Using Vitamin B12 to Help Proteins Survive the Human Digestive System
A method for attaching therapeutic proteins to Vitamin B12 so they can be absorbed through the gut instead of being injected.
Patent Number
US 5574018
Status
Active
Filing Date
July 29, 1994
Grant Date
November 12, 1996
Expiration
~July 2014 (estimated)
Claims
27
Assignee
Amgen Inc
Inventors
Alan D. Habberfield, Colin G. Pitt, Olaf B. Kinstler
Citations
46 forward · 9 backward
What it covers
This patent describes a chemical trick to help large, fragile therapeutic proteins survive the harsh environment of the human stomach and intestines. By covalently linking a protein—like erythropoietin or interferon—to the primary hydroxyl site of a Vitamin B12 molecule, the drug hitches a ride on the body's natural B12 absorption pathway. The patent claims specific chemical formulas for these conjugates and a method for synthesizing them using dicarboxylic acid derivatives. When taken orally, the B12 acts as a transport vehicle, potentially allowing patients to take pills instead of receiving painful injections.
What it doesn't cover
- —Does not cover the use of Vitamin B12 as a standalone nutritional supplement.
- —Does not cover non-covalent mixtures or simple physical blends of protein and B12.
- —Does not cover conjugation methods that attach to parts of the B12 molecule other than the primary 5'-hydroxyl group on the ribose moiety.
- —Does not cover protein delivery systems that rely on liposomes or nanoparticle encapsulation.
The clever bit
The innovation lies in hijacking the body's highly specific, evolutionarily conserved transport mechanism for Vitamin B12 to smuggle large, complex therapeutic proteins across the intestinal wall.
Why it matters
Many life-saving drugs, particularly those made by recombinant DNA technology, are proteins that the stomach acid would destroy before they could reach the bloodstream. This patent represents an early attempt to solve the 'oral delivery' problem for biologics, which remains a massive hurdle in pharmaceutical engineering. If successful, such technology could replace daily injections for patients with chronic conditions like anemia or immune deficiencies.
Real-world examples
- 1.Oral delivery systems for recombinant proteins like erythropoietin (EPO).
- 2.Oral formulations of granulocyte colony-stimulating factor (G-CSF).
- 3.Experimental oral interferon therapies.
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US 5574018 · 2026