Carboxymethyl Guar Research Articles

Carboxymethylguargum-silver nanocomposite: green synthesis, characterization and an optical sensor for ammonia detection

This work describes the preparation of new carboxymethyl guar gum-silver nanocomposite (CMGG/Ag NC) by green synthesis method. For this carboxymethyl guar gum was used as a reducing agent as well as stabilizer. The silver nanoparticles obtained were characterized by field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), UV–vis spectroscopy, Fourier transform infrared (FTIR) and energy dispersive x-ray analysis (EDX). The average size of the silver nanoparticles was found of ∼6 nm. Thus, the obtained CMGG/AgNPs NC was examined for optical sensing property for detection of ammonia in aqueous medium. The response time and the detection limit of ammonia in aqueous solution were detected at room temperature. It was concluded that in the future, at this room temperature optical ammonia sensor may be used for medical diagnosis and clinically for detecting low ammonia level (up to 1 ppm) in biological samples for various biomedical applications.

Encapsulation of Congo Red in carboxymethyl guar gum–alginate gel microspheres

Congo Red (CR) is a hydrophobic dye commonly used for diagnosis and potentially useful as therapeutic agent of beta amyloid plaques in neurodegenerative diseases. CR, as drug model, was encapsulated on Alginate–Carboxy Methyl Guar Gum (Alg–CMGG) blend microspheres. Guar gum 18% carboxymethylated (CMGG) derivative was synthesized in order to improve aqueous solubility, polymer blending and help reduce surface tension. The derivative was confirmed by FTIR spectroscopy, and elemental analysis. Surface tension of the new CMGG is reduced in about 50% compared with the native polymer. Lowering of Guar Gum (GG) aqueous solutions viscosity from 30,000cps to 350–400cps in case of CMGG is indicating pseudoplastic fluid behavior modifications. Vibrational spectroscopy analysis confirmed interactions among CR molecules in alginate–CMGG matrices ascribed largely to the aromatic motif of the dye and the biopolymer a polar regions. CR was encapsulated on 68/32% alginate/CMGG blend microspheres as the best formulation tested. The release of CR from the microspheres was not detected at pH=1.2 in 25min, but 62% of CR was found in the supernatant when the pH was raised to 7.4 at 37°C after 8h incubation.

Preparation and characterization of carboxymethyl guar gum nanoparticles

Carboxymethyl guar gum nanoparticles (CMGGNPs) were synthesized by nanoprecipitation and sonication method. This method was used for the first time for the synthesis of carboxymethyl guar gum nanoparticles. It was found that the formation of nanoparticles might depend upon the sonication time, solvent, and stirring time. Nanoparticles were characterized by SEM, TEM, XRD and FTIR. The sizes of the particles in suspension have been found in the range 12–30nm. It was concluded that such type of nanoparticles may be used in pharmaceutical and drug delivery.

Biodegradable polymeric microspheres of gelatin and carboxymethyl guar gum for controlled release of theophylline

Carboxymethyl guar gum (CMGG) was synthesized by carboxymethylation of guar gum (GG), which was blended with gelatin (GE) to obtain a novel semi-interpenetrating polymer network (semi-IPN) in the form of microspheres prepared by water-in-oil emulsion method to investigate the controlled release of theophylline (THP), an antiasthmatic drug. Electronic spectroscopy revealed the drug encapsulation ranging from 56 to 74 %. Fourier Transform infrared spectroscopy confirmed the carboxymethylation of GG as well as the semi-IPN structure of the blend polymer. Scanning electron microscopy indicated the smooth surfaces with spherical microspheres. Differential scanning calorimetric and X-ray diffraction studies showed the molecular level dispersion of drug in the microspheres. The in vitro drug release profiles were analyzed to study the effect of polymer blend composition, % drug loading and amount of glutaraldehyde added as a crosslinker. The drug release was extended up to 26 h. The in vitro release data performed in acidic and alkaline media were analyzed using the empirical equations to understand the release profiles of THP.

A REVIEW ON DERIVATIZATION OF GUAR AND STUDY OF PHARMACEUTICAL APPLICATIONS OF GUAR DERIVATIVES

Guar gum is a naturally occurring alternating co-polymer derived from the seeds of Cyamopsis tetragonoloba. Guar has high intrinsic viscosity but very poor interaction coefficient. Guar dispersions lose viscosity upon standing. Guar has been derivatized to hydroxyalkyl, alkali carboxyalkyl and quaternary ammonium guar. Derivatization of guar enhances solution stability, clarity of dispersion and resistance to microbial attack. Derivatives of guar have immense pharmaceutical and cosmetic applications. The present review focuses on the various methodologies available for effecting derivatization of guar and also covers the specific application case studies in pharmaceutical and cosmeceutical fields. The authors opine that guar derivatives such as hydroxypropyl guar, sodium carboxymethyl guar and cationic guar are the prominent ones and shall be accorded an official status.

A transdermal device from 2-hydroxyethyl methacrylate grafted carboxymethyl guar gum–multi-walled carbon nanotube composites

A hydrophobic and biocompatible transdermal device has been developed from 2-hydroxyethyl methacrylate (HEMA) grafted carnboxymethyl guar gum (CMG)-functionalized multi-walled carbon nanotube (MWCNT) in situ composite membranes. The developed composites may be used for sustained delivery of diclofenac sodium. Supreme matrix–MWCNT interaction at 0.5 and 1 wt% MWCNT concentrations induces excellent copolymer-adsorbed fibrillar orientation of MWCNT compared to that at 2 and 3 wt%. It successively leads to efficient encapsulation and more sustained release of the drug molecules at these compositions (65% vs. 17% at 1 wt%). Analyses show that the releases are dominated by the viscoelastic relaxation behavior (power law indices 0.75 and 0.80 and extremely high Deborah numbers) of the devices. Conversely, for the latter, the releases are comparatively less sustained and more swelling controlled (indices are 0.5 and 0.6 and low Deborah numbers). However, all devices have significantly increased the half life period of the drug molecules (2.5 h vs. 47 h at 1 wt%).

A nanocomposite of silver and thermo-associating polymer by a green route: a potential soft–hard material for controlled drug release

Major research efforts are continuously being made to look for alternative, environment friendly green chemicals for the synthesis of nanoparticles in place of conventional and hazardous reducing agents such as sodium borohydride and hydrazine. We report here on the synthesis and characterization of AgNPs using a thermo-associating polymer namely, carboxymethyl guar grafted poly(ethylene oxide-co-propylene oxide) [CMG-g-PEPO]. The polymer acts as both reducing agent as well as stabilizing/capping agent. The formation of AgNPs with polymer was confirmed by UV/Vis spectroscopy and the TEM images indicated the size of nanoparticles to be in the range of 10–20 nm. We also demonstrated the use of these nanoparticles in the controlled release of doxorubicin hydrochloride (Dox), an anticancer drug. The binding of Dox onto the polymer and AgNPs was investigated by XPS and Raman spectroscopy which indicates that a charge-transfer mechanism is operative between the Dox and polymer holding both the entities together. The first synthesis of AgNPs using non-toxic thermo-associating polymer and subsequent release of Dox with body temperature (37 °C) as a trigger is the highlight of the present work.

Evaluation of guar gum derivatives as gelling agents for microbial culture media

Guar gum, a galactomannan, has been reported to be an inexpensive substitute of agar for microbial culture media. However, its use is restricted probably because of (1) its highly viscous nature even at high temperatures, making dispensing of the media to Petri plates difficult and (2) lesser clarity of the guar gum gelled media than agar media due to impurities present in guar gum. To overcome these problems, three guar gum derivatives, carboxymethyl guar, carboxymethyl hydroxypropyl guar and hydroxypropyl guar, were tested as gelling agents for microbial growth and differentiation. These were also evaluated for their suitability for other routine microbiological methods, such as, enumeration, use of selective and differential media, and antibiotic sensitivity test. For evaluation purpose, growth and differentiation of eight fungi and eight bacteria grown on the media gelled with agar (1.5%), guar gum (4%) or one of the guar gum derivatives (4%), were compared. All fungi and bacteria exhibited normal growth and differentiation on all these media. Generally, growth of most of the fungi was better on guar gum derivatives gelled medium than on agar medium. The enumeration carried out for Serratia sp. and Pseudomonas aeruginosa by serial dilution and pour plate method yielded similar counts in all the treatments. Likewise, the selective succinate medium, specific for P. aeruginosa, did not allow growth of co-inoculated Bacillus sp. even if gelled with guar gum derivatives. The differential medium, Congo red mannitol agar could not differentiate between Agrobacterium tumefaciens and Rhizobium meliloti on color basis, if gelled with guar gum or any of its derivatives However, for antibiotic sensitivity tests for both Gram-positive and -negative bacteria, guar gum and its derivatives were as effective as agar.

Synthesis and characterization of carboxymethyl guar gum and rheological properties of its solutions

Carboxymethyl guar gum was synthesized with a simple dry and multi-step method for the first time as a product of the reaction of guar gum and monochloroacetic acid in the presence of sodium hydroxide. The influences of a variety of reaction parameters for degree of substitution were evaluated. The product was characterized by a variety of material characterization techniques. FTIR showed new bonds at 1618, 1424 and 1325cm−1 after carboxymethylation. SEM showed that the surface of guar gum particles was mostly ruptured. XRD revealed that guar gum crystallinity was reduced. The rheological properties of product pastes were studied using a rotational viscometer. The viscosity of products’ solution decreased with increasing temperature and increased with increasing concentration. With the increase of storage time, the viscosity increased at first, and then decreased. In addition, a shear thinning pseudoplastic behavior was observed at all concentrations, temperatures and storage times.

In vitro, in vivo evaluation of inter polymer complexes between carboxymethyl fenugreek gum and chitosan or carboxymethyl guar gum and chitosan for colon delivery of tamoxifen

ObjectiveTo develop colon targeted tamoxifen tablets employing interpolymer complexes (IPC) between carboxymethyl fenugreek gum (CMF) and chitosan (CH) or carboxymethyl guar gum (CMG) and CH. MethodsIPC between CMF and CH or CMG or CH was obtained as a result of reaction between negatively charged -COO− group of CMF or CMG and positively charged -NH3+ group of CH. These interactions were characterized by FTIR spectroscopy. The core tablets were coated with various ratios of CMF: CH and CMG: CH IPC solutions. The coated tablets were subjected to in vitro dissolution studies in the presence or absence rat cecal contents. The selected coated tablets were evaluated for their pharmacokinetic behavior by oral administration to rats. ResultsThe tablets coated with CMF: CH 40:60 and CMG: CH 50:50 were capable of protecting drug release in pH 1.2 (stomach) and pH 7.4 (small intestine) and releasing, respectively, 91% and 94% tamoxifen in pH 6.8 in the presence of rat cecal contents. The oral administration of these tablets to rats showed a tmax of 10 hrs as compared to 2 hrs in case of uncoated tablets. ConclusionsThe tablets coated with CMF-CH ratio of 40:60 or CMG-CH ratio of 50:50 were able to protect drug release in stomach and small intestine and deliver tamoxifen after the tablets reached colon.

Tailoring carboxymethyl guargum hydrogel with nanosilica for sustained transdermal release of diclofenac sodium

Abstract Carboxymethyl guar gum (CMG) was structurally tailored with aqueous-nanosilica sol for controlled transdermal release of diclofenac sodium. Nanosilica was administered in low to moderately high concentration range to synthesize various, novel CMG–silica hybrid nanocomposites. Spectroscopy together with thermogravimetry, morphology, swelling and rheological studies proved that 1 wt% nanosilica content was the best physical formulation. The drug release studies from different hydrogel nanocomposites exhibited slower release than neat CMG. 1 wt% nanosilica loaded hydrogel nanocomposite gave slowest but steady release profile among all other nanocomposites due to its highly viscous nature owing to most compact microstructure.

Polymer hydrogel from carboxymethyl guar gum and carbon nanotube for sustained trans-dermal release of diclofenac sodium

Novel carboxymethyl guar gum (CMG)-chemically modified multiwalled carbon nanotube (MCNT) hybrid hydrogels were synthesized at different MCNT levels as potential device for sustained trans-dermal release of diclofenac sodium. Spectroscopy together with morphology, thermogravimetry, and rheological studies proved relatively strong CMG–MCNT interaction at 0.5 and 1wt% levels of MCNT whereas de-wetting was increased with higher MCNT concentration. Drug encapsulation tendency increased with addition of MCNT; maximum entrapment was noticed at 1wt% MCNT level. Hydrogels containing 0.5, 1 and 3wt% MCNT exhibited slower trans-dermal release than neat CMG due to slightly higher gel viscosity and more drug entrapment. Slowest but steady release was obtained from 1wt% MCNT loaded hydrogel due to highest viscous resistance among all other hybrid nanocomposites.

Flocculation properties of polyacrylamide grafted carboxymethyl guar gum (CMG-g-PAM) synthesised by conventional and microwave assisted method

A novel polymeric flocculant based on polyacrylamide grafted carboxymethyl guar gum (CMG-g-PAM) has been synthesised by grafting polyacrylamide chains onto CMG backbone using conventional redox grafting and microwave assisted grafting methods. Under optimum grafting conditions, 82% and 96% grafting efficiencies have been observed in case of conventional and microwave assisted methods respectively. The optimum sample has been characterized using viscometry, spectroscopic analysis, elemental analysis, molecular weight and radius of gyration determination. The flocculation characteristics of grafted and ungrafted polysaccharides have been evaluated in kaolin suspension, municipal sewage wastewater and decolourization efficiency of a dye solution (methylene blue). It is evident from results that CMG-g-PAM synthesised by microwave assisted grafting method is showing best flocculation characteristics.

Microspheres of carboxymethyl guar gum for in vitro release of abacavir sulfate: Preparation and characterization

AbstractCarboxymethyl guar gum (CMGG), an anionic semisynthetic GG derivative, was synthesized by incorporating CM group into GG chain. Microspheres were prepared by loading abacavir sulfate (AS) using water‐in‐oil (w/o) emulsion method. Formulations were characterized by Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR), X‐ray diffraction (XRD), thermogravimetry (TGA), differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). In vitro release profiles of GG and CMGG loaded with AS performed in pH 1.2 as well as 7.4 buffer media at 37°C displayed the varying drug release profiles in stomach and intestinal conditions. Release of the drug was extended up to 28 h in both GG and CMGG matrices, but the burst release observed in case of GG matrix was reduced in the case of CMGG. The kinetics of in vitro release was analyzed using the empirical equations. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011

The Research of a New Purifying Agent on Synthesis and Performance

This paper synthesis a new purifying agent on a rapid semidry process, using a natural guar gum as basic material, which was carboxymethyl guar. The factors which affect degree of substitution (DS) of carboxymethyl guar, such as the reaction temperature, the reaction time, the consumption of chloroacetic acid, and the consumption of sodium hydroxide etc were studied. The best synthesis condition was concluded. The flocculating property of the produced purifying agent was studied. Then the experiment analysis the structure and thermal stability through IR and DTA. The experiment results showed that the turbidity ratio of the micro-polluted water was better than other purifying agents. The synthetic purifying agent should have potential applications in the wastewater market.

Synthesis and characterization of grafted carboxymethyl guar gum

AbstractGraft copolymers of carboxymethyl guar gum (CMGG) and polyacrylamide (PAM) have been synthesized by grafting polyacrylamide chains onto carboxymethyl guar gum backbone using a ceric‐ion‐induced solution polymerization technique. By varying the amount of initiator, three different grades of graft copolymers are synthesized. The characterization of graft copolymer is carried out by FTIR, NMR, intrinsic viscosity measurement, SEM, SLS, DTG, and rheology. A comparison of flocculation efficiency of CMGG and its graft copolymer shows that the graft copolymer exhibits better flocculation performance. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011

Investigations on chitosan-carboxymethyl guar gum complexes interpolymer complexes for colon delivery of fluticasone.

The present study was designed to formulate colon release tablets of fluticasone by employing cross linked chitosan (CH) and carboxymethyl guar gum (CMG) interpolymer complexes (IPC). Matrix tablets were prepared by wet granulation method using IPC as binder and coating agent. The IPC were characterized by Fourier transform infrared spectroscopy (FTIR). The uncoated and coated tablets were tested for their suitability as colon specific drug delivery system by in vitro dissolution studies. The coated tablets were evaluated for their pharmacodynamic performance after oral administration to TNBS induced ulcerative colitic rats. FTIR studies demonstrated that the IPC was formed through an electrostatic interaction between –COO− groups of CMG and –NH3+ groups of CH. Tablets formulated with 50:50 CH:CMG as binder and coated with the respective ratio of IPC was capable of protecting the drug release in stomach and small intestine and delivering the drug in the colon. Histopathology of the rat colon after oral administration of these IPC film coated tablets revealed significantly greater (p<0.05) reduction in TNBS-induced ulcerative colitis The study confirmed that selective delivery of fluticasone to the colon can be achieved using cross-linked CH and CMG polysaccharides. Keywords: Chitosan; Colonic delivery; Carboxymethyl guar gum; Cross-linking; Guar gum; Fluticasone

Cationic Liposome Colloidal Stability in the Presence of Guar Derivatives Suggests Depletion Interactions May be Operative in Artificial Tears

The colloidal stability of cationic 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP) liposomes was measured in the presence of guar, carboxymethyl guar, hydroxypropyl guar (HPG), and in mixtures of HPG with boric acid. Carboxymethyl guar induced DOTAP aggregation, presumably by bridging flocculation. The interaction with HPG-borate, an anionic polyelectrolyte with labile charge groups, depended on ionic strength. Without added salt, HPG-borate (pH 9.2) adsorbed on the liposomes and destabilized them. In contrast, in 0.1 M NaCl, HPG-borate did not adsorb onto the liposomes. HPG, HPG-borate, and guar induced depletion flocculation of the liposomes at high polymer concentration. Depletion flocculation may be an important mechanism when HPG is employed in artificial tear formulations.

Synthesis and characterization of thermo-sensitive graft copolymer of carboxymethyl guar and poly( N-isopropylacrylamide)

Thermo-responsive graft copolymers of carboxymethyl guar [CMG] and semitelechelic poly( N-isopropylacrylamide) [PNIPAm] were synthesized by coupling reaction between them using a water-soluble coupling agent namely, 1-(3-(dimethylamino) propyl)-3-ethyl carbodiimide hydrochloride [EDC]. The incorporation of PNIPAm into CMG was confirmed by FT-IR and NMR spectroscopy. The graft copolymers, CMG-g-PNIPAm showed enhanced viscosity as compared to the unmodified CMG in the semi-dilute regime. Due to the presence of a LCST side chains [PNIPAm], the graft copolymers exhibited thermo-responsive nature with respect to temperature which was investigated using pyrene fluorescence probe studies. Although the thermo-responsive property was observed, the thermo-thickening behavior was not seen in these polymers. The graft copolymers in the semi-dilute regime ( C p ≈ 10–20 g/L) showed viscoelastic properties and the relaxation time, τ, could be obtained from the crossover of frequency ( ω c) of storage modulus ( G′) and loss modulus ( G″) in the oscillatory experiments. The activation energy ‘ E a’ of associations was investigated using the time temperature superpsition (TTS). These thermo-responsive polymers along with the biodegradability of CMG can have potential application as industrial thickening agent.

Development and Field Application of a Low-pH, Efficient Fracturing Fluid for Tight Gas Fields in the Greater Green River Basin, Wyoming

Summary Hydraulic fracturing has proved to be one of the best technologies to improve productivity from tight gas wells. In such low-permeability reservoirs, careful consideration must be given to fracturing fluid selection. Some reservoirs are underpressured and require the use of energized fluids, while others are sensitive to water-based fluids because of clay swelling and migration. Proppant pack damage because of gel residue is one of the primary causes of low production rates after hydraulic fracturing treatments. To minimize the damage and maximize production, a new premium, highly efficient fracturing fluid was developed. This premium system incorporates low-polymer-loading carboxymethyl guar polymer and a zirconium-based crosslinker. An adjustable crosslink delay makes the fluid ideal for deep-well fracturing and coiled-tubing treatment as frictional pressure losses can be minimized. The system can be energized or foamed with carbon dioxide (CO2) and nitrogen (N2) or may also be used in binary foam systems. This paper will provide details on the new fracturing fluid system, in terms of proppant pack cleanup, rheological properties, and fluid loss, as well as other parameters. Various rheological evaluations using high-pressure, high-temperature rheometers as well as a foam loop, fluid leakoff testing, proppant pack conductivity, and regain permeability evaluations are presented. Field case histories will evaluate fracturing treatments using new fracturing fluid and comparable treatments using conventional fluid. Normalized production data of the treated wells of both systems are also compared.