scholarly journals Probing the release of the chronobiotic hormone melatonin from hybrid calcium alginate hydrogel beads

2020 ◽  
Vol 70 (4) ◽  
pp. 527-538 ◽  
Author(s):  
Marilena Vlachou ◽  
Angeliki Siamidi ◽  
Efstratia Goula ◽  
Panagiotis Georgas ◽  
Natassa Pippa ◽  
...  
Keyword(s):  
Molecular Mass ◽  
Calcium Alginate ◽  
Aqueous Media ◽  
Sleep Onset ◽  
Alginate Beads ◽  
Poor Sleep ◽  
Hybrid Hydrogel ◽  
Hydrogel Beads ◽  
Degradation Properties

AbstractA variety of commonly used hydrogels were utilized in the preparation of calcium alginate beads, which incorporate the chronobiotic hormone melatonin (MLT). The in vitro release of the hormone in aqueous media at pH 1.2 and 6.8 was probed in the conjunction with the swelling of the beads and their thermal degradation properties. It has been found that the release of MLT from the beads was reversibly proportional to the extent of their expansion, which depends on the molecular mass/viscosity of the biopolymers present in the beads; the higher the molecular mass/viscosity of the hydrogels the greater the beads swelling and the less the MLT’s release. Thermogravimetric analysis (TGA) data support the presence of the components in the hybrid hydrogel beads and elucidate their effects on the thermal stability of the systems. Thus, the physicochemical properties of the biopolymers used, along with their stereoelectronic features modulate the release of MLT from the beads, providing formulations able to treat sleep onset related problems or dysfunctions arising from poor sleep maintenance.

N-Acetylserotonin vs Melatonin: In-Vitro Controlled Release from Hydrophilic Matrix Tablets

2019 ◽  
Vol 16 (3) ◽  
pp. 347-352 ◽  
Author(s):  
M. Vlachou ◽  
G. Stavrou ◽  
A. Siamidi ◽  
S. Flitouri ◽  
V. Ioannidou ◽  
...  
Keyword(s):  
Controlled Release ◽  
Selective Serotonin Reuptake Inhibitors ◽  
Sleep Onset ◽  
Matrix Tablets ◽  
Melatonin Receptors ◽  
Solid Matrix ◽  
Poor Sleep ◽  
Prolonged Release ◽  
Hydrophilic Matrix

Background: N-Acetylserotonin (NAS, N-acetyl-5-hydroxytryptamine) is the immediate precursor of the neurohormone melatonin (MT, N-acetyl-5-methoxytryptamine), which regulates sleep and wake cycles. NAS is produced by the N-acetylation of serotonin and is converted to melatonin via the action of Acetylserotonin O-methyltransferase (ASMT). Like melatonin, NAS acts as an agonist on the melatonin receptors MT1, MT2, and MT3. However, as NAS is abundant in specific brain areas, separate from serotonin and melatonin, it may also have discrete central effects. Indicatively, it has been reported that NAS may play a role in the antidepressant effects of Selective Serotonin Reuptake Inhibitors (SSRIs) and Monoamine Oxidase Inhibitors (MAOIs). </P><P> Objective: To decipher the controlled release characteristics of the active substances (NAS and MT) in a quick initial pace, aiming at a satisfactory sleep-onset related anti-depressive profile and prolonged release, thereafter, targeting at coping with poor sleep quality problems. </P><P> Methods: A series of hydrophilic matrix tablets involving as excipients, hydroxypropylmethylcellulose (HPMC) K15M, low viscosity sodium alginate, lactose monohydrate, and polyvinylpyrrolidone (PVP) M.W.: 10.000 and 55.000) was developed and tested at two dissolution media (pH 1.2 and 7.4). </P><P> Results: The results showed that commonly used excipients with different physicochemical properties govern the controlled release of NAS and MT from solid matrix systems. </P><P> Conclusions: We have demonstrated how broadly used excipients affect the in vitro controlled release of NAS and MT from solid pharmaceutical formulations. Currently, we extend our studies on the controlled release of these drugs using various other biopolymers/formulants of different physicochemical characteristics, which will help to highlight the discrete release profiles of NAS and MT.

Calcium alginate beads as a slow-release system for delivering angiogenic molecules In Vivo and In Vitro

1992 ◽  
Vol 152 (2) ◽  
pp. 422-429 ◽  
Author(s):  
Elizabeth C. Downs ◽  
Nancy E. Robertson ◽  
Terry L. Riss ◽  
Marian L. Plunkett
Keyword(s):  
Calcium Alginate ◽  
Slow Release ◽  
Alginate Beads ◽  
Calcium Alginate Beads ◽  
Release System ◽  
Slow Release System

scholarly journals Calcium Alginate and Calcium Alginate-Chitosan Beads Containing Celecoxib Solubilized in a Self-Emulsifying Phase

Scientifica ◽  
2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Lorena Segale ◽  
Lorella Giovannelli ◽  
Paolo Mannina ◽  
Franco Pattarino
Keyword(s):  
Drug Release ◽  
Calcium Alginate ◽  
Aqueous Media ◽  
Mechanical Resistance ◽  
Drug Release Rate ◽  
Good Tool ◽  
Chitosan Beads ◽  
Colon Delivery ◽  
Different Diameters

In this work alginate and alginate-chitosan beads containing celecoxib solubilized into a self-emulsifying phase were developed in order to obtain a drug delivery system for oral administration, able to delay the drug release in acidic environment and to promote it in the intestinal compartment. The rationale of this work was linked to the desire to improve celecoxib therapeutic effectiveness reducing its gastric adverse effects and to favor its use in the prophylaxis of colon cancer and as adjuvant in the therapy of familial polyposis. The systems were prepared by ionotropic gelation using needles with different diameters (400 and 600 μm). Morphology, particle size, swelling behavior, andin vitrodrug release performance of the beads in aqueous media with different pH were investigated. The experimental results demonstrated that the presence of chitosan in the formulation caused an increase of the mechanical resistance of the bead structure and, as a consequence, a limitation of the bead swelling ability and a decrease of the drug release rate at neutral pH. Alginate-chitosan beads could be a good tool to guarantee a celecoxib colon delivery.

scholarly journals Effects of encapsulation matrix on physical properties and germination viability of calcium-alginate encapsulated plbs of Grammatophyllum scriptum

2017 ◽  
Vol 1 (1) ◽  
pp. 36-40 ◽  
Author(s):  
ARI PITOYO ◽  
ENDANG ANGGARWULAN ◽  
IKA ARIZA
Keyword(s):  
Physical Properties ◽  
Calcium Alginate ◽  
Seed Mass ◽  
Synthetic Seed ◽  
Orchid Species ◽  
Optimum Result ◽  
Hydrogel Beads ◽  
Randomized Design ◽  
Completely Randomized Design

Pitoyo A, Anggarwulan E, Ariza I. 2017. Effects of encapsulation matrix on physical properties and germination viability of calcium-alginate encapsulated plbs of Grammatophyllum scriptum. Cell Bio Dev 1: 36-40. Grammatophyllum is a tropical epiphytic orchid commonly found in the moist areas of South-East Asia. Like most orchid species, the genus comprises species with a very small, micro-size seed mass and lacked endosperm.These plants commonly need an in vitro culture for mass propagation and seed germination. Upon germination, their undeveloped-embryos developed a globular mass cells, a protocorm. Occasionally, a structure similar to protocorm arises from tissue other than an embryo, thereby the term protocorm-like body (plb) were introduced. Here, we develop synthetic seed, hydrogel beads encapsulated G. scriptum plbs and possibility to germinate the seed and growth their embedded tissue.The objective of the research was to study the effects of the proportion of encapsulation matrix of G scriptum Bl.Synthetic seed made by complexation of sodium alginate with CaCl2 on physical properties and germination of protocorm-like bodies (plbs) embedded inside the hydrogel. The experiment was designed by a single factor-completely randomized design with the treatments of several combinations of Na-alginate/CaCl2ratios.The result showed that CaCl2 in all concentration except 25 mM formed spherical hydrogel beads in all level concentration of Na-alginate. Alginate in concentration 2% and 3% gave the optimum result represented by maximum germination index 100%.The formation of the new plbs varied among different explants even in single explant.The time of germination of each synthetic seeds was varied from 2 weeks until eight weeks after encapsulation.In conclusion, physical properties have no significant barrier for developing plbs to emergencies through penetration encapsulation matrix.

scholarly journals Preparation and Evaluation of Controlled Release Calcium Alginate Beads Containing Mefenamic Acid

2019 ◽  
pp. 9-16
Keyword(s):  
Mefenamic Acid ◽  
Calcium Alginate ◽  
In Vitro Release ◽  
Alginate Beads ◽  
Release Profile ◽  
Calcium Alginate Beads ◽  
Eudragit S100 ◽  
Percentage Yield ◽  
Preparation And Evaluation

The present study was designed to investigate the effects of different variables on the release profile of mefenamic acid from calcium alginate beads formulated using modified emulsification method. Five formulations of beads (F1-F5) with different drug: polymer ratios were prepared in which the amount of drug (1g) was kept constant and the amount of calcium alginate was increased from 1 up to 5g. All the formulated beads were evaluated for percentage yield, entrapped efficiency and in vitro release profile at pH 1.2 and 7.2 dissolution media. For further minimize the release of drug from calcium alginate beads, the selected formulation F3 beads were coated separately with 3% and 6% Eudragit S100 solution using dipping method. The coated beads (F6 and F7) minimized the release of drug both in pH 1.2 and 7.2. The study confirms significant effects of two variables, drug:polymer ratio and coating on the release of drug from beads which can be effectively utilized to control the release from prepared calcium alginate formulations.

scholarly journals Simulation of Enzyme Catalysis in Calcium Alginate Beads

2012 ◽  
Vol 2012 ◽  
pp. 1-13 ◽  
Author(s):  
Ameel M. R. Al-Mayah
Keyword(s):  
Flow Rate ◽  
Calcium Alginate ◽  
Corn Starch ◽  
Fixed Bed ◽  
Average Diameter ◽  
Alginate Beads ◽  
Starch Hydrolysis ◽  
Steady State Condition ◽  
Hydrogel Beads ◽  
Constant Ph

A general mathematical model for a fixed bed immobilized enzyme reactor was developed to simulate the process of diffusion and reaction inside the biocatalyst particle. The modeling and simulation of starch hydrolysis using immobilized α-amylase were used as a model for this study. Corn starch hydrolysis was carried out at a constant pH of 5.5 and temperature of . The substrate flow rate was ranging from 0.2 to 5.0 mL/min, substrate initial concentrations 1 to 100 g/L. α-amylase was immobilized on to calcium alginate hydrogel beads of 2 mm average diameter. In this work Michaelis-Menten kinetics have been considered. The effect of substrate flow rate (i.e., residence time) and initial concentration on intraparticle diffusion have been taken into consideration. The performance of the system is found to be affected by the substrate flow rate and initial concentrations. The reaction is controlled by the reaction rate. The model equation was a nonlinear second order differential equation simulated based on the experimental data for steady state condition. The simulation was achieved numerically using FINITE ELEMENTS in MATLAB software package. The simulated results give satisfactory results for substrate and product concentration profiles within the biocatalyst bead.

Fabrication of monodisperse alginate microgel beads by microfluidic picoinjection: A chelate free approach

Lab on a Chip ◽  
2021 ◽  
Author(s):  
Husnain Ahmed ◽  
Bjørn Torger Stokke
Keyword(s):  
Calcium Alginate ◽  
Biomedical Applications ◽  
Alginate Beads ◽  
Alginate Hydrogel ◽  
Hydrogel Beads ◽  
Ca Alginate

Micron-sized alginate hydrogel beads are extensively employed as an encapsulation medium for biochemical and biomedical applications. Here we report on the microfluidic assisted fabrication of calcium alginate (Ca-alginate) beads by...

Characterization and in vitro digestibility of potato starch encapsulated in calcium alginate beads

2021 ◽  
pp. 107458
Author(s):  
Congli Cui ◽  
Han Jiang ◽  
Minghang Guan ◽  
Na Ji ◽  
Liu Xiong ◽  
...  
Keyword(s):  
Calcium Alginate ◽  
Potato Starch ◽  
Alginate Beads ◽  
In Vitro Digestibility ◽  
Calcium Alginate Beads

Preparation of Alginate/Poly(L-Arginine)-Chitosan Ternary Complex Microcapsules

2009 ◽  
Vol 3 ◽  
pp. 25-35 ◽  
Author(s):  
A.Z. Chen ◽  
Shi Bin Wang ◽  
L.J. Weng ◽  
M.Y. Chen
Keyword(s):  
Drug Release ◽  
Calcium Alginate ◽  
Ternary Complex ◽  
Alginate Beads ◽  
Optimum Operating ◽  
Response Property ◽  
Calcium Alginate Beads ◽  
First Order Kinetics ◽  
Stimuli Response

Following a polyelectrolytical complex reaction, alginate/poly(L-Arginine)-chitosan ternary complex microcapsules were prepared by coating poly(L-Arginine) and chitosan as membrane materials on calcium alginate beads, which were produced by a high-voltage electrostatic droplet generator. The influences on the diameter and uniformity of the calcium alginate beads were studied, and the optimum operating parameters were selected to produce microcapsules. The in vitro drug release behavior and pH stimuli-response of alginate/poly(L-Arginine)-chitosan ternary complex microcapsules were investigated. In comparison with alginate/chitosan microcapsules, alginate/poly(L-Arginine) microcapsules and their corresponding double-membrane microcapsules, alginate/poly(L-Arginine)-chitosan microcapsules released the macromolecular drug in a more sustained and stable way. It was found that they released 85.7% of the bovine erythrocytes hemoglobin (Hb) in 85 hours by approximate first-order kinetics in pH 6.8 PBS. While in a pH 1.0 HCl solution, only 9.6 % of the Hb was released in the first half hour and then the drug release shifted to a flat stage, which indicated that the alginate/poly(L-Arginine)-chitosan microcapsules possessed a pH stimuli-response property. The results suggest that the alginate/poly(L-Arginine)-chitosan ternary complex microcapsules might be a potential colon-targeted drug delivery system for the encapsulation of proteins.

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