title: Sodium dodecyl sulfate/β-cyclodextrin vesicles embedded in chitosan gel for insulin delivery with pH-selective release.
abstract: In an answer to the challenge of enzymatic instability and low oral bioavailability of proteins/peptides, a new type of drug-delivery vesicle has been developed. The preparation, based on sodium dodecyl sulfate (SDS) and β-cyclodextrin (β-CD) embedded in chitosan gel, was used to successfully deliver the model drug-insulin. The self-assembled SDS/β-CD vesicles were prepared and characterized by particle size, zeta potential, appearance, microscopic morphology and entrapment efficiency. In addition, both the interaction of insulin with vesicles and the stability of insulin loaded in vesicles in the presence of pepsin were investigated. The vesicles were crosslinked into thermo-sensitive chitosan/β-glycerol phosphate solution for an in-situ gel to enhance the dilution stability. The in vitro release characteristics of insulin from gels in media at different pH values were investigated. The insulin loaded vesicles-chitosan hydrogel (IVG) improved the dilution stability of the vesicles and provided pH-selective sustained release compared with insulin solution-chitosan hydrogel (ISG). In vitro, IVG exhibited slow release in acidic solution and relatively quick release in neutral solutions to provide drug efficacy. In simulated digestive fluid, IVG showed better sustained release and insulin protection properties compared with ISG. Thus IVG might improve the stability of insulin during its transport in vivo and contribute to the bioavailability and therapeutic effect of insulin.
authors.affiliation: School of Pharmacy, Shenyang Pharmaceutical University, Shenyang 110016, China; Center for Drug Delivery System, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China.
authors.forename: Zhuo
authors.initials: Z
authors.lastname: Li
authors.affiliation: Center for Drug Delivery System, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China.
authors.forename: Haiyan
authors.initials: H
authors.lastname: Li
authors.affiliation: Center for Drug Delivery System, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China.
authors.forename: Caifen
authors.initials: C
authors.lastname: Wang
authors.affiliation: Center for Drug Delivery System, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China; School of Pharmaceutical Sciences, Anhui University of Chinese Medicine, Hefei 230038, China.
authors.forename: Jianghui
authors.initials: J
authors.lastname: Xu
authors.affiliation: Center for Drug Delivery System, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China.
authors.forename: Vikramjeet
authors.initials: V
authors.lastname: Singh
authors.affiliation: School of Pharmacy, Shenyang Pharmaceutical University, Shenyang 110016, China.
authors.forename: Dawei
authors.initials: D
authors.lastname: Chen
authors.affiliation: School of Pharmacy, Shenyang Pharmaceutical University, Shenyang 110016, China; Center for Drug Delivery System, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, China.
authors.forename: Jiwen
authors.initials: J
authors.lastname: Zhang
keywords: Gel; Insulin; Self-assembly; Vesicles; pH-selective release; β-Cyclodextrin