Using flavorant to prevent pseudoephedrine misuse found to be obvious. IN RE: RAJAGOPALAN

To get a patent on an invention in the United States, an inventor must file a patent application with the United States Patent and Trademark Office. For the patent application to be granted, the invention must meet all of the requirements of United States patent law. One of the requirements that an invention must meet to be granted a patent is that the invention cannot be obvious. This may seem like a simple requirement, but the term obvious has a special definition in patent law.

Obviousness under 35 U.S. Code § 103 is a question of law based on underlying findings of fact. Those underlying findings of fact include: (1) “the scope and content of the prior art,” (2) “differences between the prior art and the claims at issue,” (3) “the level of ordinary skill in the pertinent art,” and (4) the presence of evidence of secondary considerations, such “as commercial success, long felt but unsolved needs, failure of others,” and unexpected results.

Whether an invention is obvious is an objective test based on the prior art and a person having ordinary skill in that art. Prior art is the sum of all knowledge in a given field of technology. Research papers, granted patents, patent applications, and other forms of printed publications are all examples of prior art. The person of ordinary skill in the art is a hypothetical person who is presumed to have known the relevant art at the time of the invention.

Whether or not an invention will be found obvious can be a complicated analysis therefore it is helpful to review case law to better understand how courts apply the obviousness standard.

IN RE: RAGHAVAN RAJAGOPALAN, 2020-1956 (C.A.F.C. 2021) is an example of a patent application which was rejected because it was found to be obvious.

This case centers around U.S. Patent Application No. 14/499,191, entitled “Prevention of Illicit Methamphetamine Manufacture from Pseudoephedrine Using Food Flavor Excipients.” Pseudoephedrine is a common over the counter treatment for colds. The pseudoephedrine in cold medicine can be extracted and used to manufacture illicit drugs. The application discloses a pseudoephedrine composition that prevented cold medicine from being converted into illicit drugs. Specifically, it discloses a combination of pseudoephedrine with a food-flavoring additive that blocks the formation of methamphetamine. These food-flavoring additives are referred to in the ’191 application as “organoleptic agents.”

The patent examiner rejected the application as obvious in view of three prior art references: Giamalva, Adams, and Takakura. Giamalva is a published patent application, U.S. Patent Application Publication No. 2007/0243140 which teaches adding a compound which exhibits a characteristic odor and interferes with the conversion of pseudoephedrine to methamphetamine. Adams is a journal article that teaches pyrazines are nitrogen-containing compounds that are used as flavoring agents in foods. Takakura is a published patent application, U.S. Patent Application entitled “Flavoring Material.” Takakura teaches that thiazoles are known organoleptic compounds. The PTAB affirmed the examiner’s rejections of the claims as obvious in light of Giamalva combined with Adams or with Adams and Takakura. The applicant appealed the PTAB’s decision to the Court of Appeals for the Federal Circuit.

On appeal the applicant argued that the prior-art references do not teach using the organoleptic additive in an “effective amount.” The ’191 application defines effective amount as one that sufficiently inhibits the formation of methamphetamine to be “less than about 25%” of the formed composition.

The Federal Circuit found that Giamalva did teach several ratios which include the “effective amount” disclosed by the ’191 application. The Federal Circuit also found that Giamalva teaches using an odorant to interfere with the chemical conversion of pseudoephedrine, Adams discloses particular odorants, and Takakura discloses particular flavorants. The Federal Circuit ultimately held that the PTAB’s decision was supported by substantial evidence and affirmed that rejection of the ‘191 application for obviousness.

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