMMC sample with microsized Al2O3 particles and at 2wt.% for the AMMNC sample with nano-sized Al2O3 particles. After the weight fractions exceed these values, flexural strengths of both AMMCs and AMMNCs decrease due to clustering of Al2O3 particles.

scholarly journals Synergistic Effect of Halloysite Nanotubes and Glycerol on the Physical Properties of Fish Gelatin Films

Polymers ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 1258 ◽  
Author(s):  
Xiaohu Qiang ◽  
Songyi Zhou ◽  
Zhuo Zhang ◽  
Qiling Quan ◽  
Dajian Huang
Keyword(s):  
Water Resistance ◽  
Water Solubility ◽  
Composite Films ◽  
Halloysite Nanotubes ◽  
Light Transmittance ◽  
Fish Gelatin ◽  
Moisture Uptake ◽  
Casting Method ◽  
Gelatin Films ◽  
Light Region

Fish gelatin (FG)/glycerol (GE)/halloysite (HT) composite films were prepared by casting method. The morphology of the composite films was observed by scanning electron microscopy (SEM). The effects of HT and GE addition on the mechanical properties, water resistance and optical properties of the composites were investigated. Results showed that with increasing GE content, the elongation at composite breaks increased significantly, but their tensile strength (TS) and water resistance decreased. SEM results showed that GE can partly promote HT dispersion in composites. TS and water resistance also increased with the addition of HTs. Well-dispersed HTs in the FG matrix decreased the moisture uptake and water solubility of the composites. All films showed a transparency higher than 80% across the visible light region (400–800 nm), thereby indicating that light transmittance of the resulting nanocomposites was slightly affected by GE and HTs.

Production of Al Metal Matrix Composites by the Stir-Casting Method

2013 ◽  
Vol 592-593 ◽  
pp. 614-617 ◽  
Author(s):  
Konstantinos Anthymidis ◽  
Kostas David ◽  
Pavlos Agrianidis ◽  
Afroditi Trakali
Keyword(s):  
Mechanical Properties ◽  
Metal Matrix Composites ◽  
Automobile Industry ◽  
Metal Matrix ◽  
Aluminum Matrix ◽  
Stir Casting ◽  
Aluminum Matrix Composites ◽  
Matrix Composites ◽  
Casting Method ◽  
Alloy Matrix

It is well known that the addition of ceramic phases in an alloy e.g. aluminum, in form of fibers or particles influences its mechanical properties. This leads to a new generation of materials, which are called metal matrix composites (MMCs). They have found a lot of application during the last twenty-five years due to their low density, high strength and toughness, good fatigue and wear resistance. Aluminum matrix composites reinforced by ceramic particles are well known for their good thermophysical and mechanical properties. As a result, during the last years, there has been a considerable interest in using aluminum metal matrix composites in the automobile industry. Automobile industry use aluminum alloy matrix composites reinforced with SiC or Al2O3 particles for the production of pistons, brake rotors, calipers and liners. However, no reference could be cited in the international literature concerning aluminum reinforced with TiB particles and Fe and Cr, although these composites are very promising for improving the mechanical properties of this metal without significantly alter its corrosion behavior. Several processing techniques have been developed for the production of reinforced aluminum alloys. This paper is concerned with the study of TiB, Fe and Cr reinforced aluminum produced by the stir-casting method.

scholarly journals Effect of Palm Stearin binder to the Mechanical Properties of Alumina using Slip Casting Method

2020 ◽  
Vol 834 ◽  
pp. 012059
Author(s):  
M N Halmy ◽  
S K Alias ◽  
M A Mat Shah ◽  
M K Maryam ◽  
M A Abu Bakar ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Slip Casting ◽  
Palm Stearin ◽  
Casting Method
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