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Thailand – Patent on Traditional Knowledge (Pueraria Candollei) – Thai Supreme Court Decision No. 4783/2549

Pueraria Candollei (also known as Peuraria Mirifica), commonly known as Thai Kudzu, is an herb often found in various parts of Thailand. Thai people have long traditional knowledge on the use of this her. The Pueraria Candollei is mostly found in mixed forest where two or more dominant species grow. Researchers in various countries discovered that this herb is useful in medical and cosmetic applications. The inventions containing Pueraria Candollei were patented in many countries such as Thailand, Japan, and U.S.A. Pueraria Candollei is well known as Elixir for old-aged people. The demand is from those who believe that this herb can extend their lives and improve their health. It is also noted that teenagers should not consume it. As the Pueraria Candollei is well known as Elixir, there is a big market for this product targeting mature adults.

In Thailand, a product patent entitled “Herb Ingredient from Pueraria Candollei” was granted in 1999 as Patent No. 8912. After grant of the patent, the patentee advertised the patent in a newspaper and publicly informed other manufacturers to stop producing/selling the patented product. These manufacturers later filed a suit against the patentee and claimed that Patent No. 8912 is invalid as it lacks novelty and inventive step. Generally, there must be an allegation of infringement first before the alleged infringer can take action to revoke the patent. However, in this case, the Supreme Court allowed Plaintiffs, which are manufacturers of the product from Pueraria Candollei, to take an action to invalidate the patent even without infringement allegation.

During substantive examination before granting a patent, Patent Examiner must conduct prior art searches to ensure that the invention is novel and has inventive step. However, at the time of grant of the said patent, such traditional knowledge was not well-documented and available for search in a database. In this case, the Plaintiffs presented to the court that the “Herb Ingredient from Pueraria Candollei” has been published since 1931, which is merely a write-up of known traditional knowledge at that time.

The 1931 publication discloses the two main ingredients of the product, which are Pueraria Candollei and milk. In Patent No. 8912, the patentee claimed 3 additional ingredients. The Patentee tried to argue that the formula in Patent No. 8912 is different from 1931 publication in this respect. According to the patent specification, the 3 added ingredients comprise (1) sweetener, (2) herbs, and (3) colouring and odour enhancing substances, which could be added from 0%-50%. In addition, the abstract of Patent No. 8912 uses the word “and/or” in respect of (1) sweetener, (2) herbs, (3) colouring and odour enhancing substances. In view of the foregoing, the court found that the addition of these 3 ingredients is optional and the only inevitable ingredients are Pueraria Candollei and milk, which are anticipated by the 1913 publication.

Furthermore, the patent specification of Patent No. 8912 does not include experimental data that show positive results and how these results were achieved. Hence, it was not persuasive to the court that the added ingredients would give significant effect to the product.

From the above fact, the Supreme Court found that the 1931 publication anticipates Patent No. 8912, and its Court Decision No. 4783/2549 (2006) upholds the decision of Central Intellectual Property and International Court (IP Court) to revoke the Patent No. 8912 entitled “Herb Ingredient from Pueraria Candollei” for lack of novelty and inventive step over common general knowledge as evidenced by the 1913 publication.

Therefore, a piece of particular knowledge becomes common general knowledge when it is generally known and accepted without question by skilled persons without inventive ingenuity; in other words, when it becomes part of their common stock of knowledge in the art.