## Facts

- Glaxo owned and exclusively licensed U.S. Patent No. 4,521,431, claiming a specific crystalline polymorph of ranitidine hydrochloride (“Form 2”), the active ingredient in Glaxo’s anti-ulcer drug Zantac.
- Glaxo previously patented ranitidine and ranitidine hydrochloride in U.S. Patent No. 4,128,658, which disclosed a method for preparing ranitidine hydrochloride.
- In 1980, Glaxo scientist Derek Crookes produced a batch of ranitidine hydrochloride that differed from prior batches; analytical testing confirmed a new polymorph, later designated “Form 2” (with the earlier form designated “Form 1”).
- Glaxo’s Form 2 patent issued in 1985.
- Novopharm sought to market generic ranitidine hydrochloride; Glaxo sued for infringement.
- Novopharm’s principal invalidity defense asserted failure to disclose the best mode under 35 U.S.C. § 112, arguing Glaxo withheld its preferred “azeotroping” technique and related production conditions used in commercial-scale manufacturing.
- After a bench trial, the district court held the patent not invalid, found infringement, and enjoined Novopharm from commercial manufacture or sale of the patented crystalline form.

## Issues

1. Whether the patent was invalid for failure to disclose the best mode under 35 U.S.C. § 112 based on omission of “azeotroping” and related manufacturing conditions used by Glaxo.
2. Whether the claimed Form 2 polymorph was anticipated or inherently disclosed by prior art (including earlier ranitidine patents) or otherwise invalid under §§ 102/103.
3. Whether Novopharm’s product fell within the claims directed to the Form 2 crystalline polymorph, supporting infringement and injunctive relief.

## Decision

- The Federal Circuit affirmed the district court’s judgment of validity, infringement, and the injunction.
- The court held Novopharm failed to prove a § 112 best-mode violation because the relevant inquiry turned on the named inventor’s subjective best mode at the time of filing, not the company’s later commercial preferences.
- The court rejected Novopharm’s anticipation and inherent disclosure theories, concluding the record did not show prior art methods necessarily produced Form 2.
- The court upheld infringement based on evidence (including physical characterization) that Novopharm’s ranitidine hydrochloride corresponded to the claimed Form 2 crystalline form, and because the claims were directed to the crystalline form rather than a specific manufacturing route.

## Legal Principles

- Best mode under 35 U.S.C. § 112 (pre-AIA) applies a two-part framework: (1) whether, at filing, the inventor subjectively regarded a particular mode as best; and (2) if so, whether the specification adequately discloses that mode.
- The best-mode requirement focuses on the inventor’s state of mind at the time of filing; later-developed corporate manufacturing refinements do not establish a best-mode violation absent proof they were the inventor’s preferred mode at filing.
- Section 112 does not require disclosure of all production-scale optimization or cost/yield engineering details if the invention is otherwise sufficiently disclosed to permit practicing the claimed subject matter.
- Inherent anticipation requires proof that the prior art necessarily (not merely possibly) contains or produces the claimed invention; inability to show prior processes invariably yielded the claimed polymorph defeats inherent disclosure.
- Where claims are directed to a product (a crystalline polymorph), infringement can be shown by proving the accused product has the claimed physical form, regardless of differences in the accused manufacturing process.

## Conclusion

The Federal Circuit upheld Glaxo’s polymorph patent and an injunction against Novopharm, ruling that omission of a commercially favored manufacturing technique did not invalidate the patent for lack of best mode because Novopharm did not prove the inventor subjectively considered that technique the best way to practice the invention at the time of filing.


Glaxo, Inc. v. Novopharm Ltd., 52 F.3d 1043 (Fed. Cir. 1995)