scholarly journals Study of the Potential Employment of Malvaceae Species in Composites Materials

2015 ◽  
Vol 668 ◽  
pp. 75-85
Author(s):  
Bárbara Maria Gama Guimarães ◽  
Diana Cayuela Marín ◽  
Welton Fernando Zonatti ◽  
Waldir Mantovani ◽  
Cátia Relvas ◽  
...  
Keyword(s):  
Textile Industry ◽  
Rupture Strength ◽  
Physicochemical Characterization ◽  
Scanning Calorimetry ◽  
Vegetal Fibers ◽  
Composites Materials ◽  
Medium Resistance ◽  
Sida Cordifolia ◽  
Malvastrum Coromandelianum

The employ of vegetal fibers for textiles and composites represents a great potential in economic and social sustainable development. Some Malvaceae species are considered tropical cosmopolitans, such as from Sida genus. Several species of this genus provide excellent textile bast fibers, which are very similar in qualities to the jute textile fiber. The objective of the present study is present the physicochemical characterization of six Brazilian vegetal fibers: Sida rhombifolia L.; Sida carpinifolia L. f.; Sidastrum paniculatum (L.) Fryxell; Sida cordifolia L.; Malvastrum coromandelianum (L.) Gurck; Wissadula subpeltata (Kuntze) R.E.Fries. Respectively the two first species are from Brazilian Atlantic Forest biome and the four remaining from Brazilian Cerrado biome, despite of present in other regions of the planet. The stems of these species were retted in water at 37oC for 20 days. The fibers were tested in order to determine tensile rupture strength, tenacity, elongation, Young’s modulus, cross microscopic structure, Scanning Electronic Microscopy (SEM), regain, combustion, acid, alkali, organic solvent and cellulase effects, pH of the aqueous extract, Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA). The obtained values were compared with those from fibers of recognized applicability in the textile industry including hemp. The results are promising in terms of their employment in thermoset and thermoplastic medium resistance composites.

scholarly journals THE PHYSICOCHEMICAL CHARACTERISTICS OF RECYCLED-PLASTIC PELLETS OBTAINED FROM DISPOSABLE FACE MASK WASTES

2021 ◽  
Vol 23 (1) ◽  
pp. 16
Author(s):  
Vienna Saraswaty ◽  
Rossy Choerun Nissa ◽  
Bonita Firdiana ◽  
Akbar Hanif Dawam Abdullah
Keyword(s):  
Tensile Strength ◽  
Physicochemical Characterization ◽  
Face Mask ◽  
Physicochemical Characteristics ◽  
Scanning Calorimetry ◽  
Elongation At Break ◽  
Ft Ir ◽  
The Government ◽  
Plastic Pellets

THE PHYSICOCHEMICAL CHARACTERISTICS OF RECYCLED-PLASTIC PELLETS OBTAINED FROM DISPOSABLE FACE MASK WASTES. The government policy to wear a face mask during the COVID-19 pandemic has increased disposable face mask wastes. Thus, to reduce such wastes, it is necessary to evaluate the physicochemical characteristics of disposable face masks wastes before the recycling process and the recycled products. In this study, physicochemical characterization of the 3-ply disposable face masks and the recycled plastic pellets after disinfection using 0.5% v/v sodium hypochlorite were evaluated. A set of parameters including the characterization of surface morphology by a scanning electron microscope (SEM), functional groups properties by a fourier transform infra-red spectroscopy (FT-IR), thermal behavior by a differential scanning calorimetry (DSC), tensile strength and elongation at break were evaluated. The surface morphological of each layer 3-ply disposable face mask showed that the layers were composed of non-woven fibers. The FT-IR evaluation revealed that 3-ply disposable face mask was made from a polypropylene. At the same time, the DSC analysis found that the polypropylene was in the form of homopolymer. The SEM analysis showed that the recycled plastic pellets showed a rough and uneven surface. The FT-IR, tensile strength and elongation at break of the recycled plastic pellets showed similarity with a virgin PP type CP442XP and a recycled PP from secondary recycling PP (COPLAST COMPANY). In summary, recycling 3-ply disposable face mask wastes to become plastic pellets is recommended for handling disposable face mask wastes problem.

scholarly journals Development of High Dose Oseltamivir Phosphate Dry Powder for Inhalation Therapy in Viral Pneumonia

Pharmaceutics ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 1154
Author(s):  
Shahir Aziz ◽  
Regina Scherlieβ ◽  
Hartwig Steckel
Keyword(s):  
Virus Disease ◽  
Antiviral Drug ◽  
Physicochemical Characterization ◽  
Inhalation Therapy ◽  
High Dose ◽  
Dry Powder ◽  
Medium Resistance ◽  
High Doses ◽  
Oseltamivir Phosphate

Oseltamivir phosphate (OP) is an antiviral drug available only as oral therapy for the treatment of influenza and as a potential treatment option when in combination with other medication in the fight against the corona virus disease (COVID-19) pneumonia. In this study, OP was formulated as a dry powder for inhalation, which allows drug targeting to the site of action and potentially reduces the dose, aiming a more efficient therapy. Binary formulations were based on micronized excipient particles acting like diluents, which were blended with the drug OP. Different excipient types, excipient ratios, and excipient size distributions were prepared and examined. To investigate the feasibility of delivering high doses of OP in a single dose, 1:1, 1:3, and 3:1 drug/diluent blending ratios have been prepared. Subsequently, the aerosolization performance was evaluated for all prepared formulations by cascade impaction using a novel medium-resistance capsule-based inhaler (UNI-Haler). Formulations with micronized trehalose showed relatively excellent aerosolization performance with highest fine-particle doses in comparison to examined lactose, mannitol, and glucose under similar conditions. Focusing on the trehalose-based dry-powder inhalers’ (DPIs) formulations, a physicochemical characterization of extra micronized grade trehalose in relation to the achieved performance in dispersing OP was performed. Additionally, an early indication of inhaled OP safety on lung cells was noted by the viability MTT assay utilizing Calu-3 cells.

scholarly journals Preparation and Physicochemical Characterization of Softgels Cross-Linked with Cactus Mucilage Extracted from Cladodes of Opuntia Ficus-Indica

Molecules ◽  
2019 ◽  
Vol 24 (14) ◽  
pp. 2531 ◽  
Author(s):  
Luis R. Camelo Caballero ◽  
Andrea Wilches-Torres ◽  
Agobardo Cárdenas-Chaparro ◽  
Jovanny A. Gómez Castaño ◽  
María Carolina Otálora
Keyword(s):  
Physicochemical Characterization ◽  
Wall Material ◽  
Scanning Calorimetry ◽  
Nutritional Properties ◽  
Solubility In Water ◽  
Prepared Composite ◽  
Cactus Mucilage ◽  
Composite Samples ◽  
Vibrational Characterization

A new crosslinking formulation using gelatin (G) and cactus mucilage (CM) biopolymers was developed, physicochemically characterized and proposed as an alternative wall material to traditional gelatin capsules (softgels). The effect of G concentration at different G/CM ratios (3:1, 1:1 and 1:3) was analyzed. Transparency, moisture content (MC), solubility in water (SW), morphology (scanning electron microscopy, SEM), vibrational characterization (Fourier transform infrared, FTIR), color parameters (CIELab) and thermal (differential scanning calorimetry/thermogravimetric analysis, DSC/TGA) properties of the prepared composite (CMC) capsules were estimated and compared with control (CC) capsules containing only G and glycerol. In addition, the dietary fiber (DF) content was also evaluated. Our results showed that the transparency of composite samples decreased gradually with the presence of CM, the G/CM ratio of 3:1 being suitable to form the softgels. The addition of CM decreased the MC, the SW and the lightness of the capsules. Furthermore, the presence of polysaccharide had significant effects on the morphology and thermal behavior of CMC in contrast to CC. FTIR spectra confirmed the CMC formation by crosslinking between CM and G biopolymers. The addition of CM to the softgels formulation influenced the DF content. Our findings support the feasibility of developing softgels using a formulation of CM and G as wall material with nutritional properties.

Preparation and characterization of titanium—segmented polyurethane composites for bone tissue engineering

2018 ◽  
Vol 33 (1) ◽  
pp. 11-22 ◽  
Author(s):  
Fernando Javier Aguilar-Perez ◽  
Rossana Vargas-Coronado ◽  
Jose Manuel Cervantes-Uc ◽  
Juan Valerio Cauich-Rodriguez ◽  
Raul Rosales-Ibañez ◽  
...  
Keyword(s):  
Stem Cells ◽  
Dental Pulp ◽  
Soft Segment ◽  
Physicochemical Characterization ◽  
Dental Pulp Stem Cells ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Human Dental Pulp ◽  
Polyurethane Composites

Segmented polyurethanes were prepared with polycaprolactone diol as soft segment and 4,4-methylene-bis cyclohexyl diisocyanate and l-glutamine as the rigid segment. These polyurethanes were filled with 1 wt.% to 5 wt.% titanium particles (Ti), physicochemically characterized and their biocompatibility assessed using human dental pulp stem cells and mice osteoblasts. Physicochemical characterization showed that composites retained the properties of the semicrystalline polyurethane as they exhibited a glass transition temperature (Tg) between −35°C and −45°C, melting temperature (Tm) at 52°C and crystallinity close to 40% as determined by differential scanning calorimetry. In agreement with this, X-ray diffraction showed reflections at 21.3° and 23.6° for polycaprolactone diol and reflections at 35.1°, 38.4°, and 40.2° for Ti particles suggesting that these particles are not acting as nucleating sites. The addition of up to 5 wt.% of Ti reduced both, tensile strength and maximum strain from 1.9 MPa to 1.2 MPa, and from 670% to 172% for pristine and filled polyurethane, respectively. Although there were differences between composites at low strain rates, no significant differences in mechanical behavior were observed at higher strain rate where a tensile stress of 8.5 MPa and strain of 223% were observed for 5 wt.% composites. The addition to titanium particles had a beneficial effect on both human dental pulp stem cells and osteoblasts viability, as it increased with the amount of titanium in composites up to 10 days of incubation.

Physicochemical Characterization of Arrowroot Starch (Maranta arundinacea Linn) and Glycerol/Arrowroot Starch Membranes

2014 ◽  
Vol 10 (4) ◽  
pp. 727-735 ◽  
Author(s):  
Carlos Andrés Sandoval Gordillo ◽  
Germán Ayala Valencia ◽  
Rubén Antonio Vargas Zapata ◽  
Ana Cecilia Agudelo Henao
Keyword(s):  
Thermal Properties ◽  
Amylose Content ◽  
Starch Content ◽  
Physicochemical Characterization ◽  
Industrial Applications ◽  
Glycerol Content ◽  
Scanning Calorimetry ◽  
Size Dispersion ◽  
Arrowroot Starch

Abstract In the current work, physicochemical properties of arrowroot starch and thermal properties of glycerol/arrowroot starch membranes were investigated. Arrowroot starch exhibited high purity (starch content >99%) with amylose content >40% and granule size dispersion between 29 and 126 μm. Arrowroot starch has a gelatinization temperature of 63.94°C and a B-type crystalline structure. Arrowroot starch, in combination with three levels of glycerol, was used to manufacture membranes by casting method. Increasing the plasticizer effect due to glycerol content increased the water weight loss of the membranes at temperatures higher than 110°C. Additionally, the onset temperature of the endothermic peak observed by differential scanning calorimetry and associated to water removal from the membranes changed with glycerol content. Physicochemical and thermal properties of arrowroot starch and glycerol/arrowroot starch membranes were similar to those reported previously for other starch sources. From the data obtained in this study, it is clear that arrowroot starch could have promising industrial applications.

scholarly journals Preparation and physicochemical characterization of Eudragit® RL100 Nanosuspension with potential for Ocular Delivery of Sulfacetamide

2010 ◽  
Vol 13 (4) ◽  
pp. 510 ◽  
Author(s):  
Bivash Mandal ◽  
Kenneth S Alexander ◽  
Alan T Riga
Keyword(s):  
Zeta Potential ◽  
Bacterial Infections ◽  
Room Temperature ◽  
In Vitro Release ◽  
Physicochemical Characterization ◽  
Entrapment Efficiency ◽  
Scanning Calorimetry ◽  
Freeze Dried ◽  
Drug Entrapment Efficiency

Purpose: Polymeric nanosuspension was prepared from an inert polymer resin (Eudragit® RL100) with the aim of improving the availability of sulfacetamide at the intraocular level to combat bacterial infections. Methods: Nanosuspensions were prepared by the solvent displacement method using acetone and Pluronic® F108 solution. Drug to polymer ratio was selected as formulation variable. Characterization of the nanosupension was performed by measuring particle size, zeta potential, Fourier Transform infrared spectra (FTIR), Differential Scanning Calorimetry (DSC), Powder X-Ray Diffraction (PXRD), drug entrapment efficiency and in vitro release. In addition, freeze drying, redispersibility and short term stability study at room temperature and at 40C were performed. Results: Spherical, uniform particles (size below 500 nm) with positive zeta potential were obtained. No significant chemical interactions between drug and polymer were observed in the solid state characterization of the freeze dried nanosuspension (FDN). Drug entrapment efficiency of the selected batch was increased by changing the pH of the external phase and addition of polymethyl methacrylate in the formulation. The prepared nanosuspension exhibited good stability after storage at room temperature and at 40C. Sucrose and Mannitol were used as cryoprotectants and exhibited good water redispersibility of the FDN. Conclusion: The results indicate that the formulation of sulfacetamide in Eudragit® RL100 nanosuspension could be utilized as potential delivery system for treating ocular bacterial infections.

scholarly journals CHARACTERIZATION OF DRUGS ENCAPSULATED INTO MESOPOROUS SILICA

2019 ◽  
pp. 7-11
Author(s):  
ARIF BUDIMAN
Keyword(s):  
Water Solubility ◽  
Drug Loading ◽  
Physicochemical Characterization ◽  
Amorphous State ◽  
Molecular State ◽  
Water Soluble ◽  
Crystal Nucleation ◽  
Formulation Development ◽  
Scanning Calorimetry

Solubility of the drug has a strong influence to achieve higher bioavailability of the drug in systemic circulation. More than 70% NCEs (new chemical entities) are hydrophobic, and practically difficult into solid formulation due to their poor water solubility. Mesoporous silicas (MSP) have been used for drug delivery system, especially for poorly water-soluble drugs. Encapsulation and interaction of drugs in MSP can enhance the delivery and maintain the stability of the drug. However, the characterization of the drug in MSP is necessary to confirm its molecular state. In this review, we present an overview of reports related to the characterization of drug encapsulated into MSP. Encapsulation of drugs in MSP can prevent recrystallization of drugs due to its inhibition of crystal nucleation. A porous material in MSP can maintain the drug in a physically stable amorphous state. The preventing of drug crystallization in MSP can enhance the solubility and the dissolution rate of drug. Therefore, in this work, attempts have been made to understand the molecular state of the drug in MSP. The physicochemical characterization of drug by transmission electron microscopy (TEM), scanning electron microscope (SEM), differential scanning calorimetry (DSC), fourier-transform infrared spectroscopy (FTIR), powder x-ray diffraction (PXRD) and thermogravimetric analysis (TGA) were discussed. The effect of solvent and methods of drug loading and the effect of the shape of MSP on release profiles are also presented. Overall, this review provides information about the characterization of drug encapsulated into MSP which will be useful in pharmaceutical formulation development.

scholarly journals Chemical Characterization of Specific Micropollutants from Textile Industry Effluents in Fez City, Morocco

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Hakima Talouizte ◽  
Mohammed Merzouki ◽  
Mohammed Benlemlih ◽  
Mohammed Bendriss Amraoui
Keyword(s):  
Carboxylic Acids ◽  
Organic Compounds ◽  
Textile Industry ◽  
Physicochemical Characterization ◽  
Chemical Characterization ◽  
Environment Impact ◽  
Textile Effluents ◽  
Discharge Water ◽  
Wide Range

Textile industry is one of the most polluting industries in the world. It has a high importance in terms of its environment impact, since it consumes a considerably large amount of water and produces highly polluted discharge water. In this work, characterization of toxic organic compounds is proposed. Based on gas chromatography coupled to mass spectrometry (GC/MS) screening analysis, organic micropollutant diversity of textile effluents from a local textile processing factory was investigated. In the present work, physicochemical characterization of the studied textile effluents showed considerably high values of principal pollution parameters above the prescribed discharge water limits. Heavy metals like zinc (Zn), copper (Cu), iron (Fe), nickel (Ni), cadmium (Cd), chromium (Cr), and lead (Pb) were found to be present within the permissible limits. The results of GC/MS revealed the presence of various organic compounds belonging to a wide range of chemical classes. Main groups of chemical compounds detected in these effluents were aromatic carboxylic acids, alkanes, aromatic amines, phthalates, aliphatic carboxylic acids, and linear aliphatic alcohols. The results of this study allowed significant contributions to the chemical characterization of textile industry contaminants and identification of indicators that can be considered an important tool for assessment of the potential impact of textile activities to the contamination of aquatic environment and health hazard.

scholarly journals Solid-State Characterization of Different Crystalline Forms of Sitagliptin

Materials ◽  
2019 ◽  
Vol 12 (15) ◽  
pp. 2351 ◽  
Author(s):  
Nayana C. F. Stofella ◽  
Andressa Veiga ◽  
Laiane J. Oliveira ◽  
Elisa F. Montin ◽  
Itamar F. Andreazza ◽  
...  
Keyword(s):  
Solid State ◽  
Melting Point ◽  
Physicochemical Characterization ◽  
Spectroscopic Techniques ◽  
Scanning Calorimetry ◽  
Pharmaceutical Dosage Form ◽  
Base Form ◽  
Crystalline Forms ◽  
Solid State Characterization

Sitagliptin is an inhibitor of the enzyme dipeptidyl peptidase-4, used for the treatment of type 2 diabetes mellitus. The crystal structure of active pharmaceutical solids determines their physical and chemical properties. The polymorphism, solvates and hydrates can influence the free energy, thermodynamic parameters, solubility, solid-state stability, processability and dissolution rate, besides directly affecting the bioavailability. Thus, the physicochemical characterization of an active pharmaceutical ingredient is required to guarantee the rational development of new dosage forms. In this context, we describe herein the solid-state characterization of three crystalline forms of sitagliptin: sitagliptin phosphate monohydrate, sitagliptin phosphate anhydrous and sitagliptin base form. The investigation was carried out using differential scanning calorimetry (DSC), thermogravimetry (TG)/derivative thermogravimetry (DTG), spectroscopic techniques, X-ray powder diffraction (XRPD) and morphological analysis by scanning electron microscopy. The thermal analysis revealed that during the dehydration of sitagliptin phosphate monohydrate (Tpeak = 134.43 °C, ΔH = −1.15 J g−1) there is a characteristic crystalline transition event, which alters the physicochemical parameters of the drug, such as the melting point and solubility. The crystalline behavior of sitagliptin base form differs from that of sitagliptin phosphate monohydrate and sitagliptin phosphate anhydrous, mainly with regard to the lower temperature of the fusion event. The melting point (Tpeak) values obtained were 120.29 °C for sitagliptin base form, 206.37 °C for sitagliptin phosphate monohydrate and 214.92 °C for sitagliptin phosphate anhydrous. In relation to the thermal stability, sitagliptin phosphate monohydrate and sitagliptin phosphate anhydrous showed a slight difference; however, both are more thermostable than the base molecule. Therefore, through this study it was possible to establish the most suitable crystalline form of sitagliptin for the development of a safe, effective and appropriate pharmaceutical dosage form.

Physicochemical Characterization of the Inclusion Complex of Diosmetin with Hydroxypropyl-β-Cyclodextrin

2013 ◽  
Vol 295-298 ◽  
pp. 298-302
Author(s):  
Yan Zhang ◽  
Korbanjhon Brad
Keyword(s):  
Differential Scanning Calorimetry ◽  
Inclusion Complex ◽  
Physicochemical Properties ◽  
Water Solubility ◽  
Physicochemical Characterization ◽  
Infrared Spectrometry ◽  
Scanning Calorimetry ◽  
Covalent Bonds ◽  
X Ray

In this study, the inclusion complex of diosmetin with hydroxypropyl-β- -cyclodextrin (HP-β-CD) was prepared to improve the water solubility of diosmetin by the solvent method. The content of diosmetin in the complex was determined by UV. And the physicochemical properties of the complex were analyzed by ultraviolet-visible spectrometry (UV), infrared spectrometry (IR), X-ray diffractometry (XRD), differential scanning calorimetry (DSC). The results showed that the physical phase of diosmetin had been changed. It was completely dispersed in HP-β-CD. HP-β-CD and diosmetin were combined by non-covalent bonds.

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