Chitosan complexed carboxymethylated iota-carrageenan oral insulin particles: Stability, permeability and in vivo evaluation
Document Type
Article
Publication Date
1-1-2019
Abstract
We previously reported that insulin-entrapped chitosan complexed carboxymethylated iota-carrageenan (CS/CMCi) particles exhibit pH-responsive swelling behavior. However, the particles’ stability in the enzymatic gastrointestinal environment, their drug permeability mechanism, and related in vivo studies have not been discussed to date. In this study, we investigated the stability, muco-adhesiveness, transport mechanism and in vivo assessment of the particles. The particles retained their bioactivity and displayed a generally stable behavior in the simulated enzymatic environment of the gastrointestinal tract with high muco-adhesiveness (79.1 ± 4.3%). The results of cellular membrane permeability experiments further suggested that insulin from the insulin-entrapped particles was transported across the Caco-2 cell monolayers mainly via the paracellular pathway. This activity was inferred by the trans-epithelial electrical resistance (TEER) and the apparent permeability coefficient (Papp) of the insulin-entrapped particles (22-fold greater than control insulin solution), suggesting that the opening of tight junctions (TJs) of Caco-2 cells was involved in the process. The particles did not exhibit significant cytotoxicity at 0.5–10.0 mg/mL based on 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salts (MTS) and lactate dehydrogenase (LDH) assays. Additionally, an in vivo study with diabetic Sprague Dawley (SD) rats revealed an extended blood glucose-lowering effect for up to 36 h (Cmax: 175.1 ± 23.7 mIU/L, Tmax: 5 h, AUC: 1789.4 ± 158.6). The estimated bioavailability of insulin from CS/CMCi particles in humans was 44.7–46.9%, which may be increased three fold compared with rats. Thus, the above results support the effectiveness of chitosan-complexed carboxymethylated iota-carrageenan particles as an oral insulin delivery system for extended glycemic control in basal insulin therapy. © 2019 Elsevier Ltd
Keywords
Diabetes mellitus, Insulin, Proteolytic, Cytotoxicity, Intestinal transport, Glycemia
Divisions
fac_med
Funders
Ministry of Higher Education, Malaysia, for the financial support throughout this project from the High Impact Research Grants (Grant No. UM.C/625/1/HIR/MOHE/MED/17 and UM.C/625/1/HIR/MOHE/MED/33)
Publication Title
Materials Today Communications
Volume
20
Publisher
Elsevier