scholarly journals MICROENCAPSULATION of grapefruit oil with sodium alginate by gelation and ionic extrusion: optimization and modeling of crosslinking and study of controlled release kinetics.

2020 ◽  
pp. 41-61
Author(s):  
Liliana Mariel Cáceres ◽  
Gustavo Adolfo Velasco ◽  
Eliana Paola Dagnino ◽  
Ester R Chamorro
Keyword(s):  
Controlled Release ◽  
Sodium Alginate ◽  
Calcium Chloride ◽  
Release Kinetics ◽  
Antimicrobial Properties ◽  
Chloride Concentration ◽  
Crosslinking Process ◽  
Elovich Equation ◽  
Pharmaceutical Industries ◽  
High Concentrations

Essential grapefruit oil with high concentrations of limonene is used in food, cosmetic and pharmaceutical industries due to its antimicrobial properties, fragrance, and flavor. To facilitate its manipulation and protect it from adverse environmental factors, the microencapsulation is used. The objective of this work was to optimize the microencapsulation process of grapefruit oil using external ionic gelation coupled to extrusion with sodium alginate and calcium chloride. We achieved the best encapsulation conditions with calcium chloride concentration at 7.4% w/v and a crosslinking time of 58 minutes, obtaining a yield of 62% and an efficiency of 100% with an oil loading capacity of 10% w/w. The chemical adsorption of calcium as well during the crosslinking process was studied, observing a significant fit with the Elovich equation. And an adjustment of the controlled release of the oil was obtained to the empirical kinetic model of Korsmeyer and Peppas.

scholarly journals DESIGN AND EVALUATION OF CONTROLLED-RELEASE OCULAR INSERTS OF BRIMONIDINE-TARTRATE AND TIMOLOL MALEATE

2016 ◽  
Vol 9 (1) ◽  
pp. 79 ◽  
Author(s):  
Preethi G. B. ◽  
Prashanth Kunal
Keyword(s):  
Controlled Release ◽  
Drug Release ◽  
Sodium Alginate ◽  
Calcium Chloride ◽  
Release Kinetics ◽  
Water Soluble ◽  
Moisture Loss ◽  
Timolol Maleate ◽  
Brimonidine Tartrate

<p><strong>Objective: </strong>The current work was attempted to formulate and evaluate a controlled-release matrix-type ocular inserts containing a combination of brimonidine tartrate and timolol maleate, with a view to sustain the drug release in the cul-de-sac of the eye.<strong></strong></p><p><strong>Methods: </strong>Initially, the infrared studies were done to determine the drug–polymer interactions. Sodium alginate-loaded ocuserts were prepared by solvent casting technique. Varying the concentrations of polymer—sodium alginate, plasticizer—glycerine, and cross-linking agent—calcium chloride by keeping the drug concentration constant, made a total of nine formulations. These formulations were evaluated for its appearance, drug content, weight uniformity, thickness uniformity, percentage moisture loss, percentage moisture absorption, and <em>in vitro </em>release profile of the ocuserts. Finally, accelerated stability studies and the release kinetics were performed on the optimised formulation.<strong></strong></p><p><strong>Results: </strong>It was perceived that polymer, plasticizer, and calcium chloride had a significant influence on the drug release. The data obtained from the formulations showed that formulation—F9 was the optimised formulation, which exhibited better drug release. The release data of the optimised formulation tested on the kinetic models revealed that it exhibited first-order release kinetics. <strong></strong></p><p><strong>Conclusion: </strong>It can be concluded that a natural bioadhesive hydrophilic polymer such as sodium alginate can be used as a film former to load water soluble and hydrophilic drugs like brimonidine tartrate and timolol maleate. Among all formulations, F9 with 400 mg sodium alginate, 2% calcium chloride and 60 mg glycerin were found to be the most suitable insert in terms of appearance, ease of handling, thickness, <em>in vitro</em> drug release and stability.</p>

scholarly journals Formulation and development of metformin-loaded microspheres using Khaya senegalensis (Meliaceae) gum as co-polymer

2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Chukwuebuka H. Ozoude ◽  
Chukwuemeka P. Azubuike ◽  
Modupe O. Ologunagba ◽  
Sejoro S. Tonuewa ◽  
Cecilia I. Igwilo
Keyword(s):  
Controlled Release ◽  
Sodium Alginate ◽  
Release Kinetics ◽  
Drug Carrier ◽  
In Vitro Release ◽  
Entrapment Efficiency ◽  
Metformin Hydrochloride ◽  
Scanning Calorimetry ◽  
Khaya Senegalensis

Abstract Background Khaya gum is a bark exudate from Khaya senegalensis (Maliaecae) that has drug carrier potential. This study aimed to formulate and comparatively evaluate metformin-loaded microspheres using blends of khaya gum and sodium alginate. Khaya gum was extracted and subjected to preformulation studies using established protocols while three formulations (FA; FB and FC) of metformin (1% w/v)-loaded microspheres were prepared by the ionic gelation method using 5% zinc chloride solution as the cross-linker. The formulations contained 2% w/v blends of khaya gum and sodium alginate in the ratios of 2:3, 9:11, and 1:1, respectively. The microspheres were evaluated by scanning electron microscopy, Fourier transform-infrared spectroscopy, differential scanning calorimetry, entrapment efficiency, swelling index, and in vitro release studies. Results Yield of 28.48%, pH of 4.00 ± 0.05, moisture content (14.59% ± 0.50), and fair flow properties (Carr’s index 23.68 ± 1.91 and Hausner’s ratio 1.31 ± 0.03) of the khaya gum were obtained. FTIR analyses showed no significant interaction between pure metformin hydrochloride with excipients. Discrete spherical microspheres with sizes ranging from 1200 to 1420 μm were obtained. Drug entrapment efficiency of the microspheres ranged from 65.6 to 81.5%. The release of the drug from microspheres was sustained for the 9 h of the study as the cumulative release was 62% (FA), 73% (FB), and 80% (FC). The release kinetics followed Korsmeyer-Peppas model with super case-II transport mechanism. Conclusion Blends of Khaya senegalensis gum and sodium alginate are promising polymer combination for the preparation of controlled-release formulations. The blend of the khaya gum and sodium alginate produced microspheres with controlled release properties. However, the formulation containing 2:3 ratio of khaya gum and sodium alginate respectively produced microspheres with comparable controlled release profiles to the commercial brand metformin tablet.

Evaluation of Alginate-Starch Polymers for Preparation of Enzyme Microcapsules

2006 ◽  
Vol 2 (2) ◽  
Author(s):  
Kasipathy Kailasapathy ◽  
Chaminda Perera ◽  
Michael Phillips
Keyword(s):  
Sodium Alginate ◽  
Calcium Chloride ◽  
Chloride Solution ◽  
Encapsulation Efficiency ◽  
Chloride Concentration ◽  
Calcium Chloride Solution ◽  
Filler Material ◽  
Enzyme Release ◽  
Alginate Solution

Flavourzyme® (a protease-peptidase complex) was microencapsulated with sodium alginate and Hi-MaizeTM starch in varying concentrations and proportions for maximising encapsulation efficiency (EE). Seventy two percent EE was achieved for immobilising Flavourzyme® using 1.8% (w/v) sodium alginate and 1% Hi-Maize[TM] starch with 30 min hardening of capsules in 0.1M calcium chloride solution. Hi-MaizeTM starch as a filler material improved EE and reduced the enzyme release during capsular hardening in calcium chloride solution. Increasing the concentration of sodium alginate solution (1.2 to 1.8 %, w/v) and calcium chloride concentration (0.05M to 1.0M) increased the EE. The optimum hardening time for the microcapsules in calcium chloride solution was 30 min. Shrinkage of microcapsules during hardening in calcium chloride was less with higher concentration of alginate. More spherical capsules were produced with up to 1.8% (w/v) sodium alginate and 1% Hi-MaizeTM starch solutions.

Effects of Process Variables on Size of Chitosan-Alginate Capsules through Extrusion-Dripping Method

2014 ◽  
Vol 925 ◽  
pp. 8-12 ◽  
Author(s):  
Gim Pao Lim ◽  
Hui Yen Ong ◽  
Boon Beng Lee ◽  
Muhammad Syarhabil Ahmad ◽  
Harbant Singh ◽  
...  
Keyword(s):  
Sodium Alginate ◽  
Calcium Chloride ◽  
Concentration Ratio ◽  
Inner Core ◽  
Gelation Time ◽  
Chloride Concentration ◽  
Membrane Thickness ◽  
Process Variables ◽  
Alginate Capsules ◽  
Alginate Concentration

The objective of this study was to investigate the effects of process variables on size of chitosan-alginate capsules produced through extrusion-dripping method. Chitosan-calcium chloride solution was extruded into sodium alginate to form chitosan-alginate capsules which have a defined inner core and membrane. The results showed that sodium alginate concentration, chitosan concentration, chitosan to calcium chloride concentration ratio, needle diameter, gelation time have significant effect on the diameter and membrane thickness of chitosan-alginate capsules. Under the tested condition, chitosan-alginate capsules with diameter in a range of 3.4 mm to 4.5 mm were produced. The membrane thickness of the capsules increased when the curing time increased from 5 min to 60 min. As the concentration of sodium alginate (0.3-0.9 %w/v) and chitosan (0.4-1.0 %w/v) increased, the diameter of the chitosan-alginate capsules increased. The diameter of chitosan-alginate capsules increased with decreasing the chitosan to calcium chloride concentration ratio (1:0.5-1:1.5).

scholarly journals Alginate-pomegranate peels' polyphenols beads: effects of formulation parameters on loading efficiency

2014 ◽  
Vol 50 (4) ◽  
pp. 741-748 ◽  
Author(s):  
Wissam Zam ◽  
Ghada Bashour ◽  
Wassim Abdelwahed ◽  
Warid Khayata
Keyword(s):  
Sodium Alginate ◽  
Calcium Chloride ◽  
Calcium Alginate ◽  
Chloride Concentration ◽  
Natural Antioxidants ◽  
Alginate Beads ◽  
Food Supplementation ◽  
Calcium Alginate Beads ◽  
Loading Efficiency ◽  
Alginate Concentration

Calcium alginate beads containing pomegranate peels' polyphenol extract were encapsulated by ionic gelation method. The effects of various formulation factors (sodium alginate concentration, calcium chloride concentration, calcium chloride exposure time, gelling bath time maintaining, and extract concentration) on the efficiency of extract loading were investigated. The formulation containing an extract of 1 g pomegranate peels in 100 mL distilled water encapsulated with 3 % of sodium alginate cured in 0.05 M calcium chloride for 20 minutes and kept in a gelling bath for 15 minutes was chosen as the best formula regarding the loading efficiency. These optimized conditions allowed the encapsulation of 43.90% of total extracted polyphenols and 46.34 % of total extracted proanthocyanidins. Microencapsulation of pomegranate peels' extract in calcium alginate beads is a promising technique for pharmaceutical and food supplementation with natural antioxidants.

scholarly journals Controlled Release of TBH Herbicide Encapsulated on Ca-ALG Microparticles: Leaching and Phytointoxication Plants

2019 ◽  
Vol 37 ◽  
Author(s):  
D.F. MACEDO ◽  
S.M. DOURADO JR. ◽  
E.S. NUNES ◽  
R.P. MARQUES ◽  
J.A. MORETO
Keyword(s):  
Aqueous Solution ◽  
Controlled Release ◽  
Soil Contamination ◽  
Sodium Alginate ◽  
Calcium Chloride ◽  
Calcium Alginate ◽  
Dry Mass ◽  
Leaching Process ◽  
The One

ABSTRACT: The aim of this work was to demonstrate a detailed study of the controlled release of the herbicide Tebuthiuron (TBH) encapsulated in microparticles of calcium alginate (Ca-ALG), to evaluate the phytotoxicity in different concentrations of herbicide (4, 6 and 8 g L-1), and their correlation with the depth of leaching using bioindicator plants. The Ca-ALG microparticles were prepared from the crosslinking of sodium alginate by Ca++ containing varied amounts of TBH supplied in calcium chloride (CaCl2) aqueous solution. The results showed that TBH herbicide, when encapsulated, leached to shallow depths relative to the conventional, non-encapsulated herbicide (which moved to a depth of 40-50 cm). The concentration of 4 g L-1 was the one that leached most in the PVC columns, but its mobility did not exceed 30 cm of depth. The results of the dry mass corroborated with the phytotoxicity results of the bioindicator plants, evidencing the mobility of the conventional herbicide in the soil at depths around 40 and 50 cm, while the herbicide encapsulated in the Ca-ALG microparticles did not show leaching beyond 20 -30 cm deep. The encapsulation of TBH in Ca-ALG microparticles can thus be considered as a more eco-friendly technology, reducing the leaching process and consequently soil contamination.

Understanding Release Kinetics of Calcium Alginate Microcapsules Using Drop on Demand Inkjet Printing

2009 ◽  
Author(s):  
Jessica L. Perkins ◽  
Salil Desai ◽  
Benjamin Harrison ◽  
Jagannathan Sankar
Keyword(s):  
Sodium Alginate ◽  
Calcium Chloride ◽  
Calcium Alginate ◽  
Rhodamine 6G ◽  
Release Kinetics ◽  
Release Behavior ◽  
On Demand ◽  
Drop On Demand ◽  
Kinetics Of ◽  
Rhodamine 6G Dye

This paper investigates the use of calcium alginate microcapsules to transport biomaterials for drug delivery. Rhodamine 6G dye was encapsulated in microcapsules for different formulations of the hydrogels using drop-on-demand printing. An experimental design was constructed to compare the effect of different concentrations of calcium chloride (M) and sodium alginate (% w/v) solutions in addition to the microcapsule diameter on the release kinetics profiles of the microcapsules. The results of these findings provide a basis to identify favorable sizes of microcapsules and concentrations of sodium alginate and calcium chloride solutions for controlled release behavior of microcapsules.

Evaluation of Aceclofenac Loaded Alginate Mucoadhesive Spheres Prepared by Ionic Gelation

2013 ◽  
Vol 5 (4) ◽  
pp. 1847-1857
Author(s):  
M. Mohan Varma ◽  
H.L.N Rao
Keyword(s):  
Controlled Release ◽  
Sodium Alginate ◽  
Calcium Chloride ◽  
Zero Order ◽  
Fickian Diffusion ◽  
Content Uniformity ◽  
Drug Content ◽  
Mucoadhesive Property ◽  
Drug Polymer Interaction ◽  
Polymer Interaction

Controlled release aceclofenac spheres were prepared in a cross-linked alginate matrix using ionotropic gelation technique. A suspension of aceclofenac in sodium alginate solution was added drop wise into 10% w/v calcium chloride solution and the resulting spheres were evaluated for their drug content, flow properties, mucoadhesive property and the dissolution rate. The aceclofenac loaded alginate spheres were prepared using various mucoadhesive polymers: sodium alginate, HPMC, sodium CMC, guar gum, methyl cellulose and carbopol. The calcium chloride was used as the crosslinking agent. Fourier transform infrared spectroscopy (FTIR) was used to evaluate the drug-polymer interaction. The alginate spheres showed good rheological properties, drug content uniformity and high entrapment efficiency. The aceclofenac release from the spheres was slow and extended up to 10 hours. The drug loaded spheres exhibited good mucoadhesive property in the in vitro wash off test. The drug release from the optimized formulation (drug-sodium alginate-HPMC K15M; 1:0.9: 0.1 ratio) followed zero order kinetics and exhibited non-Fickian diffusion. The rate of release of aceclofenac decreased with increasing concentration of sodium alginate due to slow penetration of dissolution fluid in the spheres. The results suggest that alginate spheres can potentially deliver aceclofenac at zero-order controlled release following oral administration. The FTIR studies indicated the absence of the drug-polymer interaction in the solid state.

scholarly journals Optimasi Pembuatan Mikrokapsul Kalsium-Alginat-EDTA Sebagai Adsorben Untuk Logam Kadmium

2020 ◽  
Vol 15 (4) ◽  
pp. 384
Author(s):  
Sani Widyastuti Pratiwi ◽  
Ayu Triastuti ◽  
Ratna Nurmalasari ◽  
Inggis Pinarti
Keyword(s):  
Sodium Alginate ◽  
Calcium Chloride ◽  
Functional Groups ◽  
Calcium Alginate ◽  
Chloride Concentration ◽  
Wave Number ◽  
Optimum Conditions ◽  
Retention Capacity ◽  
Alginate Concentration ◽  
Cadmium Metal

Cadmium was one of the metals classified in the type of nonessential heavy metal that classified as carcinogenic and is one of the pollutants in the environment, especially water. The content of cadmium in water tends to have very low levels, so certain techniques are needed to determine the level of pre concentration. In the pre concentration technique adsorbents were needed which could absorb cadmium, one of which is calcium-alginate microcapsule modified with EDTA. Calcium-alginate was  modified with EDTA to increase the ability of the microcapsule to absorb cadmium metal. The purpose of this study was to determine the optimum conditions for making Calcium-alginate-EDTA microcapsule in adsorbing cadmium. The stages of this research were optimization of Calcium-alginate-EDTA resin with variable in the form of Calcium chloride concentration (0.05 M; 0.1 M; 0.5 M; 1 M; and 2 M), EDTA mass (0.50 g ; 0.75 g; 1 g; 2 g and 2.5 g) and the concentration of sodium-alginate (0.5%; 1%, 1.5%; 2%, and 3%); Characterization of microcapsule functional groups by infrared spectrophotometry and determination of the retention capacity of Calcium-Alginate-EDTA microcapsule for cadmium absorption by atomic absorption spectrophotometry. The results of infrared characterization showed a change in transmittance in the functional groups C-O dan C-N that occurred in the microcapsule after binding to cadmium metal at wave number 1436.97 cm-1. The optimum conditions for making Calcium-alginate-EDTA resins were in conditions of 0.1 M Calcium chloride concentration, 1% sodium-alginate concentration and EDTA mass 0.75 g EDTA with retention capacity of  Cd was 0.0301 mg/g.

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