Photophysical, electro- and spectroelectro-chemical properties of the nonplanar porphyrin [ZnOEP(Py)44+,4Cl−] in aqueous media

2010 ◽  
Vol 213 (1) ◽  
pp. 52-60 ◽  
Author(s):  
N. Karakostas ◽  
D. Schaming ◽  
S. Sorgues ◽  
S. Lobstein ◽  
J.-P. Gisselbrecht ◽  
...  
Keyword(s):  
Aqueous Media ◽  
Chemical Properties

An overview of Natural Superdisintegrants

2021 ◽  
pp. 113-124
Author(s):  
Shushank Sharma
Keyword(s):  
Gastrointestinal Tract ◽  
Aqueous Media ◽  
Chemical Properties ◽  
Cost Effective ◽  
Oral Route ◽  
Drug Formulation ◽  
Release Time ◽  
Disintegration Time ◽  
Physico Chemical ◽  
Set Up

The oral route is the most convenient route of administration for various drugs. It is viewed as the most convenient, most secure, and economical route for patients. Fast disintegrating tablets are popular these days as they disintegrate in the mouth within a few seconds without the use of water. The burdens of regularly used medications in pediatric and geriatric patients have been overwhelmed by quick-dissolving tablets. Natural superdisintegrants have been used for fast-dissolving tablets because they are biodegradable, chemically inert, non-harmful, more affordable, and generally accessible. Natural polymer improves the properties of the tablet as it is commonly used as diluents and binders. Natural super disintegrants decrease the release time and give healthful results to the patients. Most polymers are obtained from nature, they are cost-effective, non-toxic, and non-irritants. Disintegration is the most important step for releasing the drug from the tablet matrix to decrease the disintegration time. In this, drug and polymers come in contact with water, it swells, hydrate, and react chemically to release the drug in the mouth and gastrointestinal tract. Superdisintegrants are those substances that encourage the quick breaking down with a lesser amount contrasted with disintegrants. The quick disintegrants tablets are set up by utilizing suitable polymers which rely on the Physico-chemical properties of drugs and excipients, for example, drug and polymer compatibility, hardness and thickness of tablet, nature of drug and excipients, PH of drug and release parameters of drug formulation. Superdisintegrants are the vehicles added to tablet formulation to advance the breaking of tablets and capsules into small microparticles in aqueous media resulting in to increase in the surface area and promote quick drug release. The disintegrants have a significant capacity to oppose the efficacy of tablet binders and compression forces to form the tablet. Commonly there are three methods to incorporate disintegrants into the tablet: A. Inner addition, B. External expansion, C. Internal, and external addition. Most of the regularly based tablets are those expected to be swallow, disintegrate and release medicaments in the gastrointestinal tract but over a while tablets are manufactured to deliver medicaments in the mouth and gastrointestinal tract within few seconds of swallowing. It has been demonstrated that characteristic polymers are more effective than synthetic polymers. Some research is going to develop safe and effective medication with super disintegrating agents that can be dissolved rapidly to treat the disease.

scholarly journals Application of Amberlite IRA 402 Resin Adsorption and Laccase Treatment for Acid Blue 113 Removal from Aqueous Media

Polymers ◽  
2021 ◽  
Vol 13 (22) ◽  
pp. 3991
Author(s):  
Nicoleta Mirela Marin ◽  
Ioana Stanculescu
Keyword(s):  
Exchange Process ◽  
Aqueous Media ◽  
Chemical Properties ◽  
Environmentally Friendly ◽  
Degradation Process ◽  
Maximum Adsorption Capacity ◽  
Residual Concentration ◽  
Physical Chemical ◽  
Acid Blue 113 ◽  
Acid Blue

Despite Acid Blue 113 (AB 113)’s extensive use and negative environmental impact, very few studies have focused on its efficient and environmentally friendly removal. This research aims the removal of AB 113 from environmental aqueous media and its consequent enzymatic biodegradation. A strongly basic anion exchange resin in Cl− form, Amberlite IRA 402 (IRA 402(Cl−)) was used for AB 113 adsorption and a laccase was used to further biodegrade it. For the first time, two novel, efficient and environmentally friendly physical–chemical and biological assays for AB 113 wastewater removal and subsequent biodegradation were combined. The adsorption of AB 113 onto IRA 402(Cl−) was tested in batch and continuous flux modes. Influence of contact time, concentration and desorption in acidic media were evaluated. The kinetic data were best modulated by the Lagergren model with R2 = 0.9275. The Langmuir isotherm model best fitted the experimental data, and the maximum adsorption capacity was 130 mg/g. Dye, resin and AB113 loaded resin were characterized by thermogravimetry and FTIR to evaluate their physical chemical properties modification. Based on the performed studies, a consecutive methodology is proposed, incorporating the ion exchange process in the first stage and the biodegradation process in the second. Thus, in the second stage the residual concentration of AB 113 is reduced by an efficient bio-degradation process produced by the laccase at pH = 4.

scholarly journals Supramolecular Structures and Self-Association Processes in Polymer Systems

2016 ◽  
pp. S165-S178 ◽  
Author(s):  
M. HRUBÝ ◽  
S. K. FILIPPOV ◽  
P. ŠTĚPÁNEK
Keyword(s):  
Self Assembly ◽  
Targeted Delivery ◽  
Aqueous Media ◽  
Polymer System ◽  
Chemical Properties ◽  
Building Blocks ◽  
Self Organization ◽  
Triggered Release ◽  
Polymer Systems ◽  
Self Association

Self-organization in a polymer system appears when a balance is achieved between long-range repulsive and short-range attractive forces between the chemically different building blocks. Block copolymers forming supramolecular assemblies in aqueous media represent materials which are extremely useful for the construction of drug delivery systems especially for cancer applications. Such formulations suppress unwanted physico-chemical properties of the encapsulated drugs, modify biodistribution of the drugs towards targeted delivery into tissue of interest and allow triggered release of the active cargo. In this review, we focus on general principles of polymer self-organization in solution, phase separation in polymer systems (driven by external stimuli, especially by changes in temperature, pH, solvent change and light) and on effects of copolymer architecture on the self-assembly process.

Solubilization, characterization, and protein coupling analysis to multiwalled carbon nanotubes

2020 ◽  
pp. 095400832095803
Author(s):  
Juliane Glória ◽  
Walter Brito ◽  
Ariamna Gandarilla ◽  
Duniesky Larrude ◽  
Jacqueline Carlos ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Multiwalled Carbon Nanotubes ◽  
Aqueous Media ◽  
Chemical Properties ◽  
Electron Microscopic ◽  
Multiwalled Carbon ◽  
Physical And Chemical ◽  
The Impact ◽  
Microscopic Techniques ◽  
And Chemical Properties

Since their discovery, carbon nanotubes were used for numerous applications in the most diverse knowledge areas. However, the lack of solubility of these molecules in aqueous media compromises their beneficial properties for certain applications. Several methods to solubilize carbon nanotubes are described, however, depending on the intended application, the impact that the solubilization has on the physical and chemical properties needs to be considered. In the present study, a simple methodology is described that utilizes polyvinylpyrrolidone combined with sonication and centrifugation to solubilize multiwalled carbon nanotubes. Proteins were coupled to the surface of the solubilized products and characterized using various spectroscopic and electron microscopic techniques, evaluating the characteristics and integrity of the nanoparticle after the process. It was successfully demonstrated that nanotubes can be solubilized through a simple technique, without compromising their chemical characteristics, which makes them suitable materials for use in biomedical applications, due to their biocompatibility and lack of toxicity, among others.

Ag/CdS Nanocomposite: An Efficient Recyclable Catalyst for the Synthesis of Novel 8-Aryl-8H-[1,3]dioxolo[4,5-g]chromene-6-carboxylic Acids under Mild Reaction Conditions

2018 ◽  
Vol 21 (5) ◽  
pp. 323-328 ◽  
Author(s):  
Shahrzad Abdolmohammadi ◽  
Seyed Reza Rasouli Nasrabadi ◽  
Ahmad Seif ◽  
Narges Elmi Fard
Keyword(s):  
Carboxylic Acids ◽  
Condensation Reaction ◽  
Sol Gel ◽  
Aqueous Media ◽  
Chemical Properties ◽  
Catalytic Amount ◽  
13C Nmr Spectroscopy ◽  
Biological Properties ◽  
Recyclable Catalyst ◽  
Reaction Conditions

Aim and Objective: Chromene derivatives are privileged heterocyclic systems that exhibit various types of biological properties such as antioxidant, anticancer, antimicrobial, hypotensive, and local anesthetic. Cadmium sulfide nanoparticles (CdS NPs) as an efficient heterogeneous catalyst is used in various organic transformations because of its certain unique and unusual physico-chemical properties. The effectiveness of catalytic activity of CdS NPs can be improved due to the combined effect of Ag particles. Results: Ag/CdS nanocomposite is a readily available, recyclable, and non-toxic catalyst used for the highly efficient synthesis of novel 8-aryl-8H-[1,3]dioxolo[4,5-g]chromrne-6-carboxylic acids. This reaction is conveniently performed under mild reaction conditions. All synthesized compounds were well characterized by their satisfactory elemental analyses, IR, 1H and 13C NMR spectroscopy. The synthesized catalyst was fully characterized by XRD, SEM, and EDX techniques. Materials and Methods: The present methodology focuses on the condensation reaction of arylmethylidenepyruvic acids with 3,4-methylenedioxyphenol, using a catalytic amount of Ag/CdS nanocomposite (15 mol%) in aqueous media at room temperature to afford 8-aryl-8H-[1,3]dioxolo [4,5-g]chromrne-6-carboxylic acids in high yields (90-97%) within short reaction times (2-4 h). The Ag/CdS nanocomposite was also prepared by an ultrasonic-assisted sol-gel method. Conclusion: In conclusion, we have successfully synthesized novel 8-aryl-8H-[1,3]dioxolo[4,5- g]chromrne-6-carboxylic acid derivatives by the Ag/CdS nanocomposite catalyzed cyclocondensation reaction of arylmethylidenepyruvic acids with 3,4-methylenedioxyphenol under mild reaction conditions. Environmentally benign procedure, high to excellent yields of products, simplicity of operation, and use of readily available and recyclable catalyst are the advantages of this new practical reaction.

A review: An overview of Natural Superdisintegrants

2021 ◽  
pp. 13-24
Author(s):  
Shushank Sharma ◽  
Sikha Chauhan
Keyword(s):  
Gastrointestinal Tract ◽  
Aqueous Media ◽  
Chemical Properties ◽  
Cost Effective ◽  
Oral Route ◽  
Drug Formulation ◽  
Release Time ◽  
Disintegration Time ◽  
Physico Chemical ◽  
Set Up

The oral route is the most convenient route of administration for various drugs. It is viewed as the most convenient, most secure, and economical route for patients. Fast disintegrating tablets are popular these days as they disintegrate in the mouth within a few seconds without the use of water. The burdens of regularly used medications in pediatric and geriatric patients have been overwhelmed by quick-dissolving tablets. Natural superdisintegrants have been used for fast-dissolving tablets because they are biodegradable, chemically inert, non-harmful, more affordable, and generally accessible. Natural polymer improves the properties of the tablet as it is commonly used as diluents and binders. Natural super disintegrants decrease the release time and give healthful results to the patients. Most polymers are obtained from nature, they are cost-effective, non-toxic, and non-irritants. Disintegration is the most important step for releasing the drug from the tablet matrix to decrease the disintegration time. In this, drug and polymers come in contact with water, it swells, hydrate, and react chemically to release the drug in the mouth and gastrointestinal tract. Superdisintegrants are those substances that encourage the quick breaking down with a lesser amount contrasted with disintegrants. The quick disintegrants tablets are set up by utilizing suitable polymers which rely on the Physico-Chemical properties of drugs and excipients, for example, drug and polymer compatibility, hardness and thickness of tablet, nature of drug and excipients, PH of drug and release parameters of drug formulation. Superdisintegrants are the vehicles added to tablet formulation to advance the breaking of tablets and capsules into small microparticles in aqueous media resulting in to increase in the surface area and promote quick drug release. The disintegrants have a significant capacity to oppose the efficacy of tablet binders and compression forces to form the tablet. Commonly there are three methods to incorporate disintegrants into the tablet: A. Inner addition, B. External expansion, C. Internal, and external addition. Most of the regularly based tablets are those expected to be swallow, disintegrate and release medicaments in the gastrointestinal tract but over a while tablets are manufactured to deliver medicaments in the mouth and gastrointestinal tract within few seconds of swallowing. It has been demonstrated that characteristic polymers are more effective than synthetic polymers. Some research is going to develop safe and effective medication with super disintegrating agents that can be dissolved rapidly to treat the disease.

scholarly journals IMMOBILIZATION OF COBALT DISULFOPHTHALOCYANINATE ONTO POLYMETHYLOLACRYLAMIDE

2018 ◽  
Vol 61 (8) ◽  
pp. 73
Author(s):  
Galina V. Osipova ◽  
Nadezhda L. Pechnikova ◽  
Tatiana A. Ageeva
Keyword(s):  
Metal Complex ◽  
Water Solubility ◽  
Electronic Absorption Spectra ◽  
Aqueous Media ◽  
Three Dimensional ◽  
Chemical Properties ◽  
Water Soluble ◽  
Water Soluble Polymer ◽  
One Step ◽  
Insoluble Compounds

Different character of usage the porphyrins and their analogs immobilized on carrier polymers stimulates an increased interest in the synthesis and research of physico-chemical properties of porphyrin-polymer immobilizates. In this paper the peculiarities of a synthesis of water-soluble polymer systems containing cobalt disulfophthalocyaninate with the components of a different ratio are described. The methylolation reaction of polyacrylamide to immobilize cobalt disulfophthalocyaninate onto water-soluble carrier polymer has been carried out. It is known that heating polymethylolacrylamide or its solutions leads to the formation of three-dimensional structures with ether and methylene bridges. Therefore, initially the conditions for the preparation of polymethylolacrylamide with preservation of its water solubility were selected. It was found to obtain a water-soluble polymethylolacrylamide, it is necessary that the initial concentration of polyacrylamide in water did not exceed 2% by weight. The immobilization of phthalocyanine metal complex onto the modified polyacrylamide was carried out in two ways. The first is the interaction of the phthalocyanine metal complex with methylated polyacrylamide. The second is functionalization of polyacrylamide and the immobilization of phthalocyaninate metal complex onto the polymer in one-step. The introduction conditions of the cobalt disulfophthalocyaninate introduced influenced the formation of cross-linked structures in the synthesized samples. The introduction of macroheterocycle as a powder was found to promote the formation of insoluble compounds in aqueous media. Therefore, phthalocyanine metal complex was introduced into the system as 1% aqueous solution. The immobilization of the phthalocyanine metal complex onto a carrier polymer has been realized through the formation of hydrogen bonds between the methylol groups of polymethylolacrylamide and sulfo groups of the phthalocyanine metal complex and it was due to coordination interaction between the functional groups of the polymer and metallophthalocyanine as well. The amount of bound cobalt disulfophthalocyanine in the samples was determined by the electronic absorption spectra of the solutions of immobilized phthalocyanine metal complex onto the polymer. The mass content of immobilized cobalt disulfophthalocyaninate onto the polymer in the samples obtained by one-step is greater than in case of the samples obtained in two steps, the ratio of the initial reagents being the same.

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