Under the United States patent system, patents are awarded to inventors who are the first to invent, as opposed to the first to file a patent application. Unless another inventor can show that he conceived of an invention first, and was reasonably diligent in later reducing the invention to practice, the inventor who first reduces the invention to practice is entitled to the patent. “Reduction to practice” can be either constructive, such as by filing a patent application, or actual, such as by constructing a working model or prototype of a product, carrying out the steps of the invented method, or producing the composition of an invented material.
In litigation over competing, sometimes called “interfering,” patent applications for the same invention, evidence of actual reduction to practice is pivotal in establishing the priority of an invention. Such evidence is the “meat on the bones” of a legal case for establishing priority in an interference proceeding. The winning party will have to show that it constructed the claimed embodiment or performed the claimed process, that the embodiment or process functioned for the intended purpose, and that there is sufficient evidence to corroborate the inventor’s testimony as to the first two requirements.
There is no single, exclusive method for marshaling and authenticating evidence for use in a patent priority battle, but the case of the allergy medication ingredient suggests that a meticulous approach is prudent. Examples of practices that should be in place include bound notebooks for inventors, with each page signed and dated in permanent ink not only by the creator of the notebook, but also by a disinterested but informed noninventor; placement of entries in chronological order; and initialing and dating of any corrections. Inventors should record as much detail as possible about their activities and conclusions relating to the invention, and there should be a full explanation for any supplementary materials. Finally, all of this attention to detail and following of procedures could be for naught unless the information is kept in a secure place to which there is authorized access only.