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Uptake of Bile Acid into Calcium-Induced Alginate Gel Beads Containing β-Chitosan Weak Acid Salt  [PDF]
Yoshifumi Murata, Kyoko Kofuji, Norihisa Nishida, Ryosei Kamaguchi
Pharmacology & Pharmacy (PP) , 2014, DOI: 10.4236/pp.2014.54042

Recently, potential applications for β-chitosan (β-CS) have been examined. In the present study, calcium-induced alginate gel beads (Alg-Ca) containing weak acid salts of β-CS were prepared and examined with regard to their ability to adsorb bile acids in vitro. More than 70% of taurocholate dissolved in solution was taken up by Alg-Ca containing 100 mg β-CS, sim. ilar to the degree of uptake observed with Alg-Ca containing α-CS salt. The adsorption of bile acid was affected by the absolute amount of β-CS and/or the acid concentration of the preparation. A secondary bile acid, taurodeoxycholate, was also adsorbed by Alg-Ca containing weak acid salts of β-CS. Therefore, β-CS might be used to adsorb bile acids within the gastrointestinal tract in the same manner as an anion-exchange resin, and thus serve as a complementary means by which to prevent hyperlipidemia.

Properties of an Oral Preparation Containing a Chitosan Salt  [PDF]
Yoshifumi Murata,Youko Kodama,Daijirou Hirai,Kyouko Kofuji,Susumu Kawashima
Molecules , 2009, DOI: 10.3390/molecules14020755
Abstract: The 2-(4-chlorophenoxy)-2-methylpropionic acid (CMP) salt of chitosan (CS), CS-CMP, and that of a CS derivative (CP), were prepared and their ability to adsorb bile acids investigated. CS-CMP and CP-CMP rapidly adsorbed taurocholate (TCA) and glycocholate (GCA) when these bile acids were present together in the medium, with simultaneous release of CMP. A secondary bile acid, taurodeoxycholate, was preferentially adsorbed over TCA and GCA. Alginate gel beads containing CS-CMP did not differ from CS-CMP alone in their manner of bile acids take up. Furthermore, oral administration of CS-CMP to rats resulted in decreased serum cholesterol and triacylglycerol levels for two weeks. Therefore, CS-CMP, as well as a vehiclecontaining CS-CMP, might be a useful agent with which to treat hyperlipidemia
Chitosan and chemically modified chitosan beads for acid dyes sorption


环境科学学报(英文版) , 2009,
Abstract: The capabilities of chitosan and chitosan-EGDE (ethylene glycol diglycidyl ether) beads for removing Acid Red 37 (AR 37) and Acid Blue 25 (AB 25) from aqueous solution were examined. Chitosan beads were cross-linked with EGDE to enhance its chemical resistance and mechanical strength. Experiments were performed as a function of pH, agitation period and concentration of AR 37 and AB 25. It was shown that the adsorption capacities of chitosan were comparatively higher than chitosan-EGDE for both acid dyes. This is mainly because cross-linking using EGDE reduces the major adsorption sites -NH3+ on chitosan. Langmuir isotherm model showed best conformity compared to Freundlich and BET. The kinetic experimental data agreed very well to the pseudo second-order kinetic model. The desorption study revealed that after three cycles of adsorption and desorption by NaOH and HCl, both adsorbents retained their promising adsorption abilities. FT-IR analysis proved that the adsorption of acid dyes onto chitosan-based adsorbents was a physical adsorption. Results also showed that chitosan and chitosan-EGDE beads were favourable adsorbers and could be employed as low-cost alternatives for the removal of acid dyes in wastewater treatment.
Influence of coating on the triamcinolone release of alginate chitosan beads for colonic drug delivery  [PDF]
Nadir Veiga Vier, Ruth Meri Lucinda-Silva
Natural Science (NS) , 2011, DOI: 10.4236/ns.2011.311122
Abstract: The aim of this study was to evaluate the effect of coating of alginate-chitosan (AL:CS) beads on the colonic drug delivery. The AL:CS systems containing triamcinolone (TC) were coated with the HPMCP and Eudragit? L100 by immersion and by spraying methods. The drug release profile in simulated colonic medium was determined using 5% human fecal content suspension in 0.01 N buffer solution, pH 6.8. The systems coated with HPMCP showed a lower rate of drug delivery in simulated enteric medium. The delivery profile in simulated colonic medium followed zero-order kinetic. The coated systems provided a promising drug-delivery profile for application in colonic drug delivery.
Alginate Reinforced Chitosan and Starch Beads in Slow Release Formulation of Imazaquin Herbicide—Preparation and Characterization  [PDF]
Lami A. Nnamonu, Rufus Sha’Ato, Ikenna Onyido
Materials Sciences and Applications (MSA) , 2012, DOI: 10.4236/msa.2012.38081
Abstract: In a bid to make slow release formulations of imazaquin, the herbicide was encapsulated in starch and chitosan beads reinforced with alginate. The beads were characterized using SEM, DSC and FTIR. Two types of formulations were made by extrusion into 0.25 M calcium chloride solution: chitosan/alginate (LNCI) and starch/alginate (LNSI) beads, and the third was by gelatinization of starch at 75?C (LNSI2). Findings showed highly porous spherical beads, the starch/alginate beads bigger and less porous than the chitosan/alginate beads with diameters of 2.53 ± 0.01 and 2.31 ± 0.01 mm; porosity of 57.58% ± 0.2% and 81.28% ± 0.2% and swelling of 34.91% ± 0.2% and 80.35% ± 0.2%, respectively. FTIR revealed a reduction in intensity of the carboxylate peaks of alginate and the peak at 1058 cm?1, present in the FTIR of the matrices, is shifted to lower wave-numbers in the formulations, signifying interactions between the formulation components that make for good slow release. The DSC thermograms of all formulations showed evidence of interaction of imazaquin carboxylate group with the N-atoms of the macromolecules, which is indicative of reduced crystallinity of imazaquin.
Evelina Ivanova, Valentina Chipeva, Iskra Ivanova, Xavier Dousset and Denis Poncelet
Journal of Culture Collections , 2002,
Abstract: Investigations on encapsulation of lactic acid bacteria in alginate beads were carried out. For this purpose a bacteriocin producing strain Enterococcus faecium A 2000 was used. For the production of capsules with a small diameter (0.8-1 mm) an electrostatic generator was applied. To enhance of the capsule stability, the fermentation was performed in modified MRS medium without phospates and with addition of CaCl2 . As a result of the immobilization the bacteriocin production was increased with approximately 50 %, compared with the batch fermentation with free cells. The immobilized cells could be reuses up to three times after filtration and re-suspension in new medium.
Characterization and Biodegradation Studies for Interpenetrating Polymeric Network (IPN) of Chitosan-Amino Acid Beads  [PDF]
Manjusha Rani, Anuja Agarwal, Yuvraj Singh Negi
Journal of Biomaterials and Nanobiotechnology (JBNB) , 2011, DOI: 10.4236/jbnb.2011.21010
Abstract: The paper describes the synthesis of pH sensitive interpenetrating polymeric network (IPN) beads composed of chi-tosan, glycine, glutamic acid, cross linked with glutaraldehyde and their use for controlled drug release. The drug was loaded into beads by varying their composition such as, amount of crosslinker glutaraldehyde, ratio of chitosan, glycine and glutamic acid. The beads were characterized by fourier transform infrared (FTIR) spectroscopy to confirm the cross linking reaction and drug interaction with crosslinked polymer in beads, Scanning Electron Microscopy (SEM) to understand the surface morphology and Differential scanning calorimetry (DSC) to find out the thermal stability of beads. X-Ray Diffraction (XRD) investigation was carried out to determine the crystalline nature of drug after loading into chitosan-glycine-glutamic acid IPN beads. Results indicated amorphous dispersion of chlorpheniramine maleate (CPM) in the polymeric matrix. The swelling behavior of the beads at different time intervals was monitored in solutions of pH 2.0 and pH 7.4. The release experiments were performed in solutions of pH 2.0 and pH 7.4 at 37oC using chlorpheniramine maleate (CPM) as a model drug. The swelling behavior and release of drug were observed to be dependent on pH, degree of cross linking and their composition. The results indicate that the cross linked IPN beads of chitosan-glycine-glutamic acid might be useful as a vehicle for controlled release of drug. The kinetics of drug release from beads was best fitted by Higuchi’s model in which release rate is largely governed by rate of diffusion through the matrix.
Enhanced Hemostatic Performance of Tranexamic Acid-Loaded Chitosan/Alginate Composite Microparticles
Donghong Li,Pengxi Li,Jiatao Zang,Jiancang Liu
Journal of Biomedicine and Biotechnology , 2012, DOI: 10.1155/2012/981321
Abstract: Novel microparticles based on chitosan and sodium alginate were prepared using emulsification and cross-linking technologies. The spherical microparticles had a porous surface and a diameter of  m. In simulated body fluid, these microparticles quickly swelled but gradually degraded. The results of the MTT assay revealed that a slight inhibition of cell proliferation was observed on day 2 and then gradually decreased afterward. No cell morphology changes were observed. By loading tranexamic acid, the hemostatic performance of the microparticles was obviously improved. Using fast-acting styptic powder (Flashclot) as the control, the hemostatic efficiency was investigated in rabbits using a liver transection bleeding model. It was found that both Flashclot and the microparticles achieved hemostasis in  min and  min, respectively; however, the tranexamic acid-loaded microparticles stopped the bleeding in  min (). Additionally, Flashclot resulted in heat injury to the experimental livers, while the microparticles did not. Thus, with their biodegradability, safety, and superior hemostatic efficiency, tranexamic acid-loaded microparticles might be a promising new powdered hemostatic agent with a wide range of potential applications.
Alginate-Chitosan Particulate System for Sustained Release of Nimodipine
A Rajendran, SK Basu
Tropical Journal of Pharmaceutical Research , 2009,
Abstract: Purpose: The aim of this work was to prepare nimodipine-loaded alginate-chitosan beads for sustained drug release. Methods: Nimodipine-loaded alginate-chitosan beads were prepared by ionic gelation method using various combinations of chitosan and Ca2+ as cations and alginate as anion. The swelling ability and in vitro drug release characteristics of the beads were studied at pH 1.2 and 6.8. Infra-red (IR) spectrometry, scanning electron microscopy (SEM), differential scanning calorimetry (DSC), x-ray diffraction (XRD), and atomic absorption spectroscopy (AAS) were also applied to investigate the physicochemical characteristics of the drug in bead formulations. Results: The surface morphology, size, and drug loading of the beads varied with increase in the concentration of chitosan and calcium chloride in the gelation medium. The swelling ability of the beads in different pH media was dependent on the presence of a polyelectrolyte complex in the beads and the pH of the media. Both calcium alginate beads and the beads treated with chitosan failed to release the drug at pH 1.2 over the period of study. On the other hand, at pH 6.8, calcium alginate beads released approx. 96 % of drug in 6 h, but treatment of the beads with chitosan lowered drug release to 73 %. Drug release mechanism was either “anomalous transport” or “case-II transport”. Data from characterisation studies indicate that there was no significant change in the physical state of the drug in the bead formulations
Effect of Acidic Medium on Swelling and Release Behaviors of Chitosan-Reinforced Calcium Pectinate Gel Beads  [cached]
Pornsak Sriamornsak,Kanokporn Burapapadh,Satit Puttipipatkhachorn,Jurairat Nunthanid
Silpakorn University Science and Technology Journal , 2008,
Abstract: Chitosan-reinforced calcium pectinate (ChCP) gel beads were prepared by ionotropic gelation method. The swelling of ChCP gel beads and release behavior of indomethacin from the beads were investigated and compared with conventional calcium pectinate (CP) gel beads. The factors, such as molecular weight of chitosan, concentration of chitosan, and release medium, which can have a significant effect on the swelling and release behaviors from the beads, were discussed in this study. The mechanical test showed that the ChCP beads have slightly higher strength than that of CP beads. The swelling index of the ChCP beads in acidic medium was much lower than that in neutral medium. The release of indomethacin from ChCP beads under conditions mimicking intestinal transit were evaluated in pH 7.4 Tris buffer. The acid pretreatment caused a faster drug release from ChCP beads. The less swelling in acidic medium and faster drug release of acid-pretreated ChCP beads may be due to the dissolution of chitosan from the beads in acidic medium, as no fluorescence signal was seen at the shell of the beads. The results suggested that the acid, which essentially found in stomach, influenced the swelling and release behaviors of ChCP beads.
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