In the district court bench trial, the judge "found Abbott’s literal infringement evidence to be unpersuasive, id. at 27, and Abbott’s doctrine of equivalents argument to be barred by prosecution history estoppel." Ignoring this issue, the CAFC focused solely on invaldity.

Sevoflurane is a fast-acting, highly effective inhalation anesthetic. However, pure sevoflurane has a serious problem, unknown at the time of its invention and original shipment: it degrades in the presence of Lewis acids. Lewis acids are essentially defined as any species with an empty electron orbit leading to electron affinity and are common enough that avoiding exposure of sevoflurane to Lewis acids is quite difficult... After investigating the cause of the degradation, Abbott discovered the source of the problem. It also found a solution: water mixed in with sevoflurane will bind to and deactivate Lewis acids, protecting the sevoflurane from the degradation reaction. A deliberate addition of water to sevoflurane ran counter to the conventional wisdom at the time: previously, Abbott had sought to minimize its product’s water content. Abbott filed a patent application on the degradation-preventing combination of water or other “Lewis acid inhibitors” with sevoflurane, which issued as the ’176 patent at issue here.

Patent claims are presumed to be valid, 35 U.S.C. § 282, and the party seeking to show invalidity must prove facts supporting invalidity by clear and convincing evidence. N. Am. Vaccine, Inc. v. Am. Cyanamid Co., 7 F.3d 1371, 1379 (Fed. Cir. 1993).

Baxter cited 5,684,211 as anticipatory, as well as arguing that some of the product Abbott had sold had not degraded, thus meeting the prior art sale bar.

Baxter made two distinct invalidity arguments. It first argued that since some lots of the pre-recall sevoflurane sold by Abbott had not degraded, there had been a prior sale which would bar the patent. The district court found insufficient evidence that those lots had actually been exposed to Lewis acids, making a finding that they had contained water “in an amount effective to prevent degradation” unsupportable. Id. at 44. Baxter’s second argument was that the ’211 patent disclosed a composition of water-saturated sevoflurane that met all the limitations of the asserted claims. Id. at 37-39. The district court noted some of our holdings finding anticipation even where, as here, there was no knowledge at the time of the relevant properties of the prior art. Id. at 40-41 (citing Atlas Powder Co. v. IRECO, Inc., 190 F.3d 1342, 1348-49 (Fed. Cir. 1999); SmithKline Beecham Corp. v. Apotex Corp., 403 F.3d 1331, 1343-44 (Fed. Cir. 2005); Schering Corp. v. Geneva Pharms., Inc., 339 F.3d 1373, 1378-80 (Fed. Cir. 2003)). However, it concluded that the ’211 patent did not anticipate. Id. at 43. That decision was based on its reading of our decision in Bristol-Myers Squibb Co. v. Ben Venue Labs., Inc., in which we noted that “[n]ewly discovered results of known processes directed to the same purpose are not patentable because such results are inherent.” Id. at 42 (quoting 246 F.3d 1368, 1376 (Fed. Cir. 2001) (emphasis added by district court)). It concluded that since the ’211 patent disclosed an “intermediate step” in the manufacture of sevoflurane, “the patent’s purpose was not to produce sevoflurane in its final useable form,” in distinction to the purpose of the ’176 patent, which “involves a final step in production.” Id. at 42. The district court reasoned that since the patents’ purposes were different, the Bristol-Myers Squibb distinction foreclosed a finding of anticipation. Id. at 42-43.

The ’211 patent was applied for in 1995 and awarded to Kawai et al. in November 1997... The parties do not dispute that the ’211 patent predates the ’176 patent for the purposes of 35 U.S.C. § 102, and the facts about what the ’211 patent teaches are in relevant part undisputed. It discloses a technique for purifying sevoflurane for “use[] as a pharmaceutical and particularly as an inhalation anesthetic,” ’211 patent abstract, which involves the addition of water...At the time, however, knowledge of the beneficial nature of a water-sevoflurane mix was wholly lacking in the art. The district court describes the matter succinctly:

[P]rior to [the ’176 patent] invention no one had any idea that Lewis acids had the potential to degrade sevoflurane. Further, no one was aware of the stabilizing effect water would have to prevent Lewis acid degradation. In fact, water was considered an impurity and was removed from sevoflurane to the extent possible during the manufacturing process that included the teachings of the ’211 patent.

Abbott, No. 01-CV-1867, slip op. at 39. Thus, the ’211 patent discloses a particular composition and claims a process for making that composition, but does not teach the advantageous feature of that composition whose discovery led to the patent in suit.

A prior art apparatus cannot be patented, even if new uses of it are found.

Our cases have consistently held that a reference may anticipate even when the relevant properties of the thing disclosed were not appreciated at the time. The classic case on this point is Titanium Metals Corp. v. Banner, 778 F.2d 775 (Fed. Cir. 1985). In Titanium Metals, the applicants sought patent protection on an alloy with previously unknown corrosion resistance and workability properties. Id. at 776. The prior art reference was an article by two Russian scientists that disclosed in a few data points on its graphs an alloy falling within the scope of the claims of the patent in suit. Id. at 776-77. There was no sign that the Russian authors or anyone else had understood the later-discovered features of the alloy thus described. Id. at 780-81. Despite the fact that “the applicants for patent had discovered or invented and disclosed knowledge which is not to be found in the reference,” we held that the Russian article anticipated the asserted patent claims. Id. at 782. The Titanium Metals rule has been repeatedly confirmed and applied by this court. See, e.g., In re Crish, 393 F.3d 1253, 1258-59 (Fed. Cir. 2004) (citing cases; holding asserted claims covering a gene’s nucleotide sequence anticipated where the gene, though not its particular sequence, was already known to the art); In re Cruciferous Sprout Litig., 301 F.3d 1343, 1349-50 (Fed. Cir. 2002) (inventor’s recognition of substances that render broccoli and cauliflower particularly healthy does not permit patent on identifying broccoli seeds or preparing broccoli as a food product); Atlas Powder, 190 F.3d at 1347-1350 (holding asserted claims covering air mixed into an explosive composition anticipated by prior art that necessarily also contained air as claimed, even though benefits of the air were not recognized). Indeed, the rule did not originate with Titanium Metals. See Ansonia Brass & Copper Co. v. Elec. Supply Co., 144 U.S. 11, 18 (1892) (“[T]he application of an old process or machine to a similar or analogous subject, with no change in the manner of application and no result substantially distinct in its nature, will not sustain a patent even if the new form of result had not before been contemplated.”); In re Pearson, 494 F.2d 1399, 1403 (C.C.P.A. 1974) (inventor’s recognition that prior-art compound inhibited defects in peanut plants did not suffice to grant patent protection on that compound); In re Benner, 174 F.2d 938, 942 (C.C.P.A. 1949) (“[N]o provision has been made in the patent statutes for granting a patent upon an old product based solely upon discovery of a new use for such product.”).

The general principle that a newly-discovered property of the prior art cannot support a patent on that same art is not avoided if the patentee explicitly claims that property. “[A] prior art reference may anticipate without disclosing a feature of the claimed invention if that missing characteristic is necessarily present, or inherent, in the single anticipating reference.” Schering, 339 F.3d at 1377 (citing Continental Can Co. v. Monsanto Co., 948 F.2d 1264, 1268 (Fed. Cir. 1991)). “[I]nherent anticipation does not require that a person of ordinary skill in the art at the time would have recognized the inherent disclosure.” Id. (citing Cruciferous Sprout, 301 F.3d at 1351).

Abbott’s objection here is merely that at the time of the ’211 patent, nobody knew that the water-saturated sevoflurane that patent disclosed had the property of resisting the Lewis acid degradation reaction. Just as in Titanium Metals, that lack of knowledge is wholly irrelevant to the question of whether the ’176 patent claims something “new” over the disclosure of the ’211 patent; the claimed property of resistance to degradation is found inherently in the disclosure.

For process claims, however, "new uses of known processes may be patentable." In this case, though, it was the same use.

The district court nonetheless found the patent valid due to the purpose-based distinction we drew in Bristol-Myers Squibb. Abbott, No. 01-CV-1867, slip op. at 42-43 (citing 246 F.3d at 1376). As a threshold matter, we note that that distinction is applicable only to process claims. Bristol-Myers Squibb states that “new uses of known processes may be patentable,” citing in support the definition of “process” found at 35 U.S.C. § 100(b). 246 F.3d at 1376. The case does not speak to composition claims; the district court therefore committed legal error by applying it to sustain the validity of those claims of the ’176 patent that cover a mixture of sevoflurane and water. As to the ’176 patent’s process claims, we agree that Bristol-Myers Squibb needs to be considered, but we disagree with the concept that the processes described in the ’176 patent are not “directed to the same purpose,” id., under the meaning of Bristol-Myers Squibb. Both the ’211 and the ’176 patents disclose methods which help to ensure that sevoflurane will be of high purity at the time it is administered to patients... We hold today, as we did in Bristol-Myers Squibb, that “the claimed process here is not directed to a new use; it is the same use.” Id.; see also Catalina Mktg. Int’l, Inc. v. Coolsavings.com, Inc., 289 F.3d 801, 809-10 (Fed. Cir. 2002) (explaining that an inventor may not obtain a patent on a process having the same steps as a prior art process, in which the new process merely identifies a new, advantageous property of the prior art process).

That a claimed process is found as an intermediate step in the prior art could only give protection where "commercial finality" is claimed; that seems a bizarre loophole.

We also do not find it material that the district court found the anticipating method in the ’211 patent to be “an intermediate step” in the manufacture of sevoflurane. Abbott, No. 01-CV-1867, slip op. at 42. The product of that method was an anesthetic sevoflurane composition with sufficient water to prevent Lewis acid degradation—exactly what is claimed by the ’176 patent. Commercial finality is not claimed.