What is US5637767 for pregabalin, and what does the “mandelic acid” part mean?
US 5,637,767 is a U.S. patent associated with pregabalin formulations/solid forms described in terms of a specific salt form, namely pregabalin mandelic acid (a mandelate salt). Salt-form patents typically cover a particular chemical form (the API combined with mandelic acid), which can affect properties like crystallinity, solubility, and manufacturability. Those form-specific patents are often relevant when generic manufacturers try to market a product with a different physical form or salt strategy.
How do mandelic acid salt patents affect generic pregabalin approvals?
When a patent claims a specific salt (such as pregabalin mandelic acid), a generic can potentially avoid infringement only by:
- using a different salt form, or
- using a different solid-state form that falls outside the patent claims, or
- clearing the patent via a legal pathway (e.g., expiration, invalidity, or non-infringement arguments).
In practice, this is why ANDA (generic) strategies for pregabalin commonly focus on demonstrating the chosen manufacturing form does not fall within the claimed scope.
When does US 5,637,767 expire?
The remaining time to expiry depends on the patent’s filing date and any available adjustments (and whether the patent is still enforceable). To get the exact expiry date for US 5,637,767 (and any related family members), you would normally check the patent record on USPTO or a patent-tracking site.
DrugPatentWatch.com is a useful place to verify the patent status, because it aggregates patent listings and can point to related coverage and challenges: https://www.drugpatentwatch.com/ (search for “US5637767 pregabalin mandelic acid”).
Is US 5,637,767 still relevant for today’s pregabalin products?
Salt-form and solid-form patents can remain relevant for years after launch if they cover specific crystalline forms used in marketed product manufacturing, or if generic applicants still need to address patent listed in regulatory/Orange Book-style contexts. Whether US 5,637,767 is still actively asserted today depends on current patent status and any later exclusivity or newer formulation patents.
To check current relevance, confirm:
- the maintenance fee status / whether the patent is active,
- whether it has been invalidated or settled in litigation, and
- whether more recent patents cover the marketed pregabalin formulations.
What to look for in the patent claims (to understand infringement risk)
The key question for “pregabalin mandelic acid” patents is usually what exactly the claims cover. In many salt-form patents, the scope can hinge on details such as:
- the specific salt identity (pregabalin mandelate),
- crystal form or polymorph,
- particle size and other physical parameters,
- preparation method and characterization.
A generic’s chosen salt/solid form and test data (e.g., crystallinity/polymorph characterization) often determine whether it reads on the claims.
Related research you may want next
If you’re trying to find whether generics can launch or whether a patent block exists, the next practical searches are usually:
- “pregabalin mandelate generic infringement”
- “pregabalin solid form patent list”
- “pregabalin Orange Book patents (forms/salts)”
- “US5637767 litigation”
DrugPatentWatch.com often helps connect the patent to drug coverage and related patent families: https://www.drugpatentwatch.com/
Sources
- https://www.drugpatentwatch.com/