title: Chitosan-alginate microparticles as a protein carrier.
abstract: The oral administration of peptidic drugs requires their protection from degradation in the gastric environment and the improvement of their absorption in the intestinal tract. For these requirements, a microsystem based on cross-linked alginate as the carrier of bovine serum albumin (BSA), used as a model protein, was proposed. A spray-drying technique was applied to BSA/sodium alginate solutions to obtain spherical particles having a mean diameter less than 10 microm. The microparticles were hardened using first a solution of calcium chloride and then a solution of chitosan (CS) to obtain stable microsystems. The cross-linking process was carried out at different CS concentrations and pH values of the cross-linking medium. The CS concentration affected the BSA loading in the microparticles prepared at a pH value less than the protein isoelectric point (pI). Moreover, the BSA loading at a pH value less than the pI was higher than that at a pH similar to the pI regardless of the CS concentration. This finding could be attributable to the formation of a BSA/alginate complex. The evaluation of the interaction between BSA and alginate at different pH values by means rheological measurements confirmed this hypothesis. This approach may represent a promising way to devise a microcarrier system with appropriate size for targeting the Peyer's patches, with appropriate immobilization capacity, and suitable for the oral administration of peptidic drugs.
authors.affiliation: Department of Pharmaceutical Sciences, University of Modena and Reggio Emilia, Modena, Italy. coppi.gilberto@unimo.it
authors.forename: G
authors.initials: G
authors.lastname: Coppi
authors.forename: V
authors.initials: V
authors.lastname: Iannuccelli
authors.forename: E
authors.initials: E
authors.lastname: Leo
authors.forename: M T
authors.initials: MT
authors.lastname: Bernabei
authors.forename: R
authors.initials: R
authors.lastname: Cameroni
mesh_terms: D000464:Alginates / Q000737:chemistry*; D000818:Animals; D001704:Biopolymers / Q000737:chemistry; D002122:Calcium Chloride / Q000737:chemistry; D002352:Carrier Proteins / Q000737:chemistry*; D002417:Cattle; D002686:Chitin / Q000031:analogs & derivatives / Q000737:chemistry*; D048271:Chitosan; D004339:Drug Compounding; D015195:Drug Design; D020723:Glucuronic Acid; D006603:Hexuronic Acids; D006863:Hydrogen-Ion Concentration; D012710:Serum Albumin, Bovine / Q000737:chemistry; D013329:Structure-Activity Relationship
chemical_list: D000464:Alginates; D001704:Biopolymers; D002352:Carrier Proteins; D006603:Hexuronic Acids; D002686:Chitin; D012710:Serum Albumin, Bovine; D020723:Glucuronic Acid; D048271:Chitosan; D002122:Calcium Chloride