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.
Original patent title: “Conjugates of vitamin B12 and proteins”
A method for attaching therapeutic proteins to Vitamin B12 so they can be absorbed through the gut instead of being injected. Granted to Amgen Inc in 1996 with 27 claims and 46 forward citations.
Key facts
Coverage
What does this patent actually cover?
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 claimsclaimsThe numbered statements at the end of a patent that legally define what the inventor owns.Read more → 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.
The gap
What does this patent NOT 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.
These exclusions are unique to PatentBrief — derived from the actual claim language, not patent-office boilerplate.
What made this novel
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.
Schematic visualization of the patent's claim structure. Hand-drawn diagrams in progress for each landmark patent.
Where you've seen this
Real-world examples
Oral delivery systems for recombinant proteins like erythropoietin (EPO).
Oral formulations of granulocyte colony-stimulating factor (G-CSF).
Experimental oral interferon therapies.
Why it matters
The bigger picture
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.
Filed
July 29, 1994
Granted
November 12, 1996
Market context
Who's building on this
Companies in this space
Amgen, the original assigneeassigneeThe entity that owns the patent — usually the inventor's employer or a company.Read more →, has long been a leader in protein therapeutics. The broader field of oral biologic delivery is currently being explored by companies like Oramed Pharmaceuticals and various startups focusing on enteric-coated delivery or chemical modification of proteins to resist enzymatic degradation.
Market impact
This patent addressed a fundamental limitation in the delivery of biologics, which were becoming the backbone of modern medicine in the 1990s. While oral delivery of complex proteins remains a difficult challenge, the strategy of using endogenous transport pathways like the B12 receptor continues to be a subject of intense research in drug delivery science.
Claim 1 — Plain English
What this patent 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.
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.
What it does not 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.
Patent timeline
Application submitted to the patent office
Application published, typically 18 months after filing
Patent officially issued
PatentBrief Score
Impact Score
Strong
Citation count
33/40
Moderately cited
Claim breadth
18/20
Very broad protection
Recency
0/20
Older than 20 years
Assignee scale
20/20
Major company or institution
PatentBrief Impact Score — based on citation count, claim breadth, recency, and assignee scale. Not a legal assessment.
Heuristic Value Estimate
What this patent might be worth
$53K – $168K
Midpoint $105K · expired or expiring · industry ×3.0
Heuristic only — blends forward/backward citation counts, claim scope, time remaining, litigation history, and CPC-derived industry baseline. Real valuations need a professional appraisal.
The original legal language
Original claims
27 claims as filed with the patent office.
Concepts involved
Citations
Patent lineage
Cite this patent
Habberfield, A. D., Pitt, C. G., & Kinstler, O. B. (1996). Using Vitamin B12 to Help Proteins Survive the Human Digestive System (U.S. Patent No. 5,574,018). U.S. Patent and Trademark Office. https://patentbrief.org/patent/us/5574018/herceptin-trastuzumab
Auto-generated from the patent record. Double-check author order and the issue date against the official USPTO document before submitting.
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Common Questions
Frequently Asked Questions
What does Using Vitamin B12 to Help Proteins Survive the Human Digestive System cover?
A method for attaching therapeutic proteins to Vitamin B12 so they can be absorbed through the gut instead of being injected.
Who owns patent US 5574018?
Amgen Inc owns this patent, granted in 1996.
When does this patent expire?
This patent has expired and is now in the public domain — anyone can use the invention freely.
What is patent US 5574018 cited by?
This patent has been cited by 46 later patents that build on its ideas.
What problem does this patent solve?
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.
What does this patent NOT cover?
Does not cover the use of Vitamin B12 as a standalone nutritional supplement.
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