The Chemical Formula for Atorvastatin, the Active Ingredient in Lipitor
This patent describes the chemical structure of a class of molecules designed to block the enzyme responsible for cholesterol production in the human body.
Original patent title: “Trans-6-[2-(3- or 4-carboxamido-substituted pyrrol-1-yl)alkyl]-4-hydroxypyran-2-one inhibitors of cholesterol synthesis”
This patent describes the chemical structure of a class of molecules designed to block the enzyme responsible for cholesterol production in the human body. Granted to Warner Lambert Co LLC in 1987 with 10 claims and 340 forward citations.
Coverage
What does this patent actually cover?
The patent claimsclaimsThe numbered statements at the end of a patent that legally define what the inventor owns.Read more → a specific chemical structure—a pyrrole-based compound—that acts as an inhibitor of the enzyme HMG-CoA reductase. By blocking this enzyme, the compound prevents the liver from synthesizing cholesterol. The structure includes a lactone ring, which can open into a hydroxy acid form that is biologically active in the body. ClaimclaimA numbered sentence at the end of a patent that legally defines what the inventor owns. The most important section.Read more → 5 specifically identifies the chemical structure that would later become known as Atorvastatin.
The gap
What does this patent NOT cover?
- Does not cover naturally occurring cholesterol-lowering compounds found in plants or fungi.
- Does not cover other classes of cholesterol-lowering drugs like fibrates or bile acid sequestrants.
- Does not cover the specific manufacturing process or industrial synthesis route for the compound.
- Does not cover the use of these compounds for treating conditions unrelated to cholesterol biosynthesis.
These exclusions are unique to PatentBrief — derived from the actual claim language, not patent-office boilerplate.
Key facts
What made this novel
The inventorinventorThe person who actually conceived the invention. Listed on the patent regardless of who owns it.Read more → successfully utilized a pyrrole core to create a potent, synthetic inhibitor that mimics the transition state of the HMG-CoA reductase reaction, effectively tricking the enzyme into shutting down.
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
Lipitor (Atorvastatin)
Why it matters
The bigger picture
This patent is the foundation for Atorvastatin, marketed as Lipitor. It became one of the most commercially successful pharmaceutical products in history, fundamentally changing how doctors treat high cholesterol and cardiovascular disease.
Filed
May 30, 1986
Granted
July 21, 1987
Market context
Who's building on this
Companies in this space
Warner-Lambert, which was later acquired by Pfizer, developed this discovery into a global blockbuster. Today, generic pharmaceutical manufacturers produce versions of this molecule globally now that the original patent protection has expired.
Market impact
This patent enabled the creation of the statin drug class, which became the standard of care for managing hypercholesterolemia. It generated billions in revenue for Pfizer and significantly reduced cardiovascular mortality rates globally.
Claim 1 — Plain English
What this patent covers
The patent claims a specific chemical structure—a pyrrole-based compound—that acts as an inhibitor of the enzyme HMG-CoA reductase. By blocking this enzyme, the compound prevents the liver from synthesizing cholesterol. The structure includes a lactone ring, which can open into a hydroxy acid form that is biologically active in the body. Claim 5 specifically identifies the chemical structure that would later become known as Atorvastatin.
The clever bit
The inventor successfully utilized a pyrrole core to create a potent, synthetic inhibitor that mimics the transition state of the HMG-CoA reductase reaction, effectively tricking the enzyme into shutting down.
What it does not cover
- Does not cover naturally occurring cholesterol-lowering compounds found in plants or fungi.
- Does not cover other classes of cholesterol-lowering drugs like fibrates or bile acid sequestrants.
- Does not cover the specific manufacturing process or industrial synthesis route for the compound.
- Does not cover the use of these compounds for treating conditions unrelated to cholesterol biosynthesis.
Patent timeline
Application submitted to the patent office
Application published, typically 18 months after filing
Patent officially issued
PatentBrief Score
Impact Score
Moderate
Citation count
40/40
Highly cited
Claim breadth
7/20
Moderate scope
Recency
0/20
Older than 20 years
Assignee scale
0/20
Independent or smaller assigneeassigneeThe entity that owns the patent — usually the inventor's employer or a company.Read more →
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
$135K – $432K
Midpoint $270K · 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.
Patent Claims
1 independent claim · 0 dependent
Claims are the legal boundaries of the patent. An independent claim stands alone. A dependent claim adds limitations to its parent, narrowing — but not broadening — the scope.
The original legal language
Original claims
10 claims as filed with the patent office.
Concepts involved
Citations
Patent lineage
Cite this patent
Roth, B. D. (1987). The Chemical Formula for Atorvastatin, the Active Ingredient in Lipitor (U.S. Patent No. 4,681,893). U.S. Patent and Trademark Office. https://patentbrief.org/patent/us/4681893/prozac-fluoxetine
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 The Chemical Formula for Atorvastatin, the Active Ingredient in Lipitor cover?
This patent describes the chemical structure of a class of molecules designed to block the enzyme responsible for cholesterol production in the human body.
Who owns patent US 4681893?
Warner Lambert Co LLC owns this patent, granted in 1987.
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 4681893 cited by?
This patent has been cited by 340 later patents that build on its ideas.
What problem does this patent solve?
This patent is the foundation for Atorvastatin, marketed as Lipitor. It became one of the most commercially successful pharmaceutical products in history, fundamentally changing how doctors treat high cholesterol and cardiovascular disease.
What does this patent NOT cover?
Does not cover naturally occurring cholesterol-lowering compounds found in plants or fungi.
Same assignee
More from Warner Lambert Co LLC
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