A definition need only be widely accepted rather than universally accepted to form a proper basis for claim construction. Here, for example, although the patentee noted that the definition of the claimed “nanoparticles” and “microparticles” as being between 1 to 1000 nano or micrometers was not in fact standardized, the court found that this definition was nevertheless sufficient because it was at least widely accepted. “[A] definition need not be universally accepted to form a proper basis for claim construction.” It may therefore be best to define or avoid terms that have a widely accepted if not universal meaning other than the meaning intended.

Background / Facts: The patent being asserted here is directed to the anticancer drug product paclitaxel. All asserted claims require a matrix formed of, among other things, “nanoparticles” and “microparticles” of a taxane. The district court construed the term “nanoparticles” to mean “particles that have a mean diameter of between about 1 to 1000 nanometers and less than that of microparticles,” and construed “microparticles” to mean “particles that have a diameter of between about 1 to 1000 microns and greater than that of nanoparticles.” Although the patentee recognized that such definitions may be widely accepted, it asserted that they are not standardized.

Issue(s): Whether a definition must be universally accepted to form a proper basis for claim construction.

Holding(s): No. “[T]he district court described its finding as to how the art understood the terms nanoparticles and microparticles not as ‘universal’ but as ‘widely accepted.’ [] To the extent [the patentee] is arguing the district court committed legal error by basing its construction on an understanding that was less than universally accepted, a definition need not be universally accepted to form a proper basis for claim construction. … Claim construction may ‘involve[] little more than the application of the widely accepted meaning of commonly understood words.’”

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