What is US5637767 (Google Patents), and how does it relate to pregabalin?
US5637767 is a published patent record for an invention involving compounds tied to pregabalin chemistry, where mandelic acid is used as a counterion/forming agent. In practice, mandelic acid is often referenced in patents about forming “salts” of active drugs to improve properties such as crystallinity, stability, or drug formulation handling. The patent record is available through Google Patents for searching and citation purposes [1].
If you’re looking specifically for “pregabalin mandelic acid,” the relevant Google Patents entries are typically the ones describing:
- the pregabalin–mandelic acid salt composition, and/or
- processes for making that salt, and/or
- solid-state/crystal forms and formulation suitability.
Why do patents mention “mandelic acid” with pregabalin?
Drug-salt patents frequently focus on pharmaceutical salts rather than new active ingredients. Mandelic acid can be used to create a specific pregabalin salt that may have different physical characteristics than pregabalin alone, which can affect things like:
- solid-state form and reproducibility,
- solubility/dissolution behavior,
- shelf-life and stability,
- manufacturability (crystal formation and filtration handling).
That kind of salt-focused protection is common in the patent landscape around older small-molecule drugs like pregabalin [1].
How can you find the exact “pregabalin mandelic acid” claims on Google Patents?
On Google Patents, the quickest way is to search within the patent for:
- “mandelic acid”
- “pregabalin”
- “salt” / “acid addition salt”
- “crystalline” / “crystal form” / “polymorph”
In the US5637767 record itself, the “claims” section is usually the best place to confirm whether it protects:
- the salt as a composition of matter, or
- a method of preparing it, or
- a use in a formulation.
Does US5637767 look like an active-drug patent or a salt/crystal-form patent?
For searches like “pregabalin mandelic acid patent,” US-series records often target formulation-relevant inventions (salt and/or solid-state forms) rather than inventing pregabalin itself, which was discovered earlier. So US5637767 is most plausibly read as covering a specific pregabalin salt (mandelic acid) and/or ways to make it [1].
Is US5637767 still enforceable, or when does it expire?
US patent enforceability and expiration depend on the application filing date, patent term adjustments, and whether it’s been granted fully as a utility patent. To determine the exact status for US5637767, you’d check the “Status” and “Expiration” fields on the Google Patents page [1].
What to search next if you need the broader “pregabalin mandelic acid” patent family
If you’re doing a patent landscape search (not just one patent), you’ll usually want to expand beyond US5637767 to related members in the same family, which may appear as:
- continuation/divisional applications,
- corresponding filings in other jurisdictions,
- updated crystal form or process claims.
On Google Patents, using “Also published as” and “Similar documents” can help surface those related records [1].
Sources
[1] https://patents.google.com/patent/US5637767