title: Preparation and characterization of controlled release matrices based on novel seaweed interpolyelectrolyte complexes.
abstract: Novel interpolyelectrolyte complexes (IPECs) between naturally sulfated polysaccharides of the seaweed Polysiphonia nigrescens (PN) and cationized agaroses (CAG) and Eudragit E (EE) were prepared using an organic solvent free process, characterized, and explored for controlled drug release. Tablets containing model drug ibuprofen and IPECs were prepared by direct compression. Drug release in acid medium was low owing to the low solubility of ibuprofen in that condition and to the matrix action. Zero order drug release was determined in the buffer stage (pH=6.8), with Fickian diffusion predominating over relaxation during the initial phases. Relaxation appears to increase along the release process and even overcomes diffusion for some systems. Drug release profiles could be controlled by varying the content of IPECs in the tablets. Also, the change in molecular weight and the degree of substitution of the components allowed altering the release profiles.
authors.affiliation: Departamento de Química Orgánica - CIHIDECAR-(CONICET-UBA), Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, C1428EGA Buenos Aires, Argentina.
authors.forename: Héctor J
authors.initials: HJ
authors.lastname: Prado
authors.forename: María C
authors.initials: MC
authors.lastname: Matulewicz
authors.forename: Pablo R
authors.initials: PR
authors.lastname: Bonelli
authors.forename: Ana L
authors.initials: AL
authors.lastname: Cukierman
mesh_terms: D003692:Delayed-Action Preparations; D004058:Diffusion; D004339:Drug Compounding / Q000379:methods; D004573:Electrolytes / Q000737:chemistry; D005079:Excipients / Q000737:chemistry*; D007052:Ibuprofen / Q000008:administration & dosage / Q000737:chemistry*; D008970:Molecular Weight; D011108:Polymers / Q000737:chemistry*; D011109:Polymethacrylic Acids / Q000737:chemistry; D011134:Polysaccharides / Q000737:chemistry; D012624:Seaweed / Q000737:chemistry*; D012685:Sepharose / Q000737:chemistry; D012995:Solubility; D013607:Tablets
chemical_list: D003692:Delayed-Action Preparations; D004573:Electrolytes; D005079:Excipients; D011108:Polymers; D011109:Polymethacrylic Acids; D011134:Polysaccharides; D013607:Tablets; D012685:Sepharose; C518398:Eudragit E PO; D007052:Ibuprofen