Sodium Alginate Polymer Research Articles

Smart porous microparticles based on gelatin/sodium alginate polyelectrolyte complex

Porous microparticles of different sizes were prepared by polyelectrolyte complexation of biopolymers gelatine A and sodium alginate for microencapsulation of food bioactives. The optimum pH and ratio between the polymers sodium alginate and gelatine for maximum complexation was found as 3.7 and 1:3.5 respectively. Effect of various factors like amount of surfactant, concentration of polymer and crosslinker on the formation, size and porous/nonporous nature of the microparticles were investigated. The particles’ diameter on swelling at pH=7.4 was twice that at pH=1.2 indicating the pH responsiveness. These microparticles were used as carrier for ascorbic acid. The surface morphology and sizes of the microparticles were investigated by scanning electron microscope (SEM). Fourier transform infrared spectroscopy (FTIR) study indicated the formation of polyelectrolyte complex between gelatine and sodium alginate and successful encapsulation of ascorbic acid into the microparticles. The microparticles were further characterized by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and X-ray diffraction (XRD) study.

Formulation and Optimization of Natural Polysaccharide Hydrogel Microbeads of Aceclofenac Sodium for Oral Controlled Drug Delivery

The objective of this study was to prepare and evaluate calcium alginate (CA) microbeads with calcium chloride as cross-linking agent for aceclofenac sodium by ionotropic external gelation method. Calcium alginate microbeads represent a useful tool for oral sustained/ controlled drug delivery but show several problems, mainly related to the stability, and rapid drug release at higher pH that, in most cases, is too fast due to increase porosity. To overcome such inconveniences, which was to develop CA microbeads coated with Guar gum (GG) and Locust bean gum (LBG) as drug release modifiers to improve stability and prolong the drug release. While increasing in the concentration of sodium alginate and other polymer dispersion increased size distribution, flow properties, mean particle size, swelling ratio and drug entrapment efficiency. The mean particle sizes of drug-loaded microbeads were found to be in the range 596.45±1.04 to 880.10±0.13. The drug entrapment efficiency was obtained in the range of 63.24±0.66 to 99.75±0.87. The shape and surface characteristics were determined by scanning electron microscopy (SEM). No significant drug-polymer interactions, physical changes and crystallinity of the drug in the formulations were determined by FT-IR spectroscopy, differential scanning calorimetry (DSC) and X-ray diffraction [XRD]. In-vitro drug release profiles of microbeads were pH dependent and were analyzed by different kinetic models. The mechanism of drug release from microbeads depends on swelling and erosion process resulting CA microbeads was diffusion controlled followed by First order kinetics and whereas CA microbeads coated with GG and LBG approaching to near Zero- order kinetics.

FORMULATION AND EVALUATION OF INSITU MUCOADHESIVE NASAL GELS OF METOCLOPRAMIDE HYDROCHLORIDE

The prolonged residence of drug formulation in the nasal cavity is of utmost importance for intranasal drug delivery. The objective of the present investigation was to develop a mucoadhesive in situ gel with reduced nasal mucocilliary clearance in order to improve the bioavailability of the antiemetic drug, Metoclopramide Hydrochloride. The in situ gelation upon contact with nasal mucosa was conferred via the use of the thermogelling Methyl cellulose whereas mucoadhesion and drug release enhancement were modulated via the use of sodium alginate and polyethylene glycol polymers respectively. The results revealed that the mucoadhesive polymer increased the gel viscosity but reduced its sol gel transition temperatures and the drug release. The inclusion of polyethylene glycol polymer counteracted the effect of mucoadhesive polymer where by it decreased the gel consistency and increased the sol gel transition as well as in vitro drug diffusion. The in vitro tests performed for mucoadhesive strength and drug diffusion showed that nasal in situ gelling formulations prepared are having good mucoadhesive strength with nearly100% drug diffusion within four hours. So this study points to the potential of mucoadhesive in situ nasal gel in terms of ease of administration, accuracy of dosing, prolonged nasal residence and improved nasal bioavailability.

Characterization of Immobilized L-Asparaginase Produced from Pseudomonas aeruginosa 50071 by Solid State Fermentation

The natural polymer sodium alginate is a macropolysaccharide Produced from brown algae has many applications. Anti-leukemia enzyme L-asparaginase (LASNase) produced from Pseudomonas aeruginosa 50071 by solid state fermentation was covalently conjugated on sodium alginate. SDS-PAGE showed that the purified LASNase was homogeneous with molecular weight of ~ 113 KDa. The immobilized enzyme on 3% sodium alginate showed specific activity of 62 U/mg protein. The immobilized L-ASNase maintained over 90 % of the original activity of free enzyme. Also it showed a slightly thermal stability where the activation energy of denaturation were 28 and 35 Kcal mol-1 for both native and immobilized enzyme, respectively. The Km of sodium alginate immobilized enzyme was about 2 times lower than that of the free enzyme.

FORMULATION AND EVALUATION OF MICROSPHERES CONTAINING IMATINIB MESYLATE USING SODIUM ALGINATE BY CHEMICAL CROSS LINKING METHOD

The present research deals with formulation of microspheres containing an Anti-cancer drug Imatinib mesylate reduce the side effects and frequency of dosing. It is currently registered and used for two indications, Chronic Myeloid Leukemia (CML) and Gastrointestinal Stromal Tumors (GISTs). Imatinib mesylate loaded microspheres was formulated by using Sodium Alginate polymer by Chemical CrossLinking method to develop a sustained release dosage form. The effect of concentration of polymer ratio on the microspheres properties like percentage of drug loading, biodegradability, drug release kinetics, particle size, encapsulation efficiency, angle of repose, bulk density, SEM, DSC and XRD were investigated in our study. Moreover, the kinetics of Imatinib Meyslate released from different formulations of microspheres were analyzed using four different theoretical models, that is Zero order, First order, Peppa’s and Higuchi models. Microspheres prepared with Glutaraldehyde showed different release kinetics. Increasing the polymer concentration decreased the release rate of Imatinib Meyslate from microspheres because of formation of greater structural strength and more tightly texture with the drug. Besides, microspheres gave an adequate fit to either zero order or first order kinetic models, depending on the extent of cross linking reaction between drug and the cross linking agent. Key Words: Sodium Alginate, Imatinib Mesylate, microsphere, chemical cross linking, release kinetics.

Controlled antiseptic release by alginate polymer films and beads

Biodegradable polymeric materials based on blending aqueous dispersions of natural polymer sodium alginate (NaAlg) and povidone iodine (PVPI) complex, which allow controlled antiseptic release, are presented. The developed materials are either free standing NaAlg films or Ca2+-cross-linked alginate beads, which properly combined with PVPI demonstrate antibacterial and antifungal activity, suitable for therapeutic applications, such as wound dressing. Glycerol was used as the plasticizing agent. Film morphology was studied by optical and atomic force microscopy. It was found that PVPI complex forms well dispersed circular micro-domains within the NaAlg matrix. The beads were fabricated by drop-wise immersion of NaAlg/PVPI/glycerol solutions into aqueous calcium chloride solutions to form calcium alginate beads encapsulating PVPI solution (CaAlg/PVPI). Controlled release of PVPI was possible when the composite films and beads were brought into direct contact with water or with moist media. Bactericidal and fungicidal properties of the materials were tested against Escherichia coli bacteria and Candida albicans fungi. The results indicated very efficient antibacterial and antifungal activity within 48h. Controlled release of PVPI into open wounds is highly desired in clinical applications to avoid toxic doses of iodine absorption by the wound. A wide variety of applications are envisioned such as external and internal wound dressings with controlled antiseptic release, hygienic and protective packaging films for medical devices, and polymer beads as water disinfectants.

Preparation and characterization of hydrogels based on homopolymeric fractions of sodium alginate and PNIPAAm

Graft copolymers were prepared by formation of an amide bond between poly-α-l-guluronic acid (MW 24,000), isolated from sodium alginate and the free amino group of PNIPAAm-NH2. SEM micrographs revealed the formation of a macroscopic network on the surface of the grafted hydrogels with a porosity diameter of 10–20μm. Semi-IPN hydrogels were prepared using different proportions of sodium poly-β-d-mannuronate (MW 21,000), isolated from sodium alginate and cross-linked PNIPAAm-NH2 polymers. SEM micrographs showed porosities of minor size (∼5μm). Though both types of hydrogels are good water containers, the water retention capacity of graft copolymers is more than 50% higher than that of semi-IPN hydrogels. Both hydrogel types showed significant changes in swelling ratios between 20 and 45°C: the swelling ratio decreases near the LCST of PNIPAAm. The water absorption and retention capacity of graft hydrogels increases with pH, reaching a maximum value at pH 7.0.

Diffusion coefficients in viscous sodium alginate solutions

Sodium alginate solution, being viscous hydrocolloid, was examined voltammetrically in the context of viscous effects by use of a ferrocenyl compound as a redox probe. Voltammograms were almost independent of concentrations of sodium alginate even in a solid-like state. Diffusion coefficients of the ferrocenyl compound did not vary with viscosity evaluated by a viscometer. Ionic conductivity of sodium alginate was also independent of the viscosity. In contrast, diffusion coefficients of the latex particle 0.84μm in diameter decreased with an increase in the viscosity. The intrinsic viscosity was evaluated. The value is equivalent to the volume as large as 3m3 of water in which one mole of the unit of sodium alginate polymer generates the viscosity. Consequently, redox species diffuse through water portions circumventing the alginate network. As an application, sodium alginate solutions were used for long-time chronoamperometry. The current was decayed with the time even of 1500s without any effect of natural convection, whereas that in the aqueous solution was irreproducible for times longer than 20s. The other application was electroplating of silver. The silver surface deposited in sodium alginate had no morphology by the SEM image, while the surface plated without sodium alginate showed morphology even on an optical microscopy scale.

Coagulation performance and floc characteristics of aluminum sulfate using sodium alginate as coagulant aid for synthetic dying wastewater treatment

The effect of coagulant aid sodium alginate (SA) on coagulation behavior and floc characteristics of aluminum sulfate (AS) was investigated for synthetic dye wastewater treatment. Coagulation performance and floc characteristics of AS were investigated for comparison. The results showed that AS plus SA exhibited synergic effect on color removal depending on the dose of AS and SA. Color removal was more enhanced by SA at low AS doses than at higher ones. Floc properties including floc growth rate, size, strength and reversibility were investigated by Photometric Dispersion Analyzer (PDA). AS plus polymer SA exhibited an obvious improvement on floc size and floc growth rate. Besides, the AS–SA dual-coagulants significantly improved the floc recoverability as reflected by higher recovery factors compared to AS.

Development and characterization of polylactic acid bandage coated with biopolymers and drugs for wound healing

For the present work, polylactic acid yarn (140 denier) was used for the production of bandage. The physical properties of fabric were measured. Chitosan–sodium alginate, calcium alginate–sodium alginate polymer and their blends were coated separately on the bandage to incorporate wound healing, haemostatic, easy removal, biocompatibility and antibacterial property. The polymer-coated samples were subjected to scanning electron microscope (SEM) and Fourier transform infrared spectroscopy (FT-IR) analysis. Bacteria present in wound samples were found using different bio-chemical methods. Antibiotic drugs were selected based on the antibiotic sensitivity test. The polymer-coated bandages have been further immobilized with tetracycline, chloramphenicol and rifampin drug to increase the rate of wound healing and antibacterial activity. The drug-loaded samples were subjected to drug release study for about four days in a static condition. All coatings showed a continuous drug release for about four days. Further, the antibacterial activity of the drug-loaded and polymer-coated samples was evaluated against http://en.wikipedia.org/wiki/Staphylococcus_aureus and Proteus bacteria. It is concluded that chitosan, sodium alginate and calcium alginate coated with tetracycline and chloramphenicol drug-immobilized bandages are highly effective against bacteria.

An Investigation of the Dimensional Changes of Polymer Mixture Tablets Containing a Soluble Drug, Using an Image Analysis Method. Influence of These Characteristics on Drug Release and Its Mechanism

The properties and characteristics of the polymer used for the preparation of matrix drug delivery systems considerably influence their performance and the extent of drug release and its mechanism. The objective of this research was to examine the dimensional changes, and gel evolution of polymer matrices consisting of three different polymers Polyox, sodium alginate (hydrophilic) and Ethocel (hydrophobic), using an image analysis method. Furthermore to explore how these changes influence the release rate of a soluble drug namely, venlafaxine. All tablets displayed marked dimensional expansion and gel growth particularly those consisting of two hydrophilic polymers Polyox/sodium alginate (POL/SA/V) compared to those consisting of the hydrophilic/hydrophobic Polyox/Ethocel (POL/ET/V). Similarly the thickness of the gel layer in POL/SA/V matrices increased considerably with time up to 8 hours. In general our findings show that the POL/SA/V matrices, due to their thicker gel layer produced a more effective barrier which results in a more pronounced sustained release delivery. This accounts for the slower and smaller overall drug release observed with the POL/SA/V matrices compared to those containing POL/ET/V and indicates that the formation of a thick and durable gel barrier is a characteristic necessary for the preparation of sustained drug release systems. Moreover the solubility of venlafaxine in combination with the polymer’s properties appears to play an important role on the extent of drug release and the release mechanism. Overall the polymer mixtures examined comprise a useful and promising combination of materials for the development and manufacture of sustained release preparations based on these polymers.

Effect of Permeation Enhancers on Buccal Absorption

This paper reports an investigation on matrices based on the mucoadhesive polymers hydroxypropylmethylcellulose and sodium alginate, intended for sublingual administration of 1 mg lorazepam (LZ, 7-chloro-5-(2-chlorophenyl)-1,3-dihydro-3-hydroxy-2H-1,4-benzodiazepin-2-one, CAS 846-49-1). The effect of different amounts of three permeation enhancers, cetylpyridinium chloride (CPC), polyethoxylated castor oil (PCO) and polyethylene glycol dodecyl ether (PGDE) on LZ permeation from the matrices was investigated using three models: (a) cultured monolayer of human buccal epithelial cells; (b) hamster cheek pouch mucosa in vitro, and (c) buccal administration to rabbits in vivo. In the first two models the presence of promoters, except when present at the higher concentrations, increased the drug permeation rate. The permeation-reducing effect was rationalized on the basis of micellar complexation of the drug. In the living rabbit (c) model, only CPC at the highest tested concentration was moderately active, while in the cultured cell model activity differences among the enhancers were less evident. Different effects of the promoters in the ex vivo and in vivo models were tentatively explained on the basis of the structural characteristics of the absorbing membranes. The present study, while confirming the efficacy of CPC as promoter in models involving biological membranes, does not provide conclusive data on the validity of the cultured cells model for assessment of buccal drug absorption.

Production of bioethanol by immobilized Saccharomyces Cerevisiae onto modified sodium alginate gel

AbstractBACKGROUND: Microbial bioethanol production is an important option in view of the finite global oil reserves. Bioethanol fermentation was carried out using immobilized microorganisms (Saccharomyces cerevisiae, Zymomonas mobilis, Pichia stipitis, etc.), which has many advantages compared with the use of free cells. Various support materials have been used for bioethanol fermentation, and alginate gels have been one of the most widely used matrices for cell entrapment. The aim of this study was increased bioethanol production by Saccharomyces cerevisiae immobilized on alginate gels. First, N‐vinyl‐2‐pyrrolidone was grafted onto sodium alginate. Then, the properties of ethanol production were investigated using the matrix obtained.RESULTS: The performance of ethanol fermentation was affected by calcium chloride concentration, N‐vinyl‐2‐pyrrolidone grafted onto the sodium alginate, sugar concentration and the percentage of immobilized cell beads. These effects were optimized to give maximum ethanol production. Ethanol production was accelerated when sodium alginate polymer was modified with N‐vinyl‐2‐pyrrolidone. The maximum concentration, productivity and yield of ethanol were 69.68 g L−1, 8.71 g L−1 h−1 and 0.697 g g−1, respectively.CONCLUSION: The new polymeric matrix, when compared with sodium alginate, showed better ethanol production due to the hydrophilic property of N‐vinyl‐2‐pyrrolidone. The results suggest that the proposed method for immobilization of Saccharomyces cerevisiae has potential in industrial applications of the ethanol production process. Copyright © 2011 Society of Chemical Industry

Magnetic nanoparticles coated with polysaccharide polymers for potential biomedical applications

This study reports a two-steps route for obtaining magnetic nanoparticles–polysaccharide hybrid materials consisting of Fe3O4, NiFe2O4 and CuFe2O4 nanoparticles synthesis by coprecipitation method in the presence of a soft template followed by coating of ferrite nanoparticles of 8–10-nm size range with polysaccharide type polymers—sodium alginate or chitosan. Magnetic oxide nanoparticles and the corresponding hybrid materials were characterized by X-ray diffraction (XRD), Mossbauer spectroscopy, atomic absorption spectroscopy (AAS), FTIR spectroscopy, scanning and transmission electron microscopy (SEM and TEM) and specific surface area measurements. The vibrating sample magnetometry confirms the superparamagnetic properties of the synthesized ferrites and hybrids. Using this route, the percent of magnetic nanoparticles retained in chitosan-based hybrid materials is nearly double in comparison with that of sodium alginate–based materials. The biological activity tests on Escherichia coli ATCC 25922, Pseudomonas aeroginosa ATCC 27853, Staphylococcus aureus ATCC 25923 and Candida scotti microorganisms show the non-toxic properties of prepared hybrid materials.

In Situ Cross-Linking of Polyanionic Polymers to Sustain the Drug Release from Theophylline Tablets

The aim of this study was to develop an extended-release tablet formulation using a new in situ cross-linking method. The effects of polyvalent cations on theophylline release from tablets made with the polyanionic polymers sodium alginate and sodium carboxymethylcellulose, were investigated. Different miliequivalents of the di and tri-valent cation, Ca 2+ and Al 3+ , were added to tablet formulations. The results of the dissolution study showed that incorporation of cations sustained the drug release. This is due to an in situ cross-linking between the polyanionic polymers and the added cation in tablet formulation. The drug release prolongation and the release kinetics were dependent on the nature of the polymers and the cations’ concentrations and valences. The drug release rate decreased by an increase in cation concentration. The combination of the two investigated polymers decreased the drug release rate to a higher extent in comparison with formulations containing each polymer alone. A zero-order drug release kinetic was observed in formulations containing 1:1:1 ratio of drug: Na alginate: NaCMC, and the investigated cations. These results showed that the in situ cross-linking by polyanionic polymers can be used for controlling the drug release rate.

Preparation and characterization of mucoadhesive microcapsules of salbutamol sulfate

Salbutamol sulfate microcapsules with a coat consisting of sodium alginate and mucoadhesive polymer such as sodium carboxy methyl cellulose (NaCMC), methyl cellulose (MC), carbopol-934, and hydroxy propyl methyl cellulose (HPMC) were prepared by ionotropic gelation technique and were evaluated for morphological characters, drug content, loading efficiency, drug–polymer interactions, swelling ratio, mucoadhesive properties, and in vitro release. The resulting microcapsules were discrete, spherical, and free-flowing, and microencapsulation efficiency was 51.28–96.70%.The microcapsules prepared with alginate alone (A4) have exhibited good mucoadhesive property in the in vitro washoff test.The swelling ratio of microcapsules was enhanced with increased alginate concentration. Salbutamol sulfate release from these mucoadhesive microcapsules was slow and extended over a period of 8 h and depends upon the concentration of the alginate. The drug release from alginate- HPMC/carbopol microcapsules followed diffusion-controlled first-order kinetics. The release rate of alginate-HPMC microcapsules (A4H) was higher than other formulations and comparable with commercially available controlled-release capsules. Microcapsules with alginate alone (A4) followed diffusion mechanism. In conclusion, alginate-HPMC/carbopol mucoadhesive microcapsules could be promising vehicle for oral controlled release of salbutamol sulfate.

Preparation and evaluation of carboplatin biodegradable polymeric nanoparticles

The present study was designed to evaluate targeting efficiency of carboplatin anticancer drug. Drug was encapsulated in natural biodegradable polymer sodium alginate. The nanoparticles were prepared by the ion gelification technique and evaluated for encapsulation efficiency, loading capacity, in vitro release pattern and targeting efficiency. Drug encapsulation efficiency was about 52.24–68.70% for different formulations. In vitro release profile showed duration of drug release was also increased (more than 12 h) by nanoparticulate formulation as compared to pure drug (up to 3 h). The formulations were parenterally administered to laca mice and the drug was detected in body organs like liver, lungs and spleen. In case of free drug, less amount of drug was found in liver, lungs and spleen as compared to drug encapsulated nanoparticles. Thus sodium alginate nanoparticles can be used for targeting carboplatin and it can be a promising tool in the delivery of anticancer drugs.

Immobilization of pancreatic porcine lipase in calcium and barium alginate comparative studies of their kinetic properties and screening the polymer for suitability

Purpose: The objective of the study was to select a suitable polymer for immobilization of pancreatic porcine lipase by entrapment method and to evaluate the kinetic properties of immobilized enzyme with free enzyme. Method:. Enzyme was immobilized by entrapment method using calcium alginate and barium alginate polymers. Lipase activity was determined by titrimetric assay procedure. Km and Vmax were determined with Michaelis Menton Equation. Result: The present work demonstrated that calcium alginate beads loaded with enzyme is more stable at high temperature and has excellent Vmax and Km in comparison with barium alginate beads.. Compare to immobilized enzyme free enzyme could not withstand high temperature. Conclusion: Sodium alginate polymer is an excellent carrier for entrapment of pancreatic porcine lipase.

Optical constants of a sodium alginate polymer in the UV–vis range

The dispersive refractive index and the thickness of alginate polymer films have been obtained by using the envelope-extremes location technique. The uncertainty in the determination of the refractive index is of the order of 0.01. The alginate polymer has been prepared with a solution of sodium alginate with a concentration of 0.7% in weight, mixed with a 0.03 M solution of CaCl 2. Since the main application of this kind of polymers is the immobilization of living organism for biosensors, especially those based on fluorescence measurements, we focus the analysis in the ultra-violet–visible (UV–vis) spectral range.

Design and Development of Gliclazide Mucoadhesive Microcapsules: In Vitro and In Vivo Evaluation

In this study an attempt was made to prepare mucoadhesive microcapsules of gliclazide using various mucoadhesive polymers designed for oral controlled release. Gliclazide microcapsules were prepared using sodium alginate and mucoadhesive polymer such as sodium carboxymethyl cellulose (sodium CMC), carbopol 934P or hydroxy propylmethyl cellulose (HPMC) by orifice-ionic gelation method. The microcapsules were evaluated for surface morphology and particle shape by scanning electron microscope. Microcapsules were also evaluated for their microencapsulation efficiency, in vitro wash-off mucoadhesion test, in vitro drug release and in vivo study. The microcapsules were discrete, spherical and free flowing. The microencapsulation efficiency was in the range of 65-80% and microcapsules exhibited good mucoadhesive property in the in vitro wash off test. The percentage of microcapsules adhering to tissue at pH 7.4 after 6 h varied from 12-32%, whereas the percentage of microcapsules adhering to tissue at pH 1.2 after 6 h varied from 35-68%. The drug release was also found to be slow and extended for more than 16 h. In vivo testing of the mucoadhesive microcapsules in diabetic albino rats demonstrated significant antidiabetic effect of gliclazide. The hypoglycemic effect obtained by mucoadhesive microcapsules was for more than 16 h whereas gliclazide produced an antidiabetic effect for only 10 h suggesting that mucoadhesive microcapsules are a valuable system for the long term delivery of gliclazide.