Novel Approaches for Oral Insulin Delivery - Pharmaceutical Technology

Latest Issue
PharmTech

Latest Issue
PharmTech Europe

Novel Approaches for Oral Insulin Delivery
The authors review various oral drug delivery systems that have been explored to increase patient compliance for insulin.


Pharmaceutical Technology
Volume 33, Issue 7

Liposomes

Insulin-entrapped liposomes cause dose-dependent hypoglycemia. Choudhari et al. prepared liposomes with varying composition by two methods: solvent evaporation hydration and solvent spherule evaporation (28). Liposomes containing lecithin 100 mg, cholesterol 20 mg, insulin 150 units, and Tween 1% v/v were found to be most effective. The effect of insulin-liposome was prolonged in diabetes-induced rabbits than that of normal rabbits. The pharmacodynamics of the insulin-liposome system was comparable with the action of 1 U/kg of insulin administered subcutaneously.

Coated liposomes. In another study, insulin liposomes were prepared by reversed phase separation and coated with chitosan of various molecular weights and concentrations (29). Chitosan coating was carried out by incubation of the liposomal suspensions with the chitosan solution. These chitosan-coated liposomes were administered to mice perorally and their hypoglycemic efficacy was determined. The insulin liposomes coated by 0.2% chitosan (MW 1000 kDa) showed maximum hypoglycemic efficacy. The minimum blood-glucose level and the hypoglycemic effect lasted for 4 h. Chitosan-coated liposomes also reduced tryptic digestion on insulin and enhanced enteral absorption of insulin. The molecular weights and concentrations of chitosan had significant effect on hypoglycemic efficacy of chitosan-coated insulin liposomes after oral administration to healthy mice.

In another study, insulin was bound covalently to the outer surface of multilamellar liposomes loaded with spin label (30). Electron spin resonance controlled encapsulation of the label tempocholine-nitroxide within the aqueous phases of liposomes. The binding of insulin was performed using the Carlsson's heterobifunctional reagent: N-succinimidyl 3-(2-pyridyldithio) propionate. The coupling method resulted in efficient attachment of 2.64.10(-4) mole of insulin per mole of phospholipid. Liposome coupled insulin retained its antigenic specificity as proved by radio immune assay.

DepoFoam (Pacira Pharmaceuticals, Parsippany, NJ) technology consists of novel multivesicular liposomes characterized by their unique structure of multiple nonconcentric aqueous chambers surrounded by a network of lipid membranes. Ye et al. demonstrated that DepoFoam technology can be used to develop sustained-release formulations of insulin with high loading (31). The data showed these formulations had a number of advantages, including high drug loading, high encapsulation efficiency, low content of free drug in the suspension, little chemical change in the drug caused by the formulation process, narrow particle-size distribution, and spherical particle morphology.


ADVERTISEMENT

blog comments powered by Disqus
LCGC E-mail Newsletters

Subscribe: Click to learn more about the newsletter
| Weekly
| Monthly
|Monthly
| Weekly

Survey
What role should the US government play in the current Ebola outbreak?
Finance development of drugs to treat/prevent disease.
Oversee medical treatment of patients in the US.
Provide treatment for patients globally.
All of the above.
No government involvement in patient treatment or drug development.
Finance development of drugs to treat/prevent disease.
30%
Oversee medical treatment of patients in the US.
9%
Provide treatment for patients globally.
8%
All of the above.
45%
No government involvement in patient treatment or drug development.
8%
Jim Miller Outsourcing Outlook Jim MillerCMO Industry Thins Out
Cynthia Challener, PhD Ingredients Insider Cynthia ChallenerFluorination Remains Key Challenge in API Synthesis
Marilyn E. Morris Guest EditorialMarilyn E. MorrisBolstering Graduate Education and Research Programs
Jill Wechsler Regulatory Watch Jill Wechsler Biopharma Manufacturers Respond to Ebola Crisis
Sean Milmo European Regulatory WatchSean MilmoHarmonizing Marketing Approval of Generic Drugs in Europe
Legislators Urge Added Incentives for Ebola Drug Development
FDA Reorganization to Promote Drug Quality
FDA Readies Quality Metrics Measures
New FDA Team to Spur Modern Drug Manufacturing
From Generics to Supergenerics
Source: Pharmaceutical Technology,
Click here