skip to content
Dovepress - Open Access to Scientific and Medical Research
View our mobile site

8852

Liposomes containing glycocholate as potential oral insulin delivery systems: preparation, in vitro characterization, and improved protection against enzymatic degradation

Original Research

(1563) Views  (755) Full article downloads

Authors: Niu M, Lu Y, Hovgaard L, Wu W

Published Date June 2011 Volume 2011:6 Pages 1155 - 1166
DOI: http://dx.doi.org/10.2147/IJN.S19917

Mengmeng Niu1, Yi Lu1, Lars Hovgaard2, Wei Wu1
1School of Pharmacy, Fudan University, Shanghai, People's Republic of China; 2Oral Formulation Development, Novo Nordisk A/S, Maalov, Denmark

Background: Oral delivery of insulin is challenging and must overcome the barriers of gastric and enzymatic degradation as well as low permeation across the intestinal epithelium. The present study aimed to develop a liposomal delivery system containing glycocholate as an enzyme inhibitor and permeation enhancer for oral insulin delivery.
Methods: Liposomes containing sodium glycocholate were prepared by a reversed-phase evaporation method followed by homogenization. The particle size and entrapment efficiency of recombinant human insulin (rhINS)-loaded sodium glycocholate liposomes can be easily adjusted by tuning the homogenization parameters, phospholipid:sodium glycocholate ratio, insulin:phospholipid ratio, water:ether volume ratio, interior water phase pH, and the hydration buffer pH.
Results: The optimal formulation showed an insulin entrapment efficiency of 30% ± 2% and a particle size of 154 ± 18 nm. A conformational study by circular dichroism spectroscopy and a bioactivity study confirmed the preserved integrity of rhINS against preparative stress. Transmission electron micrographs revealed a nearly spherical and deformed structure with discernable lamella for sodium glycocholate liposomes. Sodium glycocholate liposomes showed better protection of insulin against enzymatic degradation by pepsin, trypsin, and a-chymotrypsin than liposomes containing the bile salt counterparts of sodium taurocholate and sodium deoxycholate.
Conclusion: Sodium glycocholate liposomes showed promising in vitro characteristics and have the potential to be able to deliver insulin orally.

Keywords: liposomes, glycocholate, insulin, enzymatic degradation, oral




 

Other articles by Professor Wei Wu



Readers of this article also read:

Radiolucency below the crown of mandibular horizontal incompletely impacted third molars and acute inflammation in men with diabetes
Berberine: metabolic and cardiovascular effects in preclinical and clinical trials
Potential renovascular hypertension, space missions, and the role of magnesium
Critical appraisal of the role of glucosamine and chondroitin in the management of osteoarthritis of the knee
Ego mechanisms of defense are associated with patients’ preference of treatment modality independent of psychological distress in end-stage renal disease
Can a gentamicin-specific chart reduce neonatal medication errors?
Nephroprotective action of glycosaminoglycans: why the pharmacological properties of sulodexide might be reconsidered
Dashboards in neonatology
Everolimus-eluting stents: update on current clinical studies
Metabolic pathway and distribution of superparamagnetic iron oxide nanoparticles: in vivo study