Modified Microparticles of Calcium Alginate Gel for Controlled Release of Anesthetics

2007 ◽  
Vol 1060 ◽  
Author(s):  
Erkesh E. Batyrbekov ◽  
Turar N. Akylbekova ◽  
Rinat M. Iskakov

ABSTRACTThe aim of this work is the development of controlled delivery system immobilized by local anesthetics on the basis of modified microparticles of calcium alginate gels. The kazkain, rikhlokain, lidokain and novokain were used as local anesthetics. Modified microparticles were obtained by syringed dropwise a solution of ansthetics in sodium alginate into solution of polymers such as chitosan or polyethyleneimine in calcium chloride. The obtained modified alginate microparticles were contained immobilized anesthetics in core of particles and a surface layer of polymer. Effects of polymer concentration and exposure duration on the thickness of polymer coating were determined. The release of anesthetics from the modified alginate gel particles into a physiological solution with different thickness of coating were studied. All the release data show the typical pattern for a matrix controlled mechanism. The cumulative amount of drug released from alginate gels was linearly related to the square root of the time and the release rate decreased this time. The process is controlled by the diffusion of anesthetics through the polymeric coating. The data shown a possibility of the regulation of the rate of anesthetics release from the modified alginate particles by way of alternation of thickness of the polymer coating. The anesthetic effect of the alginate microparticles containing drugs was tested on rats by method “tail flick” according two criteria: full analgesia – the absence of reaction on pain and sufficient analgesia – exceeding of pain threshold sensibility two and more times. Medical-biological tests show that the duration of anesthetic activity for the drug-containing alginate beads increases at 5-8 times in comparison of free drugs.

1987 ◽  
Vol 19 (1-2) ◽  
pp. 175-182 ◽  
Author(s):  
Z. Lewandowski ◽  
R. Bakke ◽  
W. G. Characklis

Immobilization of nitrifiers and autotrophic denitrifiers (Thiobacillus denitrificans) within calcium alginate gel was demonstrated. Calcium carbonate reagent was immobilized along with bacteria as the stabilizing agent. Protons released as a result of microbial respiration reacted with calcium carbonate producing calcium ions which internally stabilized the calcium alginate gel. The microbially active gel beads were mechanically stable and active for three months in a continuous flow system without addition of calcium.


2011 ◽  
Vol 2 (2) ◽  
pp. 129-138 ◽  
Author(s):  
Q. Zhao ◽  
S. Lee ◽  
A. Mutukumira ◽  
I. Maddox ◽  
Q. Shu

The objective of the study was to design and produce calcium alginate beads that can deliver immobilised Lactobacillus reuteri DPC16 to a target site of the colon in the gastrointestinal (GI) tract. In this study, several factors that might affect the effectiveness of calcium alginate gel beads entrapping L. reuteri DPC16 cells were investigated. An in vitro GI tract model was used to simulate the pH variation and the existence of enzymes. Firstly, by varying the concentration of alginate at a constant concentration of CaCl2 the survival of immobilised DPC16 cells in simulated gastric fluid (SGF) was observed; secondly, the physical stability of calcium alginate beads containing skim milk during sequential incubation in the GI fluids was observed using optimal concentrations of alginate; finally, the survival of DPC16 cells immobilised within alginate beads containing skim milk were compared when the beads were incubated for different times during sequential exposure to the simulated fluids. The results demonstrated that non-encapsulated DPC16 cells were sensitive to an acidic environment, and no viable cells were detected after 90 min exposure in SGF (pH 1.2). With the protection of calcium alginate gel, the survival rate of immobilised DPC16 cells was slightly improved. An alginate concentration of 4% (w/v) was the most effective of those tested, but due to the irregular shape it formed, an alginate concentration of 3% (w/v) was used in further investigations. When skim milk (8% (w/v)) was added to the alginate solution, the cell survival was improved markedly. The optimal concentration of calcium chloride was 0.3 M, because the beads maintained their integrity in SGF and simulated intestinal fluid while disintegrating in simulated colonic fluid. The beads made from 3% alginate, 8% skim milk and 0.3 M CaCl2 proved to be an effective delivery and release system for DPC16 cells.


2010 ◽  
Vol 46 (4) ◽  
pp. 785-793 ◽  
Author(s):  
Sanchita Mandal ◽  
S. Senthil Kumar ◽  
Balakrishnam Krishnamoorthy ◽  
Sanat Kumar Basu

The objective of this study was to develop a sustained release dosage form of Trimetazidine dihydrochloride (TMZ) using a natural polymeric carrier prepared in a completely aqueous environment. TMZ was entrapped in calcium alginate beads prepared with sodium alginate by the ionotropic gelation method using calcium chloride as a crosslinking agent. The drug was incorporated either into preformed calcium alginate gel beads (sequential method) or incorporated simultaneously during the gelation stage (simultaneous method). The beads were evaluated for particle size and surface morphology using optical microscopy and SEM, respectively. Beads produced by the sequential method had higher drug entrapment. Drug entrapment in the sequential method was higher with increased CaCl2 and polymer concentration but lower with increased drug concentration. In the simultaneous method, drug entrapment was higher when polymer and drug concentration were increased and also rose to a certain extent with increase in CaCl2 concentration, where further increase resulted in lower drug loading. FTIR studies revealed that there is no interaction between drug and CaCl2. XRD studies showed that the crystalline drug changed to an amorphous state after formulation. Release characteristics of the TMZ loaded calcium alginate beads were studied in enzyme-free simulated gastric and intestinal fluid.


2020 ◽  
Author(s):  
Ian Mallov ◽  
Fiona Jeeva ◽  
Chris Caputo

Food is often wasted due to real or perceived concerns about preservation and shelf life. Thus, precise, accurate and consumer-friendly methods of indicating whether food is safe for consumers are drawing great interest. The colorimetric sensing of biogenic amines released as food degrades is a potential way of determining the quality of the food. Herein, we report the use of genipin, a naturally occurring iridoid, as a dual colorimetric sensor for both oxygen and biogenic amines. Immobilization of genipin in edible calcium alginate beads demonstrates that it is a capable sensor for amine vapors and can be immobilized in a non-toxic, food-friendly matrix.


2021 ◽  
Author(s):  
Gabriela Ionita ◽  
Elena Irina Popescu ◽  
Ludmila Aricov ◽  
Sorin Mocanu ◽  
Iulia Matei ◽  
...  

Alginate gels have been explored in relevant domains for daily life such as pharmaceutics and environmental. The structural features of alginate allow functionalization which, in extension, can modify the gel...


2001 ◽  
Vol 36 (7) ◽  
pp. 601-606 ◽  
Author(s):  
A Blandino ◽  
M Macı́as ◽  
D Cantero

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Gulnur Arabaci ◽  
Ayse Usluoglu

Water pollution due to release of industrial wastewater has already become a serious problem in almost every industry using dyes to color its products. In this work, polyphenol oxidase enzyme from quince (Cydonia Oblonga) leaves immobilized on calcium alginate beads was used for the successful and effective decolorization of textile industrial effluent. Polyphenol oxidase (PPO) enzyme was extracted from quince (Cydonia Oblonga) leaves and immobilized on calcium alginate beads. The kinetic properties of free and immobilized PPO were determined. Quince leaf PPO enzyme stability was increased after immobilization. The immobilized and free enzymes were employed for the decolorization of textile dyes. The dye solutions were prepared in the concentration of 100 mg/L in distilled water and incubated with free and immobilized quince (Cydonia Oblonga) leaf PPO for one hour. The percent decolorization was calculated by taking untreated dye solution. Immobilized PPO was significantly more effective in decolorizing the dyes as compared to free enzyme. Our results showed that the immobilized quince leaf PPO enzyme could be efficiently used for the removal of synthetic dyes from industrial effluents.


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