## Facts

- An inventor obtained an invention patent for a composition to prevent and treat calcium deficiency; Claim 1 specified a composition made from active calcium, zinc gluconate, and glutamine or glutamic acid in stated weight ranges.
- During examination, the applicant narrowed the claim term from “soluble calcium agent” (covering multiple calcium salts) to “active calcium” after an examiner required amendment due to lack of support for the broader scope.
- The patentee granted an exclusive license to a pharmaceutical company, authorizing it to enforce the patent against infringers.
- The licensee purchased, under notarization, an oral solution product manufactured by another pharmaceutical company and sold by a retail pharmacy.
- The accused product’s labeled/registered ingredients were calcium gluconate, zinc gluconate, and lysine hydrochloride.
- A court-appointed technical appraisal concluded the accused product was equivalent to the claimed invention, reasoning that calcium gluconate was interchangeable with active calcium and lysine hydrochloride was equivalent to glutamine/glutamic acid for promoting calcium absorption.
- The trial court found infringement, enjoined production/sales, awarded damages and fees against the manufacturer, and ordered the retailer to stop selling the product; the appellate court affirmed.
- The Supreme People’s Court granted retrial and reviewed claim construction, equivalence, and the effect of claim narrowing during prosecution.

## Issues

1. How should Claim 1 be construed, including whether it is a closed composition claim and how “active calcium” should be interpreted in context?
2. Is calcium gluconate identical or equivalent to “active calcium” under the doctrine of equivalents?
3. Is lysine hydrochloride identical or equivalent to “glutamine or glutamic acid” under the doctrine of equivalents?
4. Can technical solutions surrendered during patent prosecution be recaptured through equivalence in an infringement action?

## Decision

- The Supreme People’s Court reversed the lower-court judgments and dismissed all infringement claims.
- The Court held the accused product did not fall within Claim 1 because calcium gluconate and lysine hydrochloride were neither identical nor equivalent to the claimed components.
- The Court treated Claim 1 as a closed composition claim listing an exhaustive set of components.
- The Court applied a prosecution-history estoppel/no-recapture rule barring equivalence for subject matter abandoned by amendment or argument during patent examination, regardless of whether the abandonment related to novelty or inventiveness.
- Costs, including the technical appraisal fee, were ultimately borne by the plaintiff/licensee.

## Legal Principles

- Claim terms must be construed in context; courts may determine the meaning of technical terms by reference to the specification’s technical content and other claims.
- For a closed composition claim, infringement turns on whether the accused product contains the claimed components (or legally permissible equivalents) as specified, rather than functionally similar substitutes.
- The doctrine of equivalents does not extend to technical solutions the patentee surrendered during prosecution through amendments or arguments; such surrendered scope cannot be recaptured in litigation.
- Equivalence requires interchangeability in the relevant technical context and substantially similar technical means and effects; generalized functional similarity is insufficient where material technical differences exist.

## Conclusion

The Supreme People’s Court found no infringement because the accused oral solution used calcium gluconate and lysine hydrochloride, which were not equivalent to the patented claim’s “active calcium” and “glutamine or glutamic acid,” and it held that prosecution-stage narrowing foreclosed any attempt to reclaim surrendered scope via the doctrine of equivalents.


Hubei Wushi Pharms. Grp. Co. v. Aonuo (China) Pharms. Co. & Wang Junshe, (2009) Min Ti Zi No. 20 (Sup. People’s Ct. 2010)