title: Release of amoxicillin from polyionic complexes of chitosan and poly(acrylic acid). Study of polymer/polymer and polymer/drug interactions within the network structure.
abstract: Polyionic complexes of chitosan (CS) and poly(acrylic acid) (PAA) were prepared in a wide range of copolymer composition and with two kind of drugs. Release of amoxicillin trihydrate and amoxicillin sodium from these different complexes were studied. The swelling behavior of and solute transport in swellable hydrogels were investigated to check the effect of polymer/polymer and polymer/drugs interactions. The electrostatic polymer/polymer interactions take place between the cationic groups from CS and the anionic ones from PAA. The diffusion of amoxicillin trihydrate was controlled only by the swelling/eroding ratio of the polyionic complexes. The swelling degree of amoxicillin sodium hydrogels was more extensive when compared to the swelling degree of amoxicillin trihydrate formulations. It was concluded that the water uptake was mainly governed by the degree of ionization. Restriction of amoxicillin sodium diffusion could be achieved by polymer/ionized-drug interaction that retards the drug release. Freeze-dried polyionic complexes could serve as suitable candidates for amoxicillin site-specific delivery in the stomach.
authors.affiliation: Department of Pharmaceutical Technology, School of Pharmacy, Complutense University, Avda Complutense S/N, Madrid 28040, Spain.
authors.forename: Paloma M
authors.initials: PM
authors.lastname: de la Torre
authors.forename: Yewande
authors.initials: Y
authors.lastname: Enobakhare
authors.forename: Guillermo
authors.initials: G
authors.lastname: Torrado
authors.forename: Susana
authors.initials: S
authors.lastname: Torrado
mesh_terms: D000180:Acrylic Resins; D000658:Amoxicillin / Q000008:administration & dosage* / Q000493:pharmacokinetics*; D001672:Biocompatible Materials; D002686:Chitin / Q000031:analogs & derivatives*; D048271:Chitosan; D003692:Delayed-Action Preparations; D016503:Drug Delivery Systems; D005756:Gastritis / Q000188:drug therapy; D016481:Helicobacter Infections / Q000188:drug therapy; D016480:Helicobacter pylori; D006801:Humans; D020100:Hydrogels; D066298:In Vitro Techniques; D007477:Ions; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D010406:Penicillins / Q000008:administration & dosage* / Q000493:pharmacokinetics*; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D000180:Acrylic Resins; D001672:Biocompatible Materials; D003692:Delayed-Action Preparations; D020100:Hydrogels; D007477:Ions; D010406:Penicillins; C065246:chitosan-poly(acrylic acid); D002686:Chitin; D000658:Amoxicillin; D048271:Chitosan