title: Cross-linked high amylose starch derivatives as matrices for controlled release of high drug loadings.
abstract: Selection of hydrogels as excipients in controlled drug release systems depends on the characteristics of the gel and of the drug. Three types of derivatives were synthesized from cross-linked high amylose starch (HASCL-6) by substitution of hydroxylic groups with cationic (carboxymethyl: CM), anionic (aminoethyl: AE) and acetate (Ac) groups. These new polymeric excipients are able to control the release over 20 h from monolithic tablets loaded with 20 to 60% drug. Three drugs were used as model tracer: acetaminophen (uncharged), acetylsalicylic acid (having an acidic group) and metformin (having a basic group). It was found that the release of ionic drugs from CM-HASCL-6 and AE-HASCL-6 matrices can be partially controlled by ionic interaction between pendant groups of polymer and drugs. The substitution degree of HASCL-6 derivatives can also be varied to modulate the drug's release time. These derivatives represent a novel generation of pharmaceutical excipients, recommended for high loading dosage formulations.
authors.affiliation: Department of Chemistry and Biochemistry, Université du Québec à Montréal, C.P. 8888, Succ. A, Québec H3C 3P8, Montréal, Canada.
authors.forename: J
authors.initials: J
authors.lastname: Mulhbacher
authors.forename: P
authors.initials: P
authors.lastname: Ispas-Szabo
authors.forename: V
authors.initials: V
authors.lastname: Lenaerts
authors.forename: M A
authors.initials: MA
authors.lastname: Mateescu
mesh_terms: D000082:Acetaminophen / Q000008:administration & dosage / Q000737:chemistry; D000688:Amylose; D016503:Drug Delivery Systems; D005079:Excipients / Q000008:administration & dosage*; D012995:Solubility; D013213:Starch / Q000008:administration & dosage*
chemical_list: D005079:Excipients; D000082:Acetaminophen; D013213:Starch; D000688:Amylose