It Is Not Easy to Define the Meaning of a Transitional Phrase
{2:30 minutes to read} In this article, we will look at a transitional phrase and at how the courts decided its meaning. So, what is the meaning and the scope of the closed-ended transitional phrase “consisting of”?
Here are the Facts:
The patent at issue covered a pH-independent controlled release formulation of Mesalazine, useful for the treatment of Crohn’s Disease and Ulcerative Colitis.
The independent claim was directed, inter alia, to an external matrix consisting of compounds selected from a group consisting of unsaturated and/or hydrogenated fatty acid, salts, esters or amides thereof, fatty acid mono-, di-, or triglycerides, waxes, ceramides, and cholesterol derivatives with melting points below 90°C, and wherein the active ingredient is dispersed—both in said the lipophilic matrix and in the hydrophilic matrix.
It is settled law that the transitional phrase “consisting of” excludes any element of step, or ingredient not specified in the claims. In re Gray, 53 F.2d 520, 11 USPQ 255 (CCPA 1931); Ex parte Davis, 80 USPQ 448, 450 (Bd. App. 1948).
The allegedly infringing product included magnesium stearate, which was not part of the elements recited in the Markush group.
The District Court, following a precedent case, found that the presence of components falling outside the scope of the Markush groups did not bar infringement because these components were functionally “unrelated” to the invention. Norian Corp. v. Stryker Corp., 363 F.3d 1321, 1331 (Fed Cir. 2004) (holding that a bone repair kit “consisting of” claimed chemicals was infringed by a bone repair kit including a spatula, in addition to the claimed chemicals, because the presence of the spatula was unrelated to the claimed invention).
The Federal Circuit disagreed and explained, that in Norian Corp., the question was whether adding a spatula to a calcium phosphate chemical kit took the accused product outside the scope of the allegedly infringed patent. And the answer, in Norian Corp., was no, because the spatula was unrelated to the scope of the claims.
So, what does the phrase “consisting of” really exclude from the claims?
In this particular case, the Federal Court found that the magnesium stearate was sufficiently related to the elements of the Markush group because it maintained a lipophilic interaction with the extra-granular space of the matrix. Thus, the magnesium stearate structurally and functionally was related to the invention and its presence violated the “consisting of” requirement of the claims.
With this holding, the Federal Circuit seems to suggest that the holding in Norian Corp. constitutes a “rare exception” which applies only to elements “unrelated” to the invention.
Silvia Salvadori, PhD
(212) 897-1938