Biotechnology firm Apollo claims to have achieved mission impossible in the oral delivery of insulin by successfully lowering blood glucose levels in diabetic rats using its proprietary oral delivery technology.
Results from a series of preclinical studies indicate that oral feeding of diabetic rats with insulin using Apollo's Oradel platform resulted in reduction in blood glucose levels in responder animals of up to 80 per cent, which persisted for longer than six hours.
The Australian company is feeling triumphant because the stomach's digestive acids usually destroy insulin before it can be absorbed by the body, making oral insulin delivery norotiously difficult.
Most oral delivery technologies for therapeutic large water-soluble proteins, such as insulin, have therefore failed to overcome two major obstacles to effective oral delivery; the degradation of the protein by the harsh stomach environment and the poor absorption of the protein through the gut wall into the bloodstream.
As a result, diabetes patients can require up to 1,500 insulin injections a year, so any needle-free delivery route is welcomed with excitement, particularly if it is administered orally.
Apart from allowing the uptake of proteins from the gut into the bloodstream in an active form through the use of small molecule transporters and protecting the proteins from stomach enzymes, Apollo's technology also has the advantage of using unmodified insulin with a protective coating, which is less costly than the more recently developed long-acting injectable insulins.
"These studies provide evidence for Oradel's ability to protect insulin in the stomach environment and deliver it systemically at levels that lower glucose in the blood," said Apollo's science director Greg Russell-Jones.
"We are now preparing for clinical trial of oral insulin."
Apollo will conduct a human Phase 1b study in volunteers with diabetes through the International Diabetes Institute.
Pre-clinical studies indicate that Oradel can transport large protein molecules, up to 130kDa in weight in lattices of around 200nm in size.
The technology entraps insulin within a nanolattice to protect it in the stomach and uses targeting agents to promote absorption of insulin from the intestine.
Each cell in the stomach wall transports the nanolattice at a different rate, allowing for a controlled release of the drug into the circulation.
Once the nanolattice is released into circulation, the structure collapses and the drug is released.
Apollo says it has filed provisional patents on the new oral delivery formulation following promising in vitro results and pre-clinical experiments with a range of proteins up to antibody size and antibodies.
The company intends to use its own proteins produced from human cells to develop treatments for diseases ranging from rheumatoid arthritis and hepatitis C to multiple sclerosis and cancer.