title: Development of pH-sensitive insulin nanoparticles using Eudragit L100-55 and chitosan with different molecular weights.
abstract: Insulin is a polypeptide hormone and usually administered for treatment of diabetic patients subcutaneously. The aim of this study was to investigate the efficiency of enteric nanoparticles for oral delivery of insulin. Nanoparticles were formed by complex coacervation method using chitosan of various molecular weights. Nanoparticles were characterized by drug loading efficiency determination, particle size analysis, Scanning Electron Microscopy (SEM), Zeta potential and CD spectroscopy (Circular Dichrosim). The in vitro release studies were performed at pH 1.2 and 7.4. The drug loaded nanoparticles showed 3.38% of entrapment, loading efficiency of 30.56% and mean particle size of 199 nm. SEM studies showed that the nanoparticles are non-spherical. Zeta potential increased with increasing molecular weight of chitosan. The CD spectroscopy profiles indicated that the nano-encapsulation process did not significantly disrupt the internal structure of insulin; additionally, pH-sensitivity of nanoparticles was preserved and the insulin release was pH-dependent. These results suggest that the complex coacervation process using chitosan and Eudragit L100-55 polymers may provide a useful approach for entrapment of hydrophilic polypeptides without affecting their conformation.
authors.affiliation: Department of Pharmaceutics, Faculty of Pharmacy, Tabriz University of Medical Sciences, Tabriz, Iran.
authors.forename: Mitra
authors.initials: M
authors.lastname: Jelvehgari
authors.forename: Parvin
authors.initials: P
authors.lastname: Zakeri-Milani
authors.forename: Mohammad Reza
authors.initials: MR
authors.lastname: Siahi-Shadbad
authors.forename: Badir Delf
authors.initials: BD
authors.lastname: Loveymi
authors.forename: Ali
authors.initials: A
authors.lastname: Nokhodchi
authors.forename: Zahra
authors.initials: Z
authors.lastname: Azari
authors.forename: Hadi
authors.initials: H
authors.lastname: Valizadeh
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry*; D048271:Chitosan / Q000737:chemistry*; D003692:Delayed-Action Preparations / Q000138:chemical synthesis*; D004058:Diffusion; D006863:Hydrogen-Ion Concentration; D007328:Insulin / Q000008:administration & dosage / Q000737:chemistry*; D008970:Molecular Weight; D053758:Nanoparticles / Q000008:administration & dosage / Q000737:chemistry*
chemical_list: D000180:Acrylic Resins; D003692:Delayed-Action Preparations; C446821:Eudragit L100-55; D007328:Insulin; D048271:Chitosan