You can freely build on The Discovery of Lovastatin for Lowering Cholesterol
This patent expired in 1999. Every claim — 0 independent, 0 dependent — is now unenforceable. Anyone can use, reproduce, manufacture, sell, or offer for sale this technology without a license.
Original assignee
Merck and Co Inc
Patent granted
1980
Expired
1999
Forward citations
490
What this patent covers
The patent details the isolation of a specific compound, initially designated MSD803, produced by fermenting the fungus Aspergillus. This compound, later known as lovastatin, functions as a potent inhibitor of cholesterol synthesis in the human body. The claims specifically protect the chemical structure of this lactone compound and its corresponding hydroxy acid form, which are used to treat high cholesterol and lipid levels.
What is now free to use
All 0 claims of US 4231938 are in the public domain. Specifically:
The 0 dependent claims add narrowing limitations and are also free.
What is NOT covered
Patent expiry frees this specific invention. Separately-patented improvements made after expiry may still be protected.
Does not cover synthetic statins developed later that share different chemical backbones.
Does not cover the general process of fermentation for non-cholesterol-lowering compounds.
Does not cover the use of the compound for treating conditions unrelated to cholesterol or lipid metabolism.
Who is building on this today
Merck & Co. pioneered this space, but the success of this patent led to a massive wave of research by companies like Pfizer, AstraZeneca, and Bristol-Myers Squibb, who developed subsequent generations of statins like atorvastatin and rosuvastatin.
Products built on expired version of this technology
Mevacor
Generic lovastatin medications
How to cite this patent in your documentation
Merck and Co Inc. US Patent 4231938. Hypocholesteremic fermentation products and process of preparation. Granted 1980, expired 1999. Now in the public domain.
Note: This is a convenience citation. Consult a patent attorney for formal freedom-to-operate analysis.
PatentBrief is an educational resource and does not provide legal advice. Patent expiration information is derived from USPTO records and may not reflect continuation patents, divisional filings, or separately-patented improvements. For commercial use or production decisions, obtain a formal freedom-to-operate (FTO) opinion from a registered patent attorney.