Gum Microbeads Research Articles

Sustained release of acyclovir from alginate-gellan gum and alginate-xanthan gum microbeads

In the current research, acyclovir-loaded microbeads were formulated via ionotropic gelation using sodium alginate-gellan gum and sodium alginate-xanthan gum. In the preparation of these acyclovir-loaded microbeads, aluminium chloride and barium chloride were used as cross-linking agents. All these ionotropically-gelled acyclovir-loaded alginate-gellan gum microbeads and alginate-xanthan gum microbeads exhibited good percent yields (85.07 ± 1.58 to 92.17 ± 3.02%) and drug entrapment efficiencies (74.09 ± 1.38 to 95.16 ± 3.37%). Acyclovir-loaded alginate-gellan gum microbeads exhibited comparatively smaller average particle sizes (0.54 ± 0.02 to 0.71 ± 0.03 mm) than those of acyclovir-loaded alginate-xanthan gum microbeads (0.60 ± 0.02 to 0.82 ± 0.04 mm). Acyclovir-loaded alginate-xanthan gum microbeads exhibited comparatively higher swelling than that of acyclovir-loaded alginate-gellan gum microbeads. A sustained pattern of acyclovir release over 240 min was noticed by these microbeads. Surface morphology analysis of the best microbeads formulation (on the basis of sustained acyclovir release data) was done by scanning electron microscopy (SEM). These kinds of ionotropically-gelled alginate-based microbeads might be advantageous to facilitate enhanced patient compliances with minimal dosing frequency and enhanced oral bioavailability.

Stability and Survivability of Alginate Gum-Coated Lactobacillus rhamnosus GG in Simulated Gastrointestinal Conditions and Probiotic Juice Development

Survivability of probiotics is severely affected by harsh gastrointestinal conditions. In the present study, microbeads of Lactobacillus rhamnosus GG were formulated using alginate (1.5% w/v) and combination of alginate (1.5% w/v) with xanthan gum (0.5% w/v) through an emulsion technique to improve bacterial viability in low pH orange juice and in gastrointestinal conditions. The microbeads were tested for encapsulation efficiency, survivability in bile salt, SGF (simulated gastric juice), SIF (simulated intestinal fluid), and storage stability. Probiotic orange juice was formulated and tested for physicochemical parameters (pH, titratable acidity, and total sugars) and sensorial properties during storage. Gum-coated alginate microbeads (T3) showed higher encapsulation efficiency, i.e., 95.2% compared to alginate microbeads (T2), i.e., 86.85%. Similarly, T3 showed the highest resistance against bile salt (8.50 log CFU/g), SGF (7.95 log CFU/g), and SIF (8.0 log CFU/g) during 80 min exposure compared to T2 and free cells. The viability of gum-coated alginate beads (T3) remained above 107 CFU/g in gastrointestinal conditions and at the end of 21 days storage (8.3 log CFU/mL). All physicochemical parameters of probiotic juice were significantly ( p ≤ 0.05 ) decreased with respect to storage except acidity. In addition, minimal changes in physicochemical parameters were observed in T3 compared to other treatments. Treatment had no significant impact on the sensory characteristics of juice, but storage had a significant effect ( p ≤ 0.05 ) on the sensory characteristics of juice. The alginate gum microbeads improve the survivability of probiotics for targeted delivery. Hence, encapsulated probiotics can be used for functional beverage development to take advantage of their therapeutic benefits.

Development and characterization of sodium alginate-g-poly(acrylic acid-co-2-acrylamido-2-methyl-1-propane sulfonic acid)/locust bean gum microbeads containing nickel ferrite nanoparticles for pH-responsive release of doxorubicin

The development of bioactive agent-loaded polymeric carriers offering pH-responsive has substantial potential value for biomedical applications. In light of this, we have designed pH-responsive polymeric microbeads as a vehicle for applications involving the drug delivery. At first, sodium alginate (SA) is grafted with acrylic acid and 2-acrylamido-2-methyl-1-propane sulfonic acid (AMPS) to generate SA-g-(AA-Co-AMPS). Next to functionalise NiFe2O4 nanoparticles with amino groups, nickel ferrite nanoparticles are treated with diethylene triamine and amine-nickel ferrite nanoparticles (ANiFe-NPs) are generated. Finally, we used the gelation ionic technique to develop microbeads using SA-g-(AA-Co-AMPS), locust bean gum (LBG), and ANiFe-NPs. By using FTIR, XRD, SEM, TEM, TGA, and DSC, the amino-nickel ferrite nanoparticles, SA-g-(AA-Co-AMPS), and microbeads were characterised. At pH 7.4 and 1.2, using doxorubicin (DOX) as a model agent in vitro drug release studies were conducted and the findings showed that the synthesized microbeads were proper for gastrointestinal drug administration. The developed microbeads were tested on MCF-7 cells and generated a considerable amount of reactive oxygen species (ROS), had a significant cytotoxicity effect on MCF-7 cells. The generated microbeads warrant further development and optimization to mediate pH-responsive drug release carriers.

PREPARATION AND EVALUATION OF GELLAN GUM-LINSEED GUM BLEND MICROBEADS FOR SUSTAINED RELEASE OF ACECLOFENAC

Objective: The objective of the current investigation was to design aceclofenac encapsulated microbeads using gellan gum and linseed gum blends following ionotropic gelation by trivalent Al3+-ions as cross-linking agent. Methods: Various formulation parameters like polymer-polymer blend (gellan gum and linseed gum), proportion and concentration of aluminium chloride (i.e., cross-linker) were considered for preparation of different formulations. In vitro aceclofenac release from these microbeads was performed in 0.1 N HCl (pH 1.2) for a preliminary 2 h, and after this period, it was continued in phosphate buffer (pH 7.4) for the next 6 h (a total of 8 h). Results: These gellan gum-linseed gum microbeads of aceclofenac exhibited drug encapsulation efficiency of 27.70 ± 0.42 to 74.27±2.57 % and average sizes of gellan gum-linseed gum microbeads were ranged 739.57 ± 22.70 to 968.07 ± 42.24 µm. The release of drug (in vitro) from these gellan gum-linseed gum microbeads of aceclofenac demonstrated a sustained pattern of drug-releasing (over 8 h). Conclusion: These gellan gum-linseed gum microbeads can be used as an effectual option of polymeric carrier matrices for sustained release.

Preparation and evaluation of sustained release dosage forms for posttransplant care

Aim: The purpose of the study was to prepare and characterize microbeads for oral sustained release of tacrolimus. Design, methodology, and approach: Tacrolimus-based microbeads were developed by ionic gelation method. Xanthan gum, chitosan, and sodium alginate were used as polymers for aqueous internal phase using calcium chloride as a cross-linking agent. The microbeads were evaluated for morphologic features by scanning electron microscopy, percentage yield, drug entrapment, and in vitro drug release. Findings and implications: Microbeads were examined for the effects of various variables in formulation process. The cross-linking reaction between sodium alginate and calcium chloride for being converted into calcium alginate in the formulation process was used in the microencapsulation of tacrolimus core material. The results showed the compatibility of the drug with the polymers in the formulation as observed in Fourier-transform infrared spectroscopy studies. The formulated microbeads showed high percentage yield and drug entrapment efficacy and the optimized formulation showed a delayed release effect following zero-order mechanism of release. Conclusion: Ionotropic gelation method was found to be a suitable method for preparing tacrolimus microbead-sustained-release drug delivery system. Chitosan and xanthan gum polymers showed potential in aiding the formulation of sustained release tacrolimus microbeads. Xanthan gum is soluble in water and confers high viscosity at low concentrations. The molecular weight of xanthan gum is more than the chitosan polymer which leads to better sustained release of microbeads prepared with xanthan gum compared to chitosan microbeads. Both chitosan and xanthan gum microbeads followed zero-order-release kinetic models.

Enhanced biodegradation of hydrocarbons by Pseudomonas aeruginosa-encapsulated alginate/gellan gum microbeads

Pseudomonas aeruginosa-encapsulated alginate/gellan gum microbeads (PAGMs) were prepared at the condition of 10 g/L alginate, 1 g/L gellan gum, and 2.57 mM calcium ions, and investigated for the biodegradation of a diesel-contaminated groundwater. The degradation of diesel with PAGMs reached 71.2% after 10days in the aerobic condition, while that of suspended bacteria was only 32.0% even after 30days. The kinetic analysis showed that PAGMs had more than two-order higher second-order kinetic constant than that of the suspended bacteria. Interestingly, the degradation of diesel was ceased due to the depletion of the dissolved oxygen after 10 day in the PAGM reactor, but the microbial degradation activity was immediately restored after the addition of oxygen to 10.5 mg/L. The change in ATP concentration and the viability of bacteria showed that the microbial activity in PAGMs were maintained (66.4%, and 84.3%, respectively) even after 30days of experiment with PAGMs due to the protective barrier of the microbeads, whereas those of suspended bacteria showed significant decrease to 6.2% and 14.4% of initial value, respectively, due to the direct contact to toxic hydrocarbons. The results suggested that encapsulation of bacterial cells could be used for the enhanced biodegradation of diesel hydrocarbons in aqueous systems.

Production of whey protein isolate – gellan microbeads for encapsulation and release of flaxseed bioactive compounds

Production of 1.5% (w/v) whey protein isolate (WPI) – 0.1, 0.3 or 0.5% (w/v) gellan gum microbeads from extrusion of the oil-in-water (O/W) emulsions into a 0.56% (w/v) calcium chloride (CaCl2) solution was evaluated to encapsulate flaxseed oil (15% v/v) and protein hydrolysate (FPH) (0, 0.25 or 0.5% w/v). Microgels resistance and controlled release of oil and FPH were also investigated. Microscopic images showed few free oil droplets and a prevailing presence of gellan on the external surface of the microbeads, indicating that oil and FPH were encapsulated. Microbeads produced at higher gellan concentrations (0.3 or 0.5% w/v) showed a more regular and spherical morphology. However a significant decrease in microbeads size (from ∼55 μm to ∼50 μm) and an increase in the polydispersity were observed with the FPH addition, which can be a consequence of the formation of a more dense biopolymers network. FPH presence (0.25% w/v) decreased the viscosity and shear thinning behavior of microbeads suspensions (10–90% w/v), which could be partly attributed to the smaller size of particles. The microbeads suspensions were stable at different salt concentrations (0.56, 1.11 or 2.22% w/v) regarding their shape, not releasing the encapsulated oil. 1.5% (w/v) WPI – 0.3% (w/v) gellan microbeads were resistant to simulated gastric conditions, but did not resist to intestinal conditions. Our results show that these microgels are adequate to encapsulate bioactive compounds to be released in the small intestine, passing intact in the stomach, which makes the process attractive in order to maintain the bioavailability and functionality of such compounds.

Zinc alginate-carboxymethyl cashew gum microbeads for prolonged drug release: Development and optimization

Isoxsuprine HCl-loaded microbeads using sodium alginate (SA)-carboxymethyl cashew gum (CMCG) polymer-blends were developed through ionotropic-gelation technique using ZnSO4 as cross-linker. Effects of polymer-blend ratio and cross-linker concentration on drug encapsulation efficiency (DEE) and cumulative drug release at 7h (R7h) were optimized by 32 factorial design. Optimized microbeads were of excellent combination of high DEE (79.92±2.51%) and suitable sustained drug release pattern over a prolonged period of 7h (58.67±2.26%). The microbead surface morphology was analyzed by SEM. The physical state of isoxsuprine HCl within the optimized microbead matrix was analyzed by FTIR and DSC. In vitro isoxsuprine HCl release from alginate-CMCG microbeads in phosphate buffer (pH, 6.8) showed prolonged sustained drug release and Korsmeyer-Peppas model (R2=0.9959–0.9992) over 7h.

Transport of Gellan Gum Microbeads in Soil Columns of Various Grain Size Distributions

AbstractThe transport of gellan gum microbeads as potential cell carriers was investigated in horizontal columns packed with different grain size classes of gravel (2–16 mm) and sand (0.25–2 mm). A suspension of microbeads was pulsed into each column for 6 h, followed by injection of water for 42 h. In general, the total amount of microbeads travelling across a given section of the column increased with injection time but decreased towards the column outlet, varying as a direct function of grain size. The results of this study demonstrate the feasibility of the transport of gellan gum microbeads through medium sand to medium gravel across distances up to 110 cm.

Transport of gellan gum microbeads through sand: an experimental evaluation for encapsulated cell bioaugmentation

Transport of 10–40 μm gellan gum microbeads was studied in horizontal sand columns to evaluate the feasibility of using gel-encapsulated bacteria for bioaugmentation of contaminated aquifers. Three 5.2×110 cm columns were packed with sand (column A: 0.5–2 mm, column B: 0.25–2 mm, and column C: 0.125–2 mm). Microbeads in artificial groundwater were injected at 0.5 l h −1 during intermittent 12-h periods. Breakthrough of microbeads increased with injection time, varying as a descending function of travel distance. After 72 h of injection, about 75% of injected microbeads were dispersed across a 5–110 cm distance from the inlet in column A, compared to 78% across a 5–50 cm in column B, and 76% across a 5–20 cm in column C. The wider dispersion of microbeads across the length of column A, compared to those observed in columns B and C, suggests a higher potential for the formation of a uniform bioactive zone of encapsulated cells across a sandy aquifer with such grain size distribution and hydrodynamic properties.

Production of size-controlled gellan gum microbeads encapsulating gasoline-degrading bacteria

Controlling the mean diameter of polymeric carriers is crucial to the successful application of encapsulated cells for in situ bioaugmentation of contaminated aquifers. The cell carriers should be small enough to be transported through a granular soil matrix, thus an emulsification-internal gelation technique for production of cell-encapsulating gellan gum microbeads is proposed. Mean diameter and size distribution of microbeads were investigated as a function of the water-in-oil emulsion parameters. The mean diameter of the microbeads ranged from 12 to 135 μm, varying as a descending function of the stirring rate (1000–5500 rpm) and emulsifier concentration (0–0.20% w/w), and as an ascending function of the disperse phase volume fraction (0.08–0.25). A bacterial consortium encapsulated within the microbeads (23 μm mean diameter) showed improved biodegradation activity in the removal of gasoline (400 mg L −1), as compared to free cells. A high degree of repeatability in the microbead formation process and particle size measurements was demonstrated. The results of this study suggest that the emulsification process can potentially be used for the large-scale production of controlled-diameter gellan gum-encapsulated cell microbeads for subsurface bioremediation applications.