This is a patent infringement case under the Hatch-Waxman Act. Apotex, Inc. and Apotex Corp. (collectively “Apotex”) appeal the grant of summary judgment by the United States District Court for the Northern District of California that the patent held by Roche Palo Alto LLC and Allergan, Inc. (collectively “Roche”) is valid and infringed by the formulation covered by Apotex’s abbreviated new drug application (“ANDA”).
Roche Palo Alto, LLC v. Apotex, Inc.,
I
A
Roche is the owner of U.S. Patent No. 5,110,493 (“the '493 patent”), which is directed to a drug formulation for treatment of eye inflammation, such as that caused by glaucoma, conjunctivitis, eye surgery, or eye injury. '493 patent, col. 1,11. 14-28. The formulation contains a non-steroidal anti-inflammatory drug (“NSAID”), such as ketorolac tromethamine (“KT”); a quaternary ammonium preservative, such as benzalkonium chloride (“BAC”); and the nonionic surfactant, octoxynol 40 (“O40”). Id., col. 3,11. 13-19, col. 4,11. 20-41. Claim 1 is representative:
*1375 An opthalmologically acceptable non-steroidal anti-inflammatory drug formulation, comprising:
an opthamologically acceptable non-steroidal anti-inflammatory carboxyl group-containing drug in an effective amount for ophthalmic treatment between 0.001 % and 10.00% wt/vol;
a quaternary ammonium preservative in an antimicrobially effective amount between 0.001% and 1.0% wt/vol;
an ethoxylated alkyl phenol that conforms generally to the formula: C8H17 C6H4(OCH2-CH2)n OH where n has an average value of 40 [O40] in a stabilizing amount between 0.001% and 1.0% wt/vol; and an aqueous vehicle q.s. to 100%.
Dependent claim 7 further includes sodium chloride (“NaCl”) at a concentration of 0.79% wt/vol.
The last limitation in claim 1, requiring the presence of 04o> was added in response to the examiner’s obviousness rejection over several prior art references. Accompanying the claim amendment, the applicants submitted the Lidgate Declaration, which stated that O40 produced unexpected results over other nonionic surfactants, such as 03 and 0B. Specifically, the declaration stated that O40 produced a clear solution while the others did not. The examiner allowed the claims based on the unexpected results of O40.
Over the years, Apotex filed two different ANDAs on two different generic drug formulations, each containing a paragraph IV certification that the '493 patent is invalid, unenforceable, or will not be infringed by the generic version of the drug. In 2001, Apotex filed its first ANDA (“ANDA-1”), directed to a generic version of Roche’s ACULAR®. Subsequently, in 2005, Apotex filed its second ANDA (“ANDA-2”), directed to a generic version of Roche’s ACULAR®LS. The two formulations differ in their compositions as follows:
ANDA-1 (ACULAR®) ANDA-2 (ACULAR0LS)
KT 0.5% 0.4%
BAC 0.01% 0.0063%
O4o 0.01% 0.004%
NaCl 0.8% 0.8%
Notably, the concentration of O40 is reduced in the ANDA-2 formulation as compared to the ANDA-1 formulation, but both are within the range claimed in claim 1 of the '493 patent. The concentration of NaCl is identical in the two formulations and encompassed by at least claiml of the patent.
B
On June 6, 2001, Roche’s predecessor, Syntex (U.S.A.) LLC (“Syntex”) sued Apo-tex for infringement of the '493 patent based on the ANDA-1 formulation. The district court issued a claim construction order. Syntex (U.S.A.) LLC v. Apotex, Inc., No. 01-2214 (N.D.Cal. Nov. 19, 2002). Because claim 1 of the '493 patent expressly states a concentration range for O40, the court held that the claim term “stabilizing amount” is merely a statement of intended result and not a claim limitation. Id., slip op. at 9. Thereafter, the district court granted Syntex’s motion for partial summary judgment that the ANDA-1 formulation literally infringed the '493 patent. Syntex (U.S.A.) LLC v. Apotex, Inc., No. 01-2214, slip op. at 4-5 (N.D.Cal. Mar. 19, 2003). Following a bench trial on Apotex’s invalidity defenses of lack of utility, lack of enablement, indefiniteness, and obviousness, and its unen-forceablity defense based on inequitable conduct, the court held that the '493 patent was both valid and enforceable. Syntex (U.S.A.) LLC v. Apotex, Inc., No. 01-2214 (N.D.Cal. Dec. 29, 2003) (“Syntex I”).
*1376
On May 18, 2005, this court affirmed the district court’s claim construction and holding of no inequitable conduct, but reversed its holding of validity based on non-obviousness.
Syntex (U.S.A.) LLC v. Apotex, Inc.,
One day after our mandate issued, the Supreme Court issued its opinion on obviousness in
KSR International Co. v. Teleflex Inc.,
— U.S. -,
C
On May 24, 2005, Roche sued Apotex for infringement of the '493 patent based on the ANDA-2 formulation. Apotex asserted the defenses of non-infringement; invalidity under 35 U.S.C. §§ 101, 103, and 112; and unenforceability due to inequitable conduct. Thereafter, Roche filed a motion for summary judgment that the ANDA-2 formulation infringes the '493 patent and that the validity and unenforce-ability defenses should be barred based on the earlier Syntex litigation (Syntex I, Syntex II, and Syntex III) under the doctrines of issue preclusion and claim preclusion. Apotex countered by arguing that the ANDA-2 formulation escapes infringement under the reverse doctrine of equivalents. Apotex further averred that the doctrines of issue preclusion and claim preclusion were inapplicable because the ANDA-2 formulation and the ANDA-1 formulation were distinct, and the change in law exception, in view of KSR, prevented application of those doctrines.
On September 11, 2007, the district court granted Roche’s motion for summary judgment.
Roche Palo Alto LLC v. Apotex, Inc.,
The district court also held that Apotex’s invalidity and unenforceablity arguments, with the exception of obviousness, were prevented by issue preclusion because the invalidity of the '493 patent had already been asserted against Roche in the ANDA-1 litigation. Id. at 994-95. Following Ninth Circuit precedent, the court held that issue preclusion barred Apotex from challenging validity on any ground, even grounds that had not been raised in the first litigation. Id. at 995. With respect to the validity challenge on obviousness grounds, the court did not reach *1377 whether the Supreme Court decision in KSR constituted a change in law necessitating an exception to issue preclusion because it held that such a challenge was prevented by claim preclusion. Id. at 997.
With respect to claim preclusion, the district court held that the two accused products, ANDA-1 and ANDA-2, are “essentially the same,” and thus each of the invalidity claims in the ANDA-2 litigation was prevented by claim preclusion. Id. at 997-99. The court further held that there is no “change of law” or fairness exception to claim preclusion to prevent its application despite the intervening KSR decision. Id. at 999-1000. Hence, the court held that Apotex’s invalidity and unenforceability affirmative defenses were barred by claim preclusion. Id. at 1000.
Apotex appeals. We have jurisdiction pursuant to 28 U.S.C. § 1295(a)(1).
II
We review a grant of summary judgment of non-infringement de novo, reapplying the standard used by the district court.
Innogenetics, N.V. v. Abbott Labs.,
The determination of infringement is a two-step process, wherein the court first construes the claims and then determines whether every claim limitation, or its equivalent, is found in the accused device.
In re Gabapentin Patent Litig.,
We review the district court’s application of the doctrine of claim preclusion de novo.
Acumed LLC v. Stryker Corp.,
III
Apotex does not dispute that the ANDA-2 formulation falls within the literal scope of claim 1 of the '493 patent. Instead, Apotex argues that the district court erred in failing to find non-infringement by the ANDA-2 formulation under the reverse doctrine of equivalents.
The reverse doctrine of equivalents is an equitable doctrine designed “to prevent unwarranted extension of the claims beyond a fair scope of the paten-tee’s invention.”
Scripps Clinic & Research Found. v. Genentech, Inc.,
[W]here a device is so far changed in principle from a patented article that it performs the same or similar function in a substantially different way, but nevertheless falls within the literal words of the claim, the [reverse] doctrine of equivalents may be used to restrict the claim and defeat the patentee’s action for infringement.
Graver Tank & Mfg. Co. v. Linde Air Prods. Co.,
Apotex, relying on the declaration of its scientific expert, Dr. Mitra, argues that a person of ordinary skill in the art would recognize that the “principle” of the '493 patent is the use of O40 in an amount sufficient to cause the formation of micelles and thereby provide robust stability to the formulation by preventing interactions between KT and BAC. Apotex contends that such a principle is supported by the prosecution history of the '493 patent application in that the examiner ultimately allowed the claims based on the Lidgate Declaration, demonstrating the unexpected results of formulations containing O40. According to Apotex, it is of no consequence that the claims, specification, and prosecution history do not mention “micelles” and that the district court construed “stabilizing amount” to be an intended result, not a claim limitation, since a person of ordinary skill in the art knows that O40 stabilizes the formulation by forming micelles. In contrast to the patented invention, Apotex asserts, the concentration of O40 in the ANDA-2 formulation is far below the concentration required to form micelles. Instead, in the ANDA-2 formulation, NaCl acts to ionieally shield KT and BAC, preventing them from interacting. Thus, Apotex asserts, the ANDA-2 formulation stabilized by a completely different ingredient and mechanism, and functions in “substantially different way” from the formulation claimed in the '493 patent.
Apotex contends that because it has succeeded in making a prima facie showing of non-infringement under the reserve doctrine of equivalents, it is incumbent upon Roche to rebut that prima facie case. According to Apotex, Roche has presented only attorney arguments, not scientific evidence or expert testimony, to rebut Apo-tex’s evidence. Even if the attorney arguments are accepted as contrary evidence, Apotex contends that there is at least a genuine issue of material fact in dispute not amenable to resolution on summary judgment. Thus, Apotex asserts, the district court erred by not drawing all inferences in favor of Apotex and not finding a genuine issue of material fact.
We agree with the district court that Apotex has failed to set forth a prima facie case of non-infringement under the reverse doctrine of equivalents because it does not properly establish the principle of the '493 patent. The “principle” or “equitable scope of the claims” of the patented invention is determined in light of the specification, prosecution history, and the prior art.
Scripps Clinic,
As the district court noted, there is no mention of “micelle” in the claims, specification, or prosecution history of the '493 patent. Further, we previously held that there was no error in the district court’s construction of claim 1 of the '493 patent to regard “stabilizing amount” not as a claim limitation, but as an intended result, given that the claim expressly sets forth a concentration range for O40.
Syntex II,
The claims and the specification clearly encompass formulations comprising a broad concentration range of O40, from 0.001% to 10% wt/vol. 1 Example 3 discloses a formulation containing O40 at a concentration of 0.004% wl/vol, the same concentration as in the ANDA-2 formulation.
For these reasons, we agree with the district court that Apotex did not properly support its alleged “principle” of the patented invention and consequently failed to make out a prima facie case of non-infringement under the reverse doctrine of equivalents. Roche, therefore, was not required to rebut the prima facie case. Accordingly, we find no error by the district court in rejecting Apotex’s defense under the reverse doctrine of equivalents and in granting summary judgment of literal infringement of the claims of the '493 patent by the ANDA-2 formulation.
IV
Apotex next asserts that the district court erred in holding that its validity challenges to the '493 patent were barred by claim preclusion. Under Ninth Circuit law, claim preclusion applies where: “(1) the same parties, or their privies, were involved in the prior litigation, (2) the prior litigation involved the same claim or cause of action as the later suit, and (3) the prior litigation was terminated by a final judgment on the merits.”
Cent. Delta Water Agency v. United States,
Apotex does not dispute that the
Syntex
litigation
(Syntex I, Syntex II,
and
Syntex
III) ended in a final judgment and that it involved the same parties or their privies. Rather, Apotex contests only the district court’s holding that the instant litigation, pertaining to its ANDA-2 formulation, and the
Syntex
litigation, pertaining to its ANDA-1 formulation, involved the same claim or cause of action. Whether two claims for infringement constitute the “same claim” is an issue particular to patent law and thus Federal Circuit law applies.
Acumed LLC v. Stryker Corp.,
Apotex avers that Roche had the burden of establishing that the ANDA-2 formulation at issue in the instant litigation and the ANDA-1 formulation at issue in the Syntex litigation were “essentially the same,” yet Roche did not present any expert testimony or other evidence to that effect. In contrast, Apotex provided the Mitra Declaration, which shows that the concentration of O40 in the ANDA-2 formulation is insufficient to form micelles and thus the ANDA-2 formulation is materially different from the ANDA-1 formulation. Apotex further contends that the ANDA-2 formulation is not “essentially the same” as the ANDA-1 formulation because the two formulations are stabilized by completely different ingredients and mechanisms. Whereas micelle formation by O40 stabilizes the ANDA-1 formulation, ionic shielding by NaCl stabilizes the ANDA-2 formulation. According to Apo-tex, the fact that it had to file a separate ANDA for the ANDA-2 formulation is additional evidence that the ANDA-2 formulation is materially different from the ANDA-1 formulation. Thus, Apotex asserts that there is at least a genuine issue material fact as to whether the two ANDA formulations are “essentially the same.”
We find no error in the district court’s analysis. The court determined that the ANDA-1 formulation and the ANDA-2 formulation are “essentially the same” because any differences between them are unrelated to the claims of the '493 patent. Though the court recognized that there are differences in the concentrations of the ingredients in the ANDA-1 and ANDA-2 formulations, it also realized that all of the concentrations are well within the ranges claimed in the '493 patent. The fact that they are stabilized by different mechanisms, even if true, is irrelevant because both formulations are encompassed by the claims of the '493 patent. Thus, any difference in composition between the two formulations is merely colorable and the two formulations are “essentially the same.”
In the alternative, Apotex asserts that principles of fairness should prevent application of claim preclusion given the change in the law of obviousness following the Supreme Court’s opinion in KSR. In essence, Apotex argues that claim preclusion is not absolute and that this is a case where an exception to the finality rule should apply.
The district court, however, correctly recognized that there is no “change of law” or fairness exception to prevent application of claim preclusion.
Federated Dep’t Stores, Inc. v. Moitie,
As the Supreme Court explained:
Nor are the res judicata consequences of a final, unappealed judgment on the merits altered by the fact that the judgment may have been wrong or rested on a legal principle subsequently overruled in another case.... We have observed that “[t]he indulgence of a contrary view would result in creating elements of uncertainty and confusion and in undermining the conclusive character of judgments, consequences which it was the very purpose of the doctrine of res judi-cata to avert.”
Federated Dep’t Stores,
Accordingly, the district court did not err in concluding that Apotex’s validity challenges to the '493 patent were barred by the doctrine of claim preclusion. 2
V
For the foregoing reasons, we affirm the district court’s grant of Roche’s motion for summary judgment that the ANDA-2 formulation literally infringes the claims of the '493 patent and that Apotex’s invalidity and unenforceability challenges to the '493 patent are barred by claim preclusion.
AFFIRMED.
Notes
. Apotex asserts that, if the '493 claims are construed to cover the entire claimed O40 concentration range, then the claims are invalid under 35 U.S.C. § 112, first paragraph, because they are not enabled throughout their full scope. Alternatively, Apotex argues that, if the claims are so construed, they are invalid as obvious under 35 U.S.C. § 103, because not all concentrations form micelles and thus produce unexpected results. Such arguments go to the validity of the claims of the '493 patent. For the reasons discussed below, we agree with the district court that such validity challenges are barred by claim preclusion.
. Because we hold that the district court properly determined that Apotex's validity challenges were barred by claim preclusion, we need not reach whether the district court lawfully applied the doctrine of issue preclusion to bar the same validity challenges.