Sodium Alginate Concentration Research Articles

Design and Synthesis of P(AAm-co-NaAMPS)-Alginate-Xanthan Hydrogels and the Study of Their Mechanical and Rheological Properties in Artificial Vascular Graft Applications.

Cardiovascular diseases (CVDs) are the number one cause of mortality among non-communicable diseases worldwide. Expanded polytetrafluoroethylene (ePTFE) is a widely used material for making artificial vascular grafts to treat CVDs; however, its application in small-diameter vascular grafts is limited by the issues of thrombosis formation and intimal hyperplasia. This paper presents a novel approach that integrates a hydrogel layer on the lumen of ePTFE vascular grafts through mechanical interlocking to efficiently facilitate endothelialization and alleviate thrombosis and restenosis problems. This study investigated how various gel synthesis variables, including N,N'-Methylenebisacrylamide (MBAA), sodium alginate, and calcium sulfate (CaSO4), influence the mechanical and rheological properties of P(AAm-co-NaAMPS)-alginate-xanthan hydrogels intended for vascular graft applications. The findings obtained can provide valuable guidance for crafting hydrogels suitable for artificial vascular graft fabrication. The increased sodium alginate content leads to increased equilibrium swelling ratios, greater viscosity in hydrogel precursor solutions, and reduced transparency. Adding more CaSO4 decreases the swelling ratio of a hydrogel system, which offsets the increased swelling ratio caused by alginate. Increased MBAA in the hydrogel system enhances both the shear modulus and Young's modulus while reducing the transparency of the hydrogel system and the pore size of freeze-dried samples. Overall, Hydrogel (6A12M) with 2.58 mg/mL CaSO4 was the optimal candidate for ePTFE-hydrogel vascular graft applications due to its smallest pore size, highest shear storage modulus and Young's modulus, smallest swelling ratio, and a desirable precursor solution viscosity that facilitates fabrication.

Thermo‐mechanical properties and optimization of sodium alginate as a polymer backbone substrate for biosensor application

AbstractThis study was aim to optimize the formulation of the sodium alginate biosensor substrate with incorporation of sodium alginate (1%‐6%(w/v)) as a polymer backbone and glycerol (10–50 wt%) as a plasticizer. The effect of their interaction on film's tensile strength (TS) and elongation at break (EB) were analyzed via response surface methodology‐central composite design (RSM‐CCD). The optimum parameter of the films for the maximum TS was at 1.90%(w/v) of sodium alginate and 17 wt% of glycerol and for maximum EB was at 4.89%(w/v) of sodium alginate and 49.65 wt% of glycerol. The optimum parameter of the films had revealed the better TS was at lower sodium alginate content and better EB was at higher glycerol content. In terms of thermal stability, the thermal decomposition temperature (Tonset) of sodium alginate decreased with the incorporation of glycerol.

Effectiveness of sodium alginate-based coating on the preservation of Da xanh pomelo fresh-cut

Pomelo (Citrus maxima (Burm. f.) Merr) fresh cut has a highly sensitive fruit and has a short shelf life after peeling. The fruits represent high potentials for local consumption and international export. The objective of the study was to focus on the effects of different concentrations of sodium alginate (1%, 1.5% and 2%) combined with fixed concentrations of calcium chloride (2%) and ascorbic acid (2.5%) to biologically active compounds and allowable microbial content on the surface pomelo fresh cut slices. The results showed that the presence of coating has improved several important quality parameters of the fruit. Specifically, the combination of AL (2%) + AA (2.5%) + calcium chloride (2%) Ascorbic acid (AA) has effectively maintained the total polyphenol content and the total ascorbic acid of the pomelo slice samples, thus exhibiting higher DPPH scavenging activity, as compared to control samples. Furthermore, the pomelo coated with alginate showed good conditions for consumption with minimal microbial degradation and describe good acceptance after 6 days of storage.

Physicochemical and digestion properties of fish oil and anthocyanins co-encapsulated W/O/W emulsion reinforced with alginate

W/O/W double emulsion systems offer the ability to co-deliver water-soluble and oil-soluble bioactives, making them a promising choice for multifunctional delivery applications. This study focused on the development of a whey protein isolate-based W/O/W emulsion encapsulating fish oil and anthocyanins, with the addition of sodium alginate (SA) into the external aqueous phase. The physicochemical properties, emulsion stability, anthocyanins encapsulation efficiency (EE), and anthocyanins release during simulated gastrointestinal digestion were studied. The results indicated that the physical stability of W/O/W emulsions improved with increasing SA, attributed to the higher viscosity and the protective coating of SA on the WPI-stabilized interface. However, the EE of anthocyanins in SA-reinforced W/O/W emulsions was found to be lower. Excessive SA concentration, such as 1.0%, was observed to be unfavorable to maintaining the internal W1/O interface integrity. Overall, the double emulsion structure effectively regulated the release of anthocyanins throughout the digestion process. The study concluded that W/O/W emulsions containing 0.75% SA achieved optimal stability and controlled-release characteristics. These findings offer valuable insights into fabricating double emulsions for multifunctional delivery purposes, showcasing their potential applications in the food and pharmaceutical industries.

Construction of a pectin/sodium alginate composite hydrogel delivery system for improving the bioaccessibility of phycocyanin

In this study, different concentrations of sodium alginate were compounded with pectin and phycocyanin to co-prepare composite hydrogel spheres (HP-PC-SA 0.2 %, 0.6 %, 1.0 %, 1.4 %) to evaluate the potential of the composite hydrogel spheres for the application as phycocyanin delivery carriers. The hydrogel spheres' physicochemical properties and bioaccessibility were assessed through scanning electron microscopy, textural analysis, drug-carrying properties evaluation, and in vitro and in vivo controlled release analysis in the gastrointestinal environment. Results indicated that higher sodium alginate concentrations led to smaller pore sizes and denser networks on the surface of hydrogel spheres. The textural properties of hydrogel spheres improved, and their water-holding capacity increased from 93.01 % to 97.97 %. The HP-PC-SA (1.0 %) formulation achieved the highest encapsulation rate and drug loading capacity, at 96.87 % and 6.22 %, respectively. Within the gastrointestinal tract, the composite hydrogel's structure significantly enhanced and protected the phycocyanin's digestibility, achieving a bioaccessibility of up to 88.03 %. In conclusion, our findings offer new insights into improving functionality and the effective use of phycocyanin via pectin-based hydrogel spheres.

Structure Effects on Swelling Properties of Hydrogels Based on Sodium Alginate and Acrylic Polymers.

Hydrogels based on sodium alginate (SA) and partially neutralised poly(acrylic acid) were obtained by radical polymerisation. The hydrogels were cross-linked with N,N'-methylenebisacrylamide (MBA), simultaneously grafting the resulting polymer onto SA. The findings of the FTIR spectroscopy showed that all of the hydrogels were effectively synthesized and sodium alginate was chemically bonded with the poly(sodium acrylate) matrix. DSC analysis of the melting heat and glass transition parameters indicated that the hydrogel structure had changed as a result of the cross-linking process. Sodium alginate and MBA were tested at different concentrations to determine how they affected the hydrogel properties. A very high content of the biopolymer, i.e., sodium alginate, was used in our research, up to 33 wt%. This resulted in durable and stable hydrogels with a very high ability to uptake water, comparable to hydrogels based on synthetic polymers only. The ability to swell is inversely proportional to the quantity of MBA present. By increasing the amount of sodium alginate in the hydrogel, the ability of the hydrogel to absorb water is reduced. However, water uptake remains relatively high at 350 g·g-1, even for the hydrogel with the highest SA content.

Immobilization of Coprinus comatus with magnetic alginate hydrogel microsphere for improving the antioxidant activity of fermentation products

Coprinus comatus is an edible mushroom and its fermented product possesses antioxidant activity. In this study, to further enhance the antioxidant activity and improve the reusability of the strain, calcium alginate hydrogel was used as the carrier for embedding and immobilizing Coprinus comatus. The effects of CaCl2 concentration, sodium alginate concentration, microsphere diameter, and the amount of magnetic particle on the antioxidant activity of fermented products were investigated. The results showed that the magnetic immobilized microsphere prepared by 2.50% CaCl2, 2.00% sodium alginate and 0.50% Fe3O4 had the best fermentation antioxidant activity (EC50 was 0.43 ± 0.01 mg/mL) when the diameter was 5 mm, which increased by 24.56% compared to the initial activity. Besides, the microsphere showed strong reusability, the antioxidant activity was still better than the free strain after being used five times. This study not only enhanced the antioxidant activity of Coprinus comatus fermented product through immobilization, but also provided an effective method for microbial fermentation.

Process optimization of Cd2+ removal with Tetradesmus Obliquus-immobilized Algal Beads

In this study, calcium alginate-immobilized microalgae beads were utilized for treating Cd2+-containing wastewater by optimizing the algal species, the preparation conditions of immobilized beads, and the Cd2+ treatment conditions to enhance treatment efficiency. The results revealed that under optimal preparation conditions with a CaCl2 concentration of 3 % and a sodium alginate concentration of 2 %, the removal rate of Cd2+ reached 94.99 % after 3 h of adsorption when 4 g of immobilized Tetradesmus obliquus algal beads were added to a 20 mg/L Cd2+ solution. Additionally, under optimal removal conditions at pH=6, with immobilized Tetradesmus obliquus algal beads as the adsorbent and a dosage of 6 g of immobilized algal beads added to a solution with an initial Cd2+ concentration of 15 mg/L, the Cd2+ removal rate reached 99.85 % after 4 h of adsorption, surpassing that of suspended microalgae and blank algal beads. The adsorption process followed the pseudo-second-order kinetic model and the Langmuir adsorption isotherm model. FTIR analysis indicated that functional groups such as O-H, CO, C-O, C-N, among others, might play a role in the adsorption process. After five adsorption-desorption cycles, the adsorption capacity decreased by only 10 %. This study demonstrated that immobilized Tetradesmus obliquus algal beads is an efficient and renewable and recyclable adsorbent.

Effects of Sodium Alginate and Calcium Chloride on Fungal Growth and Viability in Biomass-Fungi Composite Materials Used for 3D Printing.

To combat climate change, one approach is to manufacture products from biomass-fungi composite materials instead of petroleum-based plastics. These products can be used in packaging, furniture, and construction industries. A 3D printing-based manufacturing method was developed for these biomass-fungi composite materials, eliminating the need for molds, and enabling customized product design. However, previous studies on the 3D printing-based method showed significant shrinkage of printed samples. In this paper, an approach is proposed to reduce the shrinkage by incorporating ionic crosslinking into biomass-fungi composite materials. This paper reports two sets of experiments regarding the effects of sodium alginate (SA) and calcium chloride (CaCl2) on fungal growth and fungal viability. The first set of experiments was conducted using Petri dishes with fungi isolated from colonized biomass-fungi material and different concentrations of SA and CaCl2. Fungal growth was measured by the circumference of fungal colonies. The results showed that concentrations of SA and CaCl2 had significant effects on fungal growth and no fungal growth was observed on Petri dishes with 15% CaCl2. Some of these Petri dishes were also observed under confocal microscopy. The results confirmed the differences obtained by measuring the circumference of fungal colonies. The second set of experiments was conducted using Petri dishes with biomass-fungi mixtures that were treated with different concentrations of SA and exposure times in a CaCl2 (crosslinking) solution. Fungal viability was measured by counting colony-forming units. The results showed that the addition of the SA solution and exposure times in the crosslinking solution had statistically significant effects on fungal viability. The 2SA solution was prepared by dissolving 2 g of SA in 100 mL of water, the 5SA solution was prepared by dissolving 5 g of SA in 100 mL of water, and the crosslinking solution was prepared by dissolving 5 g of CaCl2 in 100 mL of water. The results also showed that fungal viability was not too low in biomass-fungi mixtures that included 2SA solution and were exposed to the crosslinking solution for 1 min.

Plant-based delivery systems for controlled release of hydrophilic and hydrophobic active ingredients: Pea protein-alginate bigel beads

Oral delivery systems for nutrients and nutraceuticals are required for personalized nutrition applications. In some applications, these delivery systems need to encapsulate both hydrophilic and hydrophobic bioactive agents. In this study, bigel beads (2 mm) were prepared using pea protein (PP) and sodium alginate (SA) to form the hydrogel phase, and glyceryl monostearate and soybean oil to form the oleogel phase. The hydrogel phase was crosslinked by using Ca2+ ions to form electrostatic bridges between the alginate molecules. The bigel beads had an oil-in-water type structure consisting of an oleogel dispersed phase within a hydrogel continuous phase. These beads were used to encapsulate and control the release of model hydrophobic (curcumin) and hydrophilic (epigallocatechin gallate) nutraceuticals. The textural and microstructural characteristics of the bigel beads were evaluated by dynamic shear rheology, textural profile analysis, cryo-electron microscopy, and fluorescence confocal microscopy. As the concentration of SA increasing from 0.2 to 1.0%, the hardness of bigel beads increased from 306.75 g to 792.40 g. In vitro digestion experiments showed that most of the nutraceuticals were released in the small intestine, rather than the stomach. Nutraceutical release could be controlled by manipulating bead composition, with the extent of nutraceutical release decreasing with increasing alginate concentration. The bigel beads developed in this study could be used as easy-to-swallow carriers for the controlled release of hydrophilic and hydrophobic bioactive ingredients. These kinds of products may be especially useful for people with dysphagia.

Characterization of hydrogel beads constructed from gelatinized lotus rhizome starch and sodium alginate by calcium cross-linking

The purpose of this study was to construct calcium cross-linked gelatinized lotus rhizome starch (LRS)/sodium alginate (SA) hydrogel beads of adjustable quality and to reduce the digestibility of gelatinized starch. LRS was mixed with SA, gelatinized by heating and subsequently cross-linked with Ca2+ to form hydrogel beads. The digestibility of the gelatinized LRS could be adjusted by changing the dose of SA in the hydrogel beads. When the LRS/SA ratio was 4/6, the rapidly digested starch (RDS) content in the beads was reduced by 26.9% compared with gelatinized LRS alone, whereas the slowly digested starch (SDS) and resistant starch (RS) contents increased by 12.3-fold and 2.3-fold, respectively. In addition, the water distribution in the Ca2+-crosslinked LRS/SA hydrogel bead samples also showed an SA dose dependence. With increasing SA concentration, the ability of the hydrogel beads to immobilize water increased. The diffusion of Ca2+ into the interpenetrating polymer network that was prepared with gelatinized LRS and SA gradually resulted in gelation dominated by ion bonds, leading to the heterogeneous microstructure of the hydrogel beads, which also involved intermolecular hydrogen bond interactions. Overall, the present study suggested a strategy for developing novel LRS hydrogel bead systems for quality control and gelatinized starch digestibility downregulation by adjusting the SA dose, which provided insights for the innovation of personalized and convenient starchy products in the food industry.

Developing and Evaluating a Novel Drug Delivery System, Calcium-Alginate Beads loaded with Valsartan

Valsartan is one of the most common drugs used by chronic patients in the management of hypertension, heart failure, and diabetic nephropathy. This present study was conducted with the aim of formulating a long-acting pharmaceutical form by preparing millimeter dimensions’ solid polymeric beads using the Ionotropic Gelation technique by using the polymer “Alginate Sodium” (SA), and Calcium Chloride CaCl2 as a cross-linking agent. Prepared valsartan beads succeeded in the possibility of decreasing dose administration and therefore, reduced immediate release side effects of conventional forms of Valsartan. Valsartan beads were studied using different concentrations of Sodium Alginate and Calcium Chloride to select the optimal formula and then were compared with locally marketed film-coated tables containing Valsartan. The formula (SA 3%, CaCl2 10%) was chosen after conducting several physiochemical tests such as shape and dimensions, swelling index, entrapment efficiency, in vitro drug release, and FTIR. FTIR test showed no chemical bonding between Valsartan and other excipients. Selected beads achieved a high percentage of swelling in phosphate buffer solution pH=6.8. Entrapment efficiency was also high at about 80%. Prepared beads followed the Korsmeyer-Peppas release mechanism, and eventually obtained extended-release beads which slowed drug release for 24h, Compared with the film-coated tablets, the in vitro release of valsartan expired after only one hour.

Non-destructive monitoring and prediction of fouling by organic matters and residual anionic coagulant during membrane process

Physical fouling characteristics on silicon carbide (SiC) membranes induced by various organic matter compounds vary depending on the presence of calcium ions (Ca2+). Both destructive techniques (morphological surface analysis) and non-destructive techniques (fouling properties monitoring) were used to determine the fouling mechanisms and behavior during the membrane filtration systems. Destructive analysis and a modified Hermia model were employed to assess the fouling mechanisms. Fouling behavior was also analyzed through non-destructive monitoring techniques including optical coherence tomography (OCT) and three-dimensional laser scanning confocal microscopy (3D-LSM). At concentrations of 10, 30, and 100 mg/L without Ca2+, the flux decreased by 57–95% for humic acid (HA) and anionic polyacrylamide (APAM). APAM exhibited a notable removal rate of up to 56% without Ca2+. At concentration of 10, 30, and 100 mg/L in the absence of Ca2+, the flux decreased by 6–8% for sodium alginate (SA). However, the addition of Ca2+ led to a reduction in the flux for SA by up to 91% and resulted in a removal rate of 40%. Furthermore, addition of Ca2+ led to an alteration of the fouling characteristics of HA and SA. In the case of HA, higher concentrations resulted in elevated thickness and roughness with correlation coefficients of 0.991 and 0.992, respectively. For SA, increased SA concentration led to a thicker (correlation coefficient of 0.999) but smoother surfaces (correlation coefficients of 0.502). Monitoring of these physical characteristics of the fouling layer through non-destructive analysis is crucial for effective fouling management, optimization of the system performance and extending the lifespan of the membrane. By continuously assessing the fouling layer thickness and surface roughness, we expect to be able to provide insights on the fouling behavior, identify trends, that can help scientists and engineers to make informed decisions regarding fouling control strategies in future.

Optimization of Ink Composition and 3D Printing Process to Develop Soy Protein-Based Scaffolds.

Inks based on soybean protein isolate (SPI) were developed and their formulations were optimized as a function of the ink heat treatment and the content of other biopolymers to assess the effects of protein-polysaccharides and protein-protein interactions. First, the rheological behavior of the inks was analyzed in relation to the polyvinyl alcohol (PVA) concentration employed (20, 25, and 30 wt%) and, as a result of the analysis, the ink with 25 wt% PVA was selected. Additionally, sodium alginate (SA) and gelatin (GEL) were added to the formulations to improve the viscoelastic properties of the inks and the effect of the SA or GEL concentrations (1, 2, and 3 wt%) was studied. All inks showed shear thinning behavior and self-supporting abilities. Among all the 3D printed scaffolds, those with higher SA (3 wt%) or GEL (2 and 3 wt%) content showed higher shape fidelity and were selected for further characterization. Texture profile analysis demonstrated that the scaffolds prepared with previously heat-treated inks containing 3 wt% GEL showed the highest strength. Additionally, these scaffolds showed a higher water-uptake capacity profile.

Preparation, characterization and in vitro digestion of jujube polysaccharide microcapsules

The preparation of jujube polysaccharide microcapsules was investigated in this study. Microcapsule technology was employed to encapsulate jujube polysaccharides, effectively isolating them from external substances and facilitating their smooth passage through the intestinal tract. The objective was to control the release and prolong the release time of the polysaccharides. Additionally, we evaluated the characteristics of these microcapsules and their in vitro solubility and digestive behaviors. The findings demonstrated that the optimal preparation conditions, measured by the encapsulation efficiency, included a sodium alginate concentration of 4% (w/v), a core-to-wall ratio of 1:6, a calcium chloride concentration of 3% (w/v), and a chitosan concentration of 0.5% (w/v). The factors influencing the process ranked in the following order: core-to-wall ratio > sodium alginate concentration > chitosan concentration > CaCl2 concentration. The microcapsules produced under the optimal conditions exhibited a remarkable encapsulation efficiency of 97.29%. The characterization and analysis of the jujube polysaccharide microcapsules confirmed their successful encapsulation, uniform particle size distribution, and robust thermal stability. In addition, swelling and in vitro release trials demonstrated that the jujube polysaccharide microcapsules exhibit excellent swelling characteristics and consistent and prolonged release patterns. These distinct characteristics are anticipated to significantly impact functional food and medicine.

Processing of Whole Kernel Tapioca Pearl and Milk Tea BOBA of Fresh Highland Barley: Optimization of Processing Parameters and Quality Evaluation.

Fresh highland barley is difficult to store, leading to a lack of commercial products. To address these problems, the research investigated the effect of different heat treatments (steaming <SFB>, microwaving <MFB>, baking <BFB>, and cooking <CFB>) on the quality of fresh highland barley, and used pretreated fresh highland barley as material, combined with the milk tea market, to design and optimize the preparation process of fresh highland barley tapioca pearl and milk tea BOBA. The results showed that the different heat treatments reduced the content of ash and starch significantly, and SFB and MFB decreased the digestibility of fresh highland barley (P < 0.05). In particular, SFB had a significantly higher overall score for fresh barley than the other treatments, with the highest sensory evaluation for aroma, elasticity, and the overall taste of the grain, and the eGI value was the lowest (58.64). The optimal preparation process of fresh highland barley tapioca pearl and milk tea BOBA was designed and optimized by the L9(34) orthogonal test. The optimal tapioca pearl formula contained the following: apioca starch content of 36%, cooking time of 2.5 min, and erythritol stevia content of 1.5%. The optimal milk tea BOBA formula contained the following: sodium alginate content of 1.3%, erythritol stevia content of 0.6%, and calcium lactate content of 2.2%. This not only improves the comprehensive utilization rate of fresh highland barley, but also provides the accessory food, ensuring a lower eGI and increasing the healthiness and diversity of milk tea.

Role of gamma-irradiated sodium alginate on growth, physiological and active components of iceberg lettuce (Lactuca sativa) plant

BackgroundOne of the most widely recognized biostimulators of plant development; is oligoalginate, which regulates the biological processes of plants and was used in horticultural fields as a plant growth regulator. The plan of the current research was to study, however, the foliar application of un-irradiated and irradiated Na-alginate (UISA and ISA) to improve the growth, physiological activity, and other active components of the Egyptian iceberg lettuce plant. Degraded Na-alginate is equipped with exposure of sodium alginate in its solid state to gamma-rays at different dose levels (0.0, 25, 50, 75, and 100 kGy). The characterization of the oligo-alginates achieved by γ-radiation deprivation at different dose levels was performed by FTIR, XRD, TGA, SEM, and TEM. Different concentrations of irradiated sodium alginate at dose levels of 100 kGy (200, 400, 600, and 800 ppm, as well as deionized water used as a control) were sprayed with a hand sprayer every week after transplanting the iceberg lettuce seedlings in the field until the harvest stage. Morphological traits were evaluated, as well as pigments, ascorbic acid, phenols, flavonoids, soluble proteins, and antioxidant activity.ResultsIrradiated Na-alginate resulted in the depolymerization of Na-alginate into small molecular-weight oligosaccharides, and the best dose to use was 100 kGy. Certain chemical modifications in the general structure were observed by FTIR analysis. Two absorbed bands at 3329 cm−1 and 1599 cm−1, were recognized that are assigned to O–H and C-O stretching, respectively, and peaks achieved at 1411 cm−1 represent the COO-stretching group connected to the sodium ion. The peak obtained at 1028 cm−1 was owing to the stretching vibration of C-O. The results of TGA provided that the minimum weight reminder was in the ISA at 100 kGy (28.12%) compared to the UISA (43.39%). The images of TEM pointed out that the Na-alginate was globular in shape, with the particle distribution between 12.8 and 21.7 nm in ISA at 100 kGy. Irradiated sodium alginate caused a noteworthy enhancement in the vegetative growth traits (leaf area, stem length, head weight, and leaf number). By spraying 400 ppm, ISA showed a maximum increase in total pigments (2.209 mg/g FW), ascorbic acid (3.13 mg/g fresh weight), phenols (1.399 mg/g FW), flavonoids (0.775 mg/g FW), and antioxidant activities (82.14. %). Also, there were correlation coefficients (R values) between leaf area, stem length, head weight, and leaf number values with total pigment content, antioxidant activity, total soluble proteins, and ascorbic acid.ConclusionsThe outcomes of the recent investigation demonstrated that the application of spraying irradiated Na-alginate (100 kGy) resulted in an improvement of the considered characters.

Optimization of Malabar Nut (Justicia adhatoda L.) Leaves’ Phenolic Compounds by Alginate Emulsion-gelation Approach using Response Surface Methodology

Background: The encapsulation technique is an effective method for coating bioactive molecules and protecting them against various technological treatment conditions during production processing. Objective: The aim of this study was to optimize the encapsulation conditions of phenolic compounds extracted from Malabar nut (Justicia adhatoda L.) leaves by alginate emulsion-gelation approach using response surface methodology Methods: The ionotropic gelation method was used to encapsulate the phenolic compounds of Malabar nut (Justicia adhatoda L.) leaves. The optimization of this phenolic compounds encapsulation was carried out using response surface methodology through Box˗Behnken design. Four parameters with three levels (-1, 0, +1) were chosen including sodium alginate concentration (2 – 3 - 4%), calcium chloride concentration (4 - 6 - 8%), plant extract-alginate solution ratio (0.02 – 0.11 - 0.2 mg/ml), and gelation time (5 – 12.5 - 20 min). of the total phenolic and flavonoid contents encapsulation efficiency was assessed. Likewise, the antioxidant activity was evaluated using ferric-reducing power (FRP) and free radical scavenging activity (DPPH). Results: The results of response surface methodology analysis using Box˗Behnken design showed that the optimal encapsulation conditions were 3.11% for alginate concentration, 5.74% for calcium chloride concentration, 0.1 mg/ml for the plant extract-alginate solution ratio, and 10.80 min for gelation time. Under these conditions, the optimum values of total phenolic and flavonoid encapsulation efficiency were 86.17% and 75.69%, respectively, 126.75 mg AAE/100 g for ferric reducing power and 97.29% for DPPH. The experimental and prediction results have expressed a high significant level for all responses. Conclusion: The method revealed the validity of elaborated models through response surface methodology optimization processes for phenolic antioxidants encapsulation of Malabar nut (Justicia adhatoda L.) leaves extract.

Clinical Investigation of Valsartan Sustained-Release Matrix Tablets: Formulation Design and Performance Evaluation

The primary objective of this main study is to develop and assess the sustained-release matrix tablets containing Valsartan, an angiotensin II receptor type 1 antagonist. The powder mixtures underwent a thorough examination of pre-compression parameters and observed angle of repose, bulk density, tapped density, and Carr’s index, all of which exhibited satisfactory results. Following compression, the tablets were subjected to post-compression evaluations, including weight variation, thickness, hardness, friability, drug content, in-vitro dissolution, and stability studies. In-vitro dissolution investigations are conducted over 24 hours, employing 0.1 N HCL for the initial 2 hours and pH 6.8 phosphate buffer for the subsequent 24 hours. Notably, formulations F4 and F7 demonstrated promising dissolution profiles, effectively controlling the release of the drug. These formulations, enriched with higher concentrations of chitosan and sodium alginate in addition to other polymers, successfully sustained the drug release for the entire 24-hour duration. The compatibility of the drug, polymers, and other excipients was meticulously assessed using FT-IR Spectroscopy, affirming the harmonious interaction among these components. Further analysis involved fitting the release data to various mathematical models, including Zero-order, First-order, Higuchi equation, and Korsmeyer-Peppas model, to ascertain the kinetics and mechanisms governing drug release. Results indicated that the drug release adhered to first-order kinetics, with a non-Fickian mechanism prevailing. Stability studies conducted for 3 months provided reassurance regarding the stability of the selected formulations (F4 and F7), bolstering confidence in their potential for sustained release of Valsartan.

FORMULATION AND CHARACTERISATION OF GASTRORETENTIVE IN SITU GEL LOADED WITH GLYCYRRHIZA GLABRA L. EXTRACT FOR GASTRIC ULCER

Objective: The study aimed to formulate and evaluate the gastroretentive in situ gelling system of Glycyrrhiza glabra L. extract to increase the gastric residence time and provide sustained release of the drug, thereby avoiding disadvantages such as frequent dosing, patient non-compliance and low bioavailability. Methods: The in-situ gel was prepared by pH-triggered gelation method by using sodium alginate and gellan gum as polymers, sodium citrate as a crosslinking agent, and calcium carbonate as a floating agent. Formulation and optimization of in situ gels were achieved by 32 factorial design by using Design-Expert Software to determine the influence of independent variables such as concentration of sodium alginate and gellan gum on viscosity, gel strength, the onset of flotation, and drug release at 12 h. Results: The viscosity, gel strength, onset of flotation and drug release at 12h of optimized formulation were found to be 568.89 cps, 42.91 sec, 53.17 sec and 82.69%, respectively. The floating duration of all in-situ gels was found to be more than 12 h. All the formulations showed drug content in the range of 83.55% to 95.28%. The in vitro release profile of the drug extract from all the formulations appeared to follow the Higuchi model, which concludes that the drug release was controlled by diffusion mechanism. The FTIR study indicates no chemical incompatibility between drug extract and other excipients. Conclusion: Hence, a novel gastroretentive in situ gelling system of Glycyrrhiza glabra L. could be prepared for sustained oral delivery to increase patient compliance with reduced dosing frequency and increased residence time of the drug in the stomach.