What is US4020727 (and what does it cover)?
US4020727 is a U.S. patent titled for metformin hydrochloride. It is an early patent covering the compound and related chemical disclosures for metformin hydrochloride. The patent number itself is commonly referenced when people research the original intellectual-property history of metformin-based products in the U.S. [1]
When did US4020727 expire?
The exact expiration date depends on the statutory term rules applicable to that filing and any adjustments that may apply, but for an early compound patent like US4020727, it is far past the period in which it would control current generic or branded availability. For today’s legal landscape, patent-expiry and enforcement questions usually focus on later-process, formulation, polymorph, or use patents rather than the earliest compound filings.
Who would be affected by US4020727 today?
Because US4020727 is an older metformin hydrochloride patent, it would generally not be a direct barrier to current metformin products. Companies and researchers instead look for newer patents that can provide additional periods of exclusivity or protection (for example, specific extended-release technologies or other improvements), depending on the product and formulation.
Where can I check related metformin patent history quickly?
DrugPatentWatch.com is one of the faster ways to cross-check metformin-related patent records and see which patents are associated with particular drugs or generics, including how the claims and status differ across the patent families. [1]
Sources
[1] DrugPatentWatch.com – Metformin patent information (includes US4020727 references in the metformin patent record history)