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pH dependent hydrogels of modified tamarind kernel polysaccharide (TKP) were synthesized by grafting with polyacrylamide chains on TKP backbone in presence of microwave irradiation and initiator. The present study is carried out to design oral controlled drug delivery systems for aspirin using synthesized hydrogels as carrier in form of tablets. TKP-g-PAM based hydrogels show significant enhancement for control release of aspirin. Release behavior of aspirin has been evaluated using USP type I apparatus in 900 mL of buffer solutions (pH 1.2, 6.8, 7.4), maintained at 37°C at 100 rpm. It is observed that with increase in percentage of grafting (% G), swelling of matrices increases whereas erosion and rate of drug release decrease. The effect of % G onto t50 value (time taken for release of 50% drug) has also been discussed. The release characteristics from the matrices under study show non-Fickian diffusion mechanism, suggesting the controlled release of aspirin., (Copyright © 2013 Elsevier B.V. All rights reserved.)

A novel hybrid nanocomposite has been prepared using in situ incorporation of nano-sized filler (silica) onto carboxymethyl tamarind kernel polysaccharide (CMT). Various characterizations were employed to confirm that silica nano particles have been incorporated onto the polymer matrix. Rheological characteristics reveal stronger CMT-Si interaction at 0.5 and 1 wt% level. Beyond 1 wt% Si concentration, the interaction is less and so there is little drop in shear viscosity. Flocculation efficiency increases with incorporation of nano filler, maximum efficacy being observed at 1 wt% silica concentration. All the nanocomposites exhibited better flocculation characteristics in comparison to pure CMT., (Copyright © 2011 Elsevier B.V. All rights reserved.)

A high performance anionic flocculant was synthesized by partial alkaline hydrolysis of polyacrylamide grafted tamarind kernel polysaccharide. Various macromolecular characterizations were employed to confirm that partial alkaline hydrolysis of grafted polyacrylamide chains does take place. The flocculation characteristics of the hydrolyzed and unhydrolyzed grafted products were carried out in kaolin suspension and municipal sewage wastewater and it has been found that hydrolyzed product outperforms the unhydrolyzed grafted TKP., (Copyright © 2010 Elsevier Ltd. All rights reserved.)

Novel biodegradable polymeric flocculants were produced by conventional redox grafting, microwave-initiated and microwave-assisted grafting of acrylamide to tamarind kernel polysaccharide (TKP). The graft copolymers were characterized by viscometry, elemental analysis, molecular weight determination using SLS analysis, and NMR spectroscopy. The flocculation efficiency of the grafting products in kaolin suspension, municipal sewage wastewater and textile industry wastewater was primarily dependent on the length of the grafted polyacrylamide chain. The flocculant obtained by microwave-assisted grafting method was superior to TKP and polyacrylamide-based commercial flocculant (Rishfloc 226 LV) in flocculation tests., (Copyright (c) 2010 Elsevier Ltd. All rights reserved.)

Synthesis of cationic tamarind kernel polysaccharide (Cat TKP), its detailed physicochemical characterization and application as an efficient flocculant for the treatment of textile industry wastewater have been investigated. N-3-Chloro-2-hydroxypropyl trimethyl ammonium chloride (CHPTAC) was used as a cationic reagent to introduce quaternary amine groups onto the backbone of tamarind kernel polysaccharide (TKP). Various grades were synthesized to obtain the optimized one. Effect of reaction parameters onto the degree of cationization has also been investigated. The synthesized polymers were characterized by various macromolecular characterization techniques, which confirm that cationization does take place. Afterwards, the applicability of TKP and various grades of Cat TKP's as flocculants for the treatment of textile industry wastewater was investigated. The flocculation experiments showed that TKP alone contributes little to the flocculation. However, cationic TKP led to significant improvement as flocculant for the treatment of textile industry wastewater. The best performing Cat TKP (i.e. Cat TKP 3) was thereafter compared with a commercial flocculant, which is cationic in nature. It has been observed that Cat TKP 3 surpasses the flocculation efficiency over commercial flocculant.

The development of amphiphiles for sustained drug delivery represents a promising approach in biomedical fields. Polymeric self‐assembly with a hydrophobic core offers plenty of opportunities to encapsulate hydrophobic drugs for facilitating targeted delivery to the specific sites of action. Herein, N‐Boc tryptophan has been used to develop a hydrophobic monomer, Boc‐tryptophan‐HEMA (HBT). The HBT monomer has further been grafted on modified alginic acid through the RAFT technique to synthesize a unique amphiphilic copolymer with fluorescence characteristics. The advanced polymer chromatography demonstrates a narrow distribution curve, signifying the living nature of polymerization. The copolymer has exhibited self‐aggregation behavior with two distinct shapes at two different critical aggregation concentrations (CAC). The concentration‐dependent shape variation has been investigated using FESEM and TEM analyses, further supported by a small‐angle x‐ray scattering analysis. The self‐aggregation behavior of the copolymer facilitates the uptake of a model hydrophobic drug (naproxen) and its release in a sustained manner with varied rates at two different concentrations. [ABSTRACT FROM AUTHOR]

RAFT polymerization is a well‐known approach to develop amphiphilic copolymer with less heterogeneity and narrow dispersity. Herein, an amphiphilic bioconjugated graft‐block copolymer (Dextran‐g‐(PNIPAAm‐b‐PVAc)) using dextran, N‐isopropyl acrylamide and vinyl acetate has been developed through RAFT polymerization. The chain length of the PVAc block has been varied to obtain the copolymers with different hydrophobic segments. The lower critical solution temperature, critical micelle concentration, and micellar stability of the synthesized copolymers have been studied in details. in‐vitro cytotoxicity, as well as the in vitro release of a hydrophobic drug have been carried out to explore its suitability in the field of biomedical science. The synthesized copolymer has been found to have controlled molecular weight with narrow dispersity. It is cytocompatible toward Human cervical cancer cell line cell lines, can efficiently load a hydrophobic drug‐norfloxacin, and subsequently, release in the sustained manner as manifested from in vitro release study. [ABSTRACT FROM AUTHOR]

Many of the synthetic corrosion inhibitors being used currently, are toxic and therefore research for developing environmentally benign corrosion inhibitors is of great importance. Inhibitors such as natural polysaccharides of plant origin are popular due to its non-toxic nature. Here, the toxicity of a natural polysaccharide, guar gum, and its modified form, cationic guar gum was studied and their inhibitory effects were investigated by gravimetric, electrochemical and surface morphology studies. Both the inhibitors are found to be effective and their adsorption on metal is in accordance with the Langmuir adsorption isotherm. Experimental results are in consonance with the results of quantum chemical calculations by density functional theory. [ABSTRACT FROM PUBLISHER]

A new class of biodegradable crosslinked hydrogel, consisting of hydrophobic polylactic acid (PLA) and hydrophilic dextrin in presence of crosslinker N, N-methylene bisacrylamide (MBA) has been synthesized by free-radical polymerization technique using potassium persulfate (KPS) as initiator. By variation of crosslinker concentration, a series of hydrogels have been prepared and the optimized grade has been selected on the basis of higher crosslinking efficiency as well as lower equilibrium swelling characteristics, XRD analysis. The hydrogels have been characterized by FTIR spectra, 13C-NMR spectra, CHN analysis, SEM analysis, swelling characteristics, and toxicity study. In vitro release study of model drugs (ciprofloxacin and ornidazole) from hydrogel matrix has been performed in various buffer solutions at 37°C. The drug release kinetics and mechanism have been studied using zero order, first-order kinetic models, Korsemeyar-Peppas model, Higuchi model, Hixson-Crowell model, and nonlinear Kopcha model. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40039. [ABSTRACT FROM AUTHOR]

The article discusses a study which examined the sustained release behavior of acetylsalicylic acid from carboxymethylstarch (CMS) based matrix. Particular focus is given to the preparation of CMS by incorporating carboxymethyl groups in the starch moiety. Results of the study showed an increase in the rate of drug release as pH value rises. Findings also revealed that a combination of tablet erosion and diffusion of the drug have controlled the release.

Polysaccharides are abundantly available from farm, forest, and microbial resources. They are used in myriad applications. It has been established in the authors' laboratory that their performance is enhanced considerably on purification, grafting by polyacrylamide (PAM), and subsequent hydrolysis as well as cationization. The most significant performance is enhanced in flocculation where it has been found that the modified polysaccharides outperform existing flocculants in national and international markets. Similar effects are observed in their performance in turbulent drag reduction (DR), percolation, and rheology. The present article outlines the details of materials, mechanisms, and practical applications of these novel materials. [ABSTRACT FROM AUTHOR]

Abstract: Five polysaccharides namely amylopectin, amylose, glycogen, guar gum and starch have been cationized by grafting with N-(3-chloro-2-hydroxypropyl) trimethyl ammonium chloride and studied for their flocculation behaviors. Of them, cationic glycogen (Cat Gly) is found to be the best for flocculation of coal suspended sample amongst cationic polysaccharides. Cat Gly was compared with some of the commercial flocculants. [Copyright &y& Elsevier]

The article discusses a study which examined the synthesis of carboxymethylated tamarind (CMT) by reacting tamarind kernel powder (TKP) with sodium salt of monochloro acetic acid in the presence of sodium hydroxide. A variety of materials characterization methods were used to characterize the new material. Results of the study showed that the intrinsic viscosity of CMT was greater compared to that of TKP. It also found that CMT has a higher oxygen percentage than TKP.

The article discusses research done on the characterization of cationic starch as a flocculating agent. Starch is a carbohydrate consisting of amylopectin and amylose. A modified cationic starch can be developed by inserting a cationic moiety to the backbone of starch. Various techniques were used to characterize cationic starch, starch, and base polysaccharide.

Abstract: The phenomenon of flocculation in liquid suspensions has a variety of applications, including mineral processing, treatment of industrial effluents, and municipal sewage sludge purification. Obtaining metals from ores would not be possible without the slurry processing route. Flocculants play here a double role: limiting environmental contamination and also slowing down depletion of raw materials — including potable, industrial and agricultural water. Development of better flocculants requires improved understanding of the mechanism of their action. We propose a model of flocculation based on the assumption that effective flocculants pervade large volumes of liquids in the suspensions. Since many flocculants are polymers, good flocculants according to the model should have large radii of gyration R G. We therefore assume a connection between R G and settling velocities y of particles out of suspension. Four different types of aqueous suspensions are studied, containing in turn silica, coal, Mn ore and Fe ore. A unique relationship is demonstrated between R G and y for several polymeric flocculants in each type of slurry. For each suspension type the corresponding equation has the form y = aR G b , where the two parameters characterize the suspended particles and the liquid medium. While polysaccharides from natural sources are used as flocculants, we show how their cationization enhances the flocculation efficiency in all media we have studied. Large effects are achieved for the flocculating agent concentrations in the range of 6–9 ppm. [Copyright &y& Elsevier]

An abstract of the article "Investigation on Flocculation Characteristics of Cationic Polysaccharides: Novel Polymeric Flocculants" by Sagar Pal and Ram P Singh is presented.