Carboxymethyl Locust Bean Gum Research Articles

Locust bean gum glutarate nanocomposite hydrogel microspheres of gliclazide: Optimization by box-Behnken design and preclinical evaluation of anti-diabetic efficacy

In this study, carboxymethyl locust bean gum was synthesized and nanocomposite hydrogel microspheres (GHMs) of gliclazide were produced based on nanosilicate reinforcement and aluminium-ion driven gelation process, followed by covalent crosslinking with glutaric anhydride (GA). The effect of three independent variables (polymer and GA concentration, incubation time) on the drug entrapment efficiency (DEE%) and percent drug release at 8 h, was optimized using Box-Behnken design. The highest DEE (%) and lowest drug release was achieved at the following optimized conditions: polymer (2.43 %), GA (0.34 %), and incubation (27 min). The nanoscilicate-enriched matrix provided a maximum of 75.13 % DEE, 92.33 % gel fraction, and excellent flowability. The optimized microspheres had virtually spherical morphology, according to FE-SEM analysis. FTIR study indicated a hydrogen bonding interaction between the drug and other formulation components. X-ray and DSC measurements suggested that the crystallinity of the drug decreased following integration into the matrix. The optimized GHM demonstrated anomalous diffusion of gliclazide in simulated gastrointestinal fluids for 12 h without disintegration. In streptozotocin (50 mg/kg BW)-induced diabetic rats, the optimized formulation diminished blood glucose level by about 72 % in 12 h. Thus, the nanocomposite GHMs created by combining nanosilicate with GA had an outstanding potential for long-term control of diabetes.

Smart karaya-locust bean gum hydrogel particles for the treatment of hypertension: Optimization by factorial design and pre-clinical evaluation

This investigation was undertaken to unveil the controlled drug delivery and preclinical anti-hypertensive potential of a novel interpenetrating biopolymer-based network of karaya gum and carboxymethyl locust bean gum (CLBG). The Williamson synthesis of CLBG was confirmed after analyzing FTIR spectra, degree of O-carboxymethyl group substitution and viscosity. The hydrogel particles (HPs) were developed using aluminium chloride solution as cross-linker. A full 32 factorial design approach was adopted for the optimization of two responses: drug entrapment efficiency and drug release (%) in simulated gastrointestinal conditions at 10 h. FE-SEM images and EDX spectra supported the formation of spherical HPs and successful entrapment of the drug in the HPs. Depending upon formulation variables, the drug entrapment efficiency of the HPs lied in the range of 84–98%. The HP matrix was chemically compatible for carvedilol phosphate as was suggested by infrared, thermal and x-ray analyses. The swelling kinetics of HPs corroborated well with the pH-dependent in vitro drug discharge characteristics. The drug release from HPs was found to follow anomalous transport mechanism with varying contribution of simple diffusion and polymer relaxation as was elucidated by Peppas-Sahlin model equation. Preclinical data suggested that the optimized HPs had an excellent blood pressure lowering activity in male Swiss albino mice up to 10 h.

Effect of polymer concentration and solution pH on viscosity affecting integrity of a polysaccharide coat of compression coated tablets

Tablets, compression coated with certain polysaccharides and intended for colon delivery, retain the integrity of the coat for an initial period of about 6 h (lag period) beyond which (post-lag period) the coat is degraded by colonic enzymes to induce drug release. This work was undertaken to investigate the factors which influence the integrity of the coat during the lag period. Core tablets containing two model drugs were compression coated with various amounts of carboxymethyl locust bean gum (CMLBG). In-vitro release of drugs, erosion of coat, and steady shear viscosity of CMLBG solutions having different concentrations and solution pH were determined. The viscosity of CMLBG that depended primarily on CMLBG concentration and partly on solution pH was responsible for erosion and integrity of the coat in the lag period. Evaluation of polymer viscosity could describe the integrity of coat of a polysaccharide coated tablet in the lag period.

Effect of carboxymethylation on rheological and drug release characteristics of locust bean gum matrix tablets

This study was undertaken to investigate correlation between the carboxymethylation-induced rheological changes and drug release characteristics of locust bean gum (LBG) matrix tablets. LBG was derivatized to carboxymethyl LBG (CMLBG) and characterized by 13C NMR, FTIR and elemental analyses. Rheological studies revealed that LBG, in contact with water, produced a strong elastic gel which swelled less due to lower penetration of water resulting in slower drug release. On the other hand, CMLBG formed a viscous polymer solution through which higher influx of water resulted in rapid swelling of the matrix and faster drug release. Although the release from a particular matrix was dependent on drugs’ solubilities, CMLBG matrix tablet produced faster release of all the drugs than LBG matrix tablets. In conclusion, rheological study appeared to be an useful tool to predict release of drugs from polysaccharide matrix tablets.

Impact of gelation period on modified locust bean-alginate interpenetrating beads for oral glipizide delivery

In this work, the effect of hydrogelation period in the design of glipizide-loaded biopolymer-based interpenetrating network (IPN) beads was investigated. Carboxymethyl locust bean gum and sodium alginate IPN beads were prepared by ionic crosslinking method using aqueous aluminium chloride salt solution as gelation medium. The longer exposure of the IPN beads in the gelation medium caused a considerable loss of the drug (∼8%), and also affected their surface morphology and drug release performance. Spherical shape of the IPN beads was observed under scanning electron microscope (SEM). The diameter of IPN beads increased with increasing gelation time. The IPNs cured for 0.5h exhibited slower drug release kinetics in HCl (pH 1.2) and phosphate buffer (pH 7.4) solution than those incubated for 1–2h. The drug release occurred at a faster rate in phosphate buffer solution and continued for a minimum period of 8h. The IPNs cured for the lowest period obeyed polymer chain-relaxation phenomenon as dominating mechanism for drug release. However, all the IPNs followed anomalous mechanism of drug transport. The drug release corroborated well with pH-dependent swelling behaviors of the IPNs. Thus, IPN beads cured for 0.5h were found most suitable for controlled delivery of BCS class II anti-diabetic drug glipizide.

A RP-HPLC method for quantification of diclofenac sodium released from biological macromolecules

Interpenetrating network (IPN) microbeads of sodium carboxymethyl locust bean gum (SCMLBG) and sodium carboxymethyl cellulose (SCMC) containing diclofenac sodium (DS), a nonsteroidal anti-inflammatory drug, were prepared by single water-in-water (w/w) emulsion gelation process using AlCl3 as cross-linking agent in a complete aqueous environment. Pharmacokinetic study of these IPN microbeads was then carried out by a simple and feasible high-performance liquid chromatographic method with UV detection which was developed and validated for the quantification of diclofenac sodium in rabbit plasma. The chromatographic separation was carried out in a Hypersil BDS, C18 column (250mm×4.6mm; 5m). The mobile phase was a mixture of acetonitrile and methanol (70:30, v/v) at a flow rate of 1.0ml/min. The UV detection was set at 276nm. The extraction recovery of diclofenac sodium in plasma of three quality control (QC) samples was ranged from 81.52% to 95.29%. The calibration curve was linear in the concentration range of 20–1000ng/ml with the correlation coefficient (r2) above 0.9951. The method was specific and sensitive with the limit of quantification of 20ng/ml. In stability tests, diclofenac sodium in rabbit plasma was stable during storage and assay procedure.

Al3+ ion cross-linked interpenetrating polymeric network microbeads from tailored natural polysaccharides

Interpenetrating network (IPN) microbeads of sodium carboxymethyl locust bean gum (SCMLBG) and sodium carboxymethyl cellulose (SCMC) containing diclofenac sodium (DS), a non steroidal anti-inflammatory drug were prepared by single water-in-water (w/w) emulsion gelation process using AlCl3 as cross-linking agent in a complete aqueous environment. The influence of different variables like total polymer concentration, gelation time and crosslinker content on in vitro physico-chemical characteristics and drug release rate in different media was investigated. Drug loaded microbeads were evaluated through Fourier transform infra-red (FTIR), X-ray diffraction (XRD) and differential scanning calorimetry (DSC) analyses. Scanning electron microscopy (SEM) micrograph of the beads suggested the formation of spherical particles. FTIR analysis indicated the stable nature of the drug in the blend microbeads. DSC and XRD analysis revealed amorphous state of drug after encapsulation. The drug release profile in acidic medium was considerably less in comparison to alkaline media. Formulations showed non-Fickian type transport mechanism. These tri-valent ion crosslinked beads not only improve drug encapsulation efficiency but also enhance drug release in phosphate buffer.

Gastrointestinal delivery of glipizide from carboxymethyl locust bean gum–Al3+–alginate hydrogel network: In vitro and in vivo performance

AbstractSodium alginate and carboxymethyl locust bean gum (CMLBG) were reticulated in an aqueous solution of AlCl3, and this novel interpenetrating network (IPN) hydrogel encapsulated about 93–98% glipizide. The degree of reticulation in the spherical IPN beads was confirmed by Fourier transform infrared spectroscopy, elemental analysis, neutralization equivalent determination, tensile strength testing, and differential scanning calorimetry analysis. An increase in the CMLBG weight ratio and the degree of crosslinking in the IPN was found to increase mean dissolution time of the encapsulated drug. The dissolution efficiency was found to be much higher in the medium at pH 7.4 than at pH 1.2. The swelling of IPN depended on the pH of the medium, and accordingly, monitored the drug release for a period of 8 h. The anomalous drug transport mechanism was presumed to be operative. High performance liquid chromatography (HPLC) analysis showed the drug's stability in the IPN during encapsulation. The IPN showed significant hypoglycemic activity on male Wistar rats for up to 10 h. This could be beneficial for diabetic patients for achieving control over blood glucose levels. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013