Molecular weight and degree of deacetylation effects on lipase-loaded chitosan bead characteristics

Alsarra, Ibrahim A.; Betigeri, Seema S; Zhang, Hua; Evans, Barry A.; Neau, Steven H.

doi:10.1016/s0142-9612(02)00096-0

Cited by 74 publications

(41 citation statements)

References 13 publications

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“…Drug-loaded hydrogel beads were produced by a modified literature technique [24,25] using TPP as the gelling counterion. Different amounts of 50% aqueous glutraldehyde solution were added.…”

Section: Preparation Of Vp Loaded Beadsmentioning

confidence: 99%

Chitosan Beads as a New Gastroretentive System of Verapamil

2006

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The main objective of this project is to design a new extended release gastroretentive mutiparticulate delivery system for verapamil (VP) by incorporation into hydrogel beads made of chitosan. The beads were formed by dropping solutions of VP and chitosan in a solution of tripolyphosphate using a syringe pump with adjustable constant rate. The formed beads were then further crosslinked using glutraldehyde and the excess glutraldehyde were then washed. The physical properties of the prepared beads such as beads sizes, shapes, friabilities and loading efficiencies were determined. The floating characteristics and the release profiles were also studied. The produced beads from all batches showed a very good spherical geometry with mean diameter in the range of 1.3 -2.0 mm. The drug loading efficiency was around 42% for all batches. The % friabilities were less than 1% indicating that the beads surfaces are highly resistant to attrition. Batches B 3 and B 4 (prepared using medium molecular weight chitosan) showed both the slowest release rate among all the prepared batches and showed good floating characteristics comprising short onset (around 5 minutes) and the long duration of buoyancy (more than 6 hours). All the batches exhibited a kinetic model of combined mechanism of diffusion partially through a swollen matrix and partially through water-filled pores. The preparation of chitosan beads using this technique would provide a simple and commercially viable method of preparation of chitosan beads for controlling the release of some drugs.

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Section: Preparation Of Vp Loaded Beadsmentioning

confidence: 99%

Chitosan Beads as a New Gastroretentive System of Verapamil

2006

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“…To date, there are only a few kinds of suitable systems well developed, such as Ca 2þ -crosslinked alginate [4][5][6][7][8] and tripolyphosphatecrosslinked chitosan. 9 For the applications as carriers of macromolecules, the entrapment efficiency is a key parameter. To reduce macromolecules loss from gel beads, several approaches have been achieved, including forming a chitosan coating at the bead surface, 4,5 adjusting the pH value of polymer solution slightly below the isoelectric point of loaded enzyme, 6 using a higher degree of deacetylation and a higher molecular weight (MW) of polymer matrix, 9 and adding a certain amount of bentonite to hold back the water in the beads.…”

Section: Introductionmentioning

confidence: 99%

“…9 For the applications as carriers of macromolecules, the entrapment efficiency is a key parameter. To reduce macromolecules loss from gel beads, several approaches have been achieved, including forming a chitosan coating at the bead surface, 4,5 adjusting the pH value of polymer solution slightly below the isoelectric point of loaded enzyme, 6 using a higher degree of deacetylation and a higher molecular weight (MW) of polymer matrix, 9 and adding a certain amount of bentonite to hold back the water in the beads. 6 Carboxymethyl chitosan (CMC), an important water-soluble derivative of chitosan, has many outstanding properties including nontoxicity, biodegradability, biocompatibility, antibacterial, and antifungal bioactivity.…”

Section: Introductionmentioning

confidence: 99%

Calcium‐carboxymethyl chitosan hydrogel beads for protein drug delivery system

Liu

Jiao

Zhang

2006

J of Applied Polymer Sci

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In this study, carboxymethyl chitosan (CMC) hydrogel beads were prepared by crosslinking with Ca 2þ . The pH-sensitive characteristics of the beads were investigated by simulating gastrointestinal pH conditions. As a potential protein drug delivery system, the beads were loaded with a model protein (bovine serum albumin, BSA). To improve the entrapment efficiency of BSA, the beads were further coated with a chitosan/CMC polyelectrolyte complex (PEC) membrane by extruding a CMC/BSA solution into a CaCl 2 /chitosan gelation medium. Finally, the release studies of BSA-loaded beads were conducted. We found that, the maximum swelling ratios of the beads at pH 7.4 (17-21) were much higher than those at pH 1.2 (2-2.5). Higher entrapment efficiency (73.2%) was achieved in the chitosan-coated calcium-CMC beads, compared with that (44.4%) in the bare calcium-CMC beads. The PEC membrane limited the BSA release, while the final disintegration of beads at pH 7.4 still leaded to a full BSA release. Therefore, the chitosan-coated calcium-CMC hydrogel beads with higher entrapment efficiency and proper protein release properties were a promising protein drug carrier for the site-specific release in the intestine.

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“…Characterization of chitosan: 4.1-Molecular weight of chitosan: Molecular weight of chitosan were measured and presented in Figure (3), the representative graph of the reduced viscosity (ηsp/c) in relation to the five solution concentrations used for the determination of intrinsic viscosity of the chitosan for shrimps shell. By using the equation of Alsarra et al (2002).…”

Section: -Isolation and Identification Of The Causal Organismsmentioning

confidence: 99%

Role of Chitosan Extracted from Shrimp Waste in Controlling Tomato Blackmold Disease Caused by Alternaria alternata

Zian

2016

Journal of Applied Plant Protection

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Tomato suffers from several diseases at all stages of its life. Blackmold, caused by Alternaria alternate (Fr.) Keissler is one of the most important postharvest disease of tomato. The effect of various concentrations of chitosan solution on A. alternata the causal agent of blackmold disease of tomato fruits on mycelial growth was studied. The isolate was tested in vitro using PDA amended with seven concentrations of chitosan (0, 1, 2, 3, 4, 5 and 6 mg ml -). Chitosan significantly (P < 0.05) inhibited the radial mycelial growth of this fungus by 67.4% at 6 mg ml 1 concentration. Tomato fruits treated with aqueous solution of chitosan compared with the Ipromise ® fungicide (Thiophonate-methyl 20% + Iprodione 20%) was artificially inoculated with A. alternata and incubated at 8, 18 and 28°C. Lesion diameters and total phenolic contents were recorded 7 and 14-days after inoculation. Chitosan also, significantly (P < 0.05) reduced the lesion diameters of tomato fruits which were smaller for all treatments when stored at 8°C compared to the control treatment. Chitosan treatment resulted in the highest increase in total phenolic contents over the untreated control. Whereas a less increase in total phenolic contents was recognized in fungicide treatment. In all treatments, total phenolic contents increased first and declined at the end of storage. The results of this study indicate that chitosan was a alternative safe coating method especially when stored at low temperature degree for prevents tomato fruits blackmold disease which causes economic losses during transportation, marketing and storage.

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Molecular weight and degree of deacetylation effects on lipase-loaded chitosan bead characteristics

Cited by 74 publications

References 13 publications

Chitosan Beads as a New Gastroretentive System of Verapamil

Chitosan Beads as a New Gastroretentive System of Verapamil

Calcium‐carboxymethyl chitosan hydrogel beads for protein drug delivery system

Role of Chitosan Extracted from Shrimp Waste in Controlling Tomato Blackmold Disease Caused by Alternaria alternata

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