Sanyou Client: Liyang Weixin Biotechnology Co., Ltd., etc.

Sanyou Attorneys: Xiaolin Dang/Dongcheng Pang/Liang Yao

Trial Organ: Supreme People’s Court

Trial Result: Maintain the original judgment and declare the other party’s related patent claims invalid

Case Facts

Lin Yuan, Ltd. (hereinafter referred to as "the patentee") is the right owner of patents No. ZL201280055581.8 and No. ZL201510463085.1, of which ZL201510463085.1 is the divisional application of ZL201280055581.8. Both patents involved require protection of a powder of α, α-trehalose dihydrate crystals (hereinafter referred to as "crystalline trehalose powder"), and defines the core parameters such as crystallinity of the crystalline trehalose powder. 

Trehalose is a known product in prior art and is widely used in the food industry, pharmaceutical industry and cosmetics. The patentee has defined the crystalline trehalose powder with physical parameters, claiming to be able to produce a powder with excellent low consolidation and good solubility.

Liyang Weixin Biotechnology Co., Ltd. and other companies intended to file invalidation requests against the patent involved. A professional team consisting of Xiaolin Dang (attorney-at-law), Dongcheng Pang (patent attorney) and Liang Yao (patent attorney) accepted the entrustment.

After full search and careful planning of strategies, Sanyou team filed invalidation requests against the two patents involved in the case in September 2018. In the invalidation request, Sanyou team deeply analyzed the physical meaning of the parameters defined in the claim and the relationship between the physical meaning and the technical effect.

On the relationship between crystallinity and solidity: in the patent concerned, the crystalline trehalose powder is defined by the user-defined physical parameter "crystallinity", which is different from the common definition of crystallinity. Its physical meaning is actually the proportion of crystalline trehalose dihydrate in the crystalline trehalose powder.

Sanyou team used textbooks as evidence to prove that moisture absorption can lead to powder consolidation. That is, as common knowledge in the art, the consolidation of powder is usually caused by its hygroscopicity. It can be seen that the higher the crystallinity of crystalline trehalose powder, the higher the content of non-hygroscopic crystalline trehalose dihydrate, the lower the content of hygroscopic amorphous trehalose, and the less easy for the crystalline trehalose powder to consolidate.

Therefore, those skilled in the art have known that there is a correlation between crystallinity and consolidation, and it is easy to conceive improving the consolidation of powder by adjusting crystallinity.

With regard to the relationship between crystallinity and solubility: Sanyou team fully discussed that the technical effect of using crystallinity to improve solubility claimed by the patentee could not be established by using the records in each part of the specification of the patent involved, especially in the patent involved, the crystalline trehalose powder did not actually have technical problems related to solubility.

With the above considered, Sanyou team believed that the patent involved was not inventive. CNPA supported Sanyou's grounds for invalidation and declared the related patent claims invalid.

The patentee filed administrative proceedings with the Beijing Intellectual Property Court and the Supreme People's Court in succession. After many years of trials, the Supreme People's Court made final judgments on January 29, 2023, (2021) Supreme Law Zhixing No. 887 and (2021) Supreme Law Zhixing No. 994, rejecting all claims of the patentee and maintaining the original ruling.

Typical Significance

By defining the parameters, a patentee is fully possible to include the known products in prior art into the scope of patent protection, thus impeding the public interest. However, product claims defined by parameters (especially user-defined parameters), due to the difficulty of proof, have been a hard nut to crack in invalidation litigations.

The Supreme People's Court held that for judging the inventiveness of known chemical products represented by parameters, it should generally consider whether the prior art has already covered the correlation between the parameters and the technical effects claimed in the specification. If the prior art has revealed the relevant parameters and the technical effects that can be brought about, or if a person skilled in the art can know how to obtain corresponding technical effects by adjusting the parameters based on common knowledge in the art; and if the technical means to adjust this parameter also belong to prior art that is easy to be combined; it would be obvious (rather than inventive) to use the known chemical products with defined parameters.

This case has important reference significance for the invalidation of product claims with defined parameters.