Chitosan/polyethylene glycol-alginate microcapsules for oral delivery of hirudin

Abstract

ABSTRACT:A mild chitosan/calcium alginate microencapsulation process, as applied to encapsulation of biological macromolecules such as albumin and hirudin, was investigated. The polysaccharide chitosan was reacted with sodium alginate in the presence of calcium chloride to form microcapsules with a polyelectrolyte complex membrane. Hirudin-entrapped alginate beads were further surface coated with polyethylene glycol (PEG) via glutaraldehyde functionalities. It was observed that approximately 70% of the content is being released into Tris-HCl buffer, pH 7.4 within the initial 6 h and about 35% release of hirudin was also observed during treatment with 0.1 M HCl, pH 1.2 for 4 h. But acid-treated capsules had released almost all the entrapped hirudin into Tris-HCl, pH 7.4 media within 6 h. From scanning electron microscopic and swelling studies, it appears that the chitosan and PEG have modified the alginate microcapsules and subsequently the protein release. The microcapsules were also prepared by adding dropwise albumin-containing sodium alginate mixture into a PEG-CaCl 2 system. Increasing the PEG concentration resulted in a decrease rate of albumin release. The results indicate the possibility of modifying the formulation to obtain the desired controlled release of bioactive peptides (hirudin), for a convenient gastrointestinal tract delivery system.

Dual drug-loaded nanoparticles on self-integrated scaffold for controlled delivery

“…Using a solvent casting method, the self-assembled biological scaffold film was prepared using various ratios of excipients, ie, sodium alginate, polyvinyl alcohol, hyaluronic acid, xylitol, and polyethylene glycol-600, in order to attain thermosensitive properties. 29 Furthermore, the excipients used showed key pharmaceutical properties, including biocompatibility, safety, 30 anti-infective properties, controlled release, 31,32 flexibility, emollient, adhesion, spreadability, and retention ability for film formulation. [33][34][35] The physicochemical properties, drug release, and cell compatibility characteristics of the scaffold film were studied.…”

Microencapsulation of hemoglobin in chitosan-coated alginate microspheres prepared by emulsification/internal gelation

“…The relatively mild cross-linking conditions required for obtaining chitosan-coated alginate microparticles and the nontoxicity and biodegradability of these 2 naturally occurring biopolymers have enabled them to be used for the encapsulation of a wide variety of biologically active agents including proteins, [3][4][5][6][7][8][9][10][11][12][13] enzymes, [14][15][16] antibodies, 17 cells, [18][19][20][21][22][23] and DNA. [24][25][26][27] Alginate is an anionic copolymer of 1,4-linked-b -Dmannuronic acid and a -L-guluronic acid residues.…”

Lactic Acid Production for Pharmaceutical Applications by Lactobacillus Delbrueckii Immobilized on Chitosan and Polyethylene Glycol Stabilized Calcium Alginate Beads: Process Optimization Using Response Surface Methodology

“…A chitosan/PEG-alginate microencapsulation process, [25] applied to biological macro-molecules such as albumin or hirudin, was reported to be a good candidate for oral delivery of bioactive peptides. [26] Laurienzoet al [27] reported protocol for the synthesis of new alginate-g-PEG copolymers that retain the gelation characteristics of alginate. values of Na-alginate and bead diameter show the optimum yield.…”