United States Court of Appeals for the Federal Circuit 

04-1252 

SYNTEX (U.S.A.) LLC and ALLERGAN, INC., 

Plaintiffs-Appellees, 

v. 

APOTEX, INC., APOTEX CORP., 

and NOVEX PHARMA, 

Defendants-Appellants. 

David J. Harth, Heller Ehrman White & McAuliffe LLP, of Madison, Wisconsin, 

argued for plaintiffs-appellees. With him on the brief were Alexander L. Brainerd, Keith R. 

Weed, and Olga Rodstein, of Menlo Park, California, and Christine Saunders Haskett, of 

San Francisco, California. 

Manny D. Pokotilow, Caesar, Rivise, Bernstein, Cohen & Pokotilow, LTD., of 

Philadelphia, Pennsylvania, argued for defendants-appellants. With him on the brief were 

Robert S. Silver, Alan H. Bernstein, Mona Gupta and William J. Castillo. Of counsel on the 

brief was Ronald S. Lemieux, Squire, Sanders & Dempsey L.L.P., of Palo Alto, California. 

Appealed from: United States District Court for the Northern District of California 

Judge Martin J. Jenkins 

 
United States Court of Appeals for the Federal Circuit 

04-1252 

SYNTEX (U.S.A.) LLC and ALLERGAN, INC., 

Plaintiffs-Appellees, 

v. 

APOTEX, INC., APOTEX CORP., 

and NOVEX PHARMA, 

Defendants-Appellants. 

________________________ 

DECIDED: May 18, 2005 

________________________ 

Before CLEVENGER, GAJARSA, and PROST, Circuit Judges. 

Opinion for the court filed by Circuit Judge GAJARSA. Concurring opinion filed by 

Circuit Judge PROST. 

GAJARSA, Circuit Judge. 

 Apotex, Inc., Apotex Corp. and Novex Pharma (collectively "Apotex") appeal from 

the final judgment of the United States District Court for the Northern District of 

California, which, after a bench trial, held U.S. Patent No. 5,110,493 (the "'493 patent") 

owned by Syntex (U.S.A.) LLC not invalid, enforceable, and infringed by Apotex's 

Abbreviated New Drug Application ("ANDA"). Allergan, Inc., Syntex's distributor, has 

exclusive rights to manufacture the commercial embodiment of the '493 patent 
marketed under the trademark ACULAR.1

 Syntex (U.S.A.) LLC v. Apotex, Inc., No. 01-

CV-2214 (January 27, 2004). Because we find the district court committed legal error in 

establishing certain factual predicates to its non-obviousness determination, we reverse 

the judgment of validity and remand for further consideration consistent with this 

opinion. 

BACKGROUND 

A. The Patents and Prosecution History

The '493 patent, entitled "Ophthalmic NSAID Formulations Containing a 

Quaternary Ammonium Preservative and a Nonionic Surfactant," claims a formulation 

for sterile, preserved eye drops to treat eye inflammation such as that caused by

conjunctivitis or eye surgery. 

The '493 patent teaches combining a nonsteroidal anti-inflammatory drug 

("NSAID") such as ketoralac tromethamine ("KT") and a quaternary ammonium

preservative such as benzalkonium chloride ("BAC") with a surfactant such as octoxynol 

40. The NSAID is the active ingredient for reducing eye inflammation. The quaternary 

ammonium preservative, in turn, kills any bacteria introduced into the eye during

administration of the NSAID. However, quaternary ammonium preservatives, such as 

BAC, do not always mix well with NSAIDs. Neither ingredient is water soluble, and the 

two active ingredients may react with each other to form complexes when mixed. 

These complexes will eventually cause the mixture to look cloudy or lose its 

antibacterial properties. 

 1

 Hereinafter, the appellees are collectively referred to as "Syntex."

ACULAR is a trademark owned by Syntex, Inc.

04-1252 2
The chemical arts often solve this type of mixing problem by using surfactants. A 

surfactant is a "surface active agent" used to make otherwise insoluble chemicals

soluble in water. The '493 patent claims to solve the complex formation problem by

adding octoxynol 40, a surfactant, to the KT/BAC mixture. 

The '493 patent claims ophthalmic formulations (eye drops) useful for treating 

eye inflammation, methods of using eye drops to treat eye disease, and preservative 

systems for use in eye drops. The claims of the '493 patent fall into three categories: 

claims 1 to 7 are composition claims, claims 8 to 14 are method claims, and claims 15 

and 16 recite a "preservative system." Claims 1, 8, and 15 are independent claims, the 

others are all dependent. Claim 1, the basic embodiment of the compound, provides: 

1. An ophthalmologically acceptable non-steroidal anti-inflammatory drug 

formulation, comprising: 

an opthalmologically acceptable non-steroidal anti-inflammatory carboxyl

group-containing drug in an effective amount for ophthalmic treatment 

between 0.001% and 10.0% wt/vol; 

a quaternary ammonium preservative in an antimicrobially effective 

amount between 0.0001% and 1.0% wt/vol; 

an ethoxylated alkyl phenol that conforms generally to the formula 

C8H17C6H4(OCH2CH2)nOH2

 where n has an average value of 40 in a 

stabilizing amount between 0.001% and 1.0% wt/vol; and an aqueous

vehicle q.s. to 100%. 

'493 patent, col. 8, ll. 42-55. 

The '493 patent issued from U.S. Patent Application No. 07/624,027 ("the '027 

application"), which was filed on December 7, 1990. The '027 application was a 

continuation of U.S. Patent Application No. 07/096,173 ("the '173 application") filed on 

 2

 This is the formula for octoxynol 40. 

04-1252 3
September 11, 1987. The two applications were reviewed by different examiners at the

Patent and Trademark Office ("PTO"). 

Each examiner rejected the application before him as obvious in view of U.S. 

Patent No. 4,349,563 to Gilbert and U.S. Patent No. 4,559,343 to Han in view of 

McCutcheon's Emulsifiers and Detergents p.154 (1982) ("McCutcheon's"). U.S. Patent

No. 4,454,151 to Waterbury, another patent assigned to Syntex, was listed on the '493 

patent as prior art, but was not cited by the examiner in his obviousness rejection. The 

prior art patents Waterbury, Gilbert, and Han all teach ophthalmic formulations

containing NSAIDs, quaternary preservatives, and nonionic surfactants to stabilize the

formulation. While Waterbury, Gilbert, and Han do not teach the specific use of 

octoxynol 40, they do teach using the general class of water-soluble nonionic 

surfactants as stabilizers. Waterbury and Gilbert teach the use of polysorbate 80.3

 

McCutcheon's, a comprehensive directory of emulsifiers and detergents, teach that

octoxynol 40 was a known stabilizer. According to both examiners, it was well known in 

the art that surfactants such as octoxynol 40 have a stabilizing effect on ophthalmic

compounds containing NSAIDs.4

 The examiner reviewing the '027 continuation 

application rejected what has become claim 1 on the grounds that "[t]he mere 

substitution of one [surfactant] for another . . . is not deemed a patentable distinction in 

the absence of a showing of some unobvious result." 

 3 Polysorbate 80 is sometimes referred to as "tween 80" by the PTO, district 

court, and the parties. For the purposes of this opinion, all references to tween have

been replaced with polysorbate 80. 

4 Consequently, within the context of this art, surfactants are sometimes 

referred to as stabilizers.

04-1252 4
Syntex responded to that rejection by asserting that it had provided acceptable 

data demonstrating results superior to the formulations disclosed by the Han and Gilbert 

references. Syntex supported its superior results claim with a declaration from Deborah 

M. Lidgate ("Lidgate"), one of the named inventors. In the declaration, Lidgate stated 

that "octoxynol 40, and not octoxynol 3 or octoxynol 5, is suitable to use with

benzalkonium chloride to prepare a preservative system for an ophthalmic formulation, 

or to prepare an ophthalmic formulation, of the present application." In presenting her

findings of superior results, Lidgate excluded the additional experimental data that she 

had developed showing octoxynol 12.5 to be a surfactant capable of stabilizing a

KT/BAC formulation. 

Following this submission, the examiner allowed the application to issue, stating 

that Syntex had "overcome the prior art rejections . . . by showing that unexpected 

results are obtained when one uses [octoxynol 40]. These results are unobvious

because one of ordinary skill in the art would not have known that one surfactant would

outperform other surfactants." The patent issued on May 5, 1992. 

Syntex markets the patented ophthalmic formulation as ACULAR. ACULAR 

embodies the claims of the '493 patent and has been approved by the Food and Drug 

Administration ("FDA"). From 1993 to 2001, ACULAR captured a substantial market

share for ophthalmic anti-inflammation drugs. 

04-1252 5
B. The Hatch-Waxman Amendments

The Hatch-Waxman Amendments5 to the Federal Food, Drug, and Cosmetic Act 

permit an applicant to file an ANDA with the FDA requesting approval of a bioequivalent 

("generic") version of a drug that is already listed by the FDA as approved for safety and 

effectiveness without having to submit additional safety and efficacy data. See 21 

U.S.C. § 355(j)(2)(A). The overall scheme of the Hatch-Waxman Amendments is

described in detail in our decisions in Mylan Pharmaceuticals, Inc. v. Thompson, 268 

F.3d 1323 (Fed. Cir. 2001) and Andrx Pharmaceuticals, Inc. v. Biovail Corp., 276 F.3d 

1368 (Fed. Cir. 2002) and need not be repeated here. For the purposes of this opinion 

it suffices to know that an ANDA may be filed for drugs currently protected by patents 

and listed in the FDA's Orange Book. Mylan Pharmaceuticals, Inc., 268 F.3d at 1325-

26. In its filing, the applicant must certify either (1) that it will not market its drug prior to

the expiration of the relevant patents, or (2) that the relevant patents "are invalid or will 

not be infringed by the manufacture, use or sale of the new drug for which the ANDA is

submitted." 21 U.S.C. § 355(j)(2)(A)(vii)(IV). An ANDA applicant filing its application

with the FDA and making a Section IV certification must notify the holder of the patent,

who may then bring an action against the applicant for infringement under 35 U.S.C.

§ 271(e)(2). See 21 U.S.C. §§ 355(j)(2)(B)(i) and (j)(5)(B)(iii). In its notice the applicant 

must include "a detailed statement of the factual and legal basis [sic] of the opinion of

the applicant that the patent is invalid or will not be infringed." 21 U.S.C.

§ 355(j)(2)(B)(iv). Such a notice can state that the patent is invalid on the basis of 

 5

 The Hatch-Waxman Amendments were enacted as a part of the Drug 

Price Competition and Patent Term Restoration Act of 1984, Pub. L. No. 98-417, 

codified at 21 U.S.C. §§ 355 and 360cc, and 35 U.S.C. §§ 156, 271, 282. 

04-1252 6
anticipation, obviousness or non-enforceable for patent misuse or inequitable conduct. 

Submission of an ANDA is an act of patent infringement if the ANDA seeks approval to 

manufacture, use, or sell a drug that is claimed in a patent or the use of which is

claimed in a patent. 35 U.S.C. § 271(e);6

 Eli Lilly & Co. v. Medtronic, Inc., 496 U.S.

661, 676 (1990) ("The function of [35 U.S.C. § 271(e) is] to define a new (and somewhat

artificial) act of infringement for a very limited and technical purpose that relates only to 

certain drug applications."). 

C. The District Court Proceedings

Apotex manufactures generic pharmaceuticals. On April 25, 2001, Apotex 

notified Syntex that it had filed ANDA 76-109 with the FDA to market a generic version 

of ACULAR including a Section IV certification. In its notice to Syntex, Apotex stated 

that it believed the '493 patent to be invalid on the grounds of obviousness and 

inequitable conduct, and not infringed by Apotex's proposed generic version of

ACULAR. On June 6, 2001, Syntex filed suit against Apotex for patent infringement. 

 6

 35 U.S.C. § 271(e) provides in relevant part: 

(2) It shall be an act of infringement to submit- 

(A) an application under section 505(j) of the Federal Food, Drug, and 

Cosmetic Act or described in section 505(b)(2) of such Act for a drug 

claimed in a patent or the use of which is claimed in a patent, . . . if the 

purpose of such submission is to obtain approval under such Act to 

engage in the commercial manufacture, use, or sale of a drug or

veterinary biological product claimed in a patent or the use of which is

claimed in a patent before the expiration of such patent. 

An ANDA is an application under section 505(j) of the Federal Food, Drug, and 

Cosmetic Act. 

04-1252 7
The district court held a Markman hearing and issued a Claim Construction 

Order. In construing two disputed claim terms7 of the '493 patent, the district court ruled 

that the term "in a stabilizing amount" in claim 1 was not a limitation, but merely 

described the intended results of using octoxynol 40 in an "amount between 0.001%

and 1.0% wt/vol." '493 patent, col. 8, line 55. The claim term makes clear that 

combining the recited ingredients in the claimed weight to volume ratio will stabilize the

compound. 

Syntex moved for summary judgment of infringement based upon the court's

specific claim construction. Apotex did not oppose Syntex's motion. The district court

compared the claims of the '493 patent with the drug formulation and uses set forth in 

Apotex's ANDA 76-109 application and determined that there was no factual dispute. 

The district court found that the generic version of ACULAR identified in the ANDA 76-

109 submission would infringe each claim of the '493 patent, and granted Syntex's

motion for partial summary judgment that Apotex had literally infringed each claim of the 

'493 patent. 

After a bench trial on the issues of invalidity and unenforceablity, the district court 

restated its determination that Apotex's proposed generic version of ACULAR infringed

all of the claims of the '493 patent. The district court found that ACULAR is coextensive 

with the method claims of the '493 patent. The district court also determined that

Apotex's proposed generic drug is virtually identical to ACULAR in its composition,

preservative system, and intended uses. On the basis of these findings, the district

court reiterated that the formulation defined by ANDA 76-109 directly infringed claims 1-

 7

 The district court's conclusion that the claim term "antimicrobially effective"

is not a claim limitation is not being appealed. 

04-1252 8
6, 8-13, and 15-16 of the '493 patent. The district court further stated that claims 7 and

14 were infringed under the doctrine of equivalents.8

 

The district court held that the '493 patent was not invalid, rejecting Apotex's

invalidity arguments based on obviousness. Moreover, the district court concluded that 

Syntex had overcome the PTO examiner's obviousness objection by making a showing 

that the prior art taught away from the use of octoxynol 40 in ophthalmic solutions 

containing BAC and NSAIDs, and that the use of octoxynol 40 generated unexpected 

results. The district court also found that the substantial success of ACULAR on the 

market confirmed that the '493 patent claims were non-obvious. Finally, the district 

court found no inequitable conduct. The court rejected Apotex's contentions that Syntex 

had affirmatively misrepresented the unexpected nature of octoxynol 40's ability to 

stabilize the KT/BAC combination by deliberately withholding test results concerning the

ability of octoxynol 12.5 to accomplish the same objectives as the claimed surfactant. 

The district court found that the test results concerning octoxynol 12.5 were not

material, and that Syntex lacked intent to deceive the PTO. 

Apotex appeals the district court's claim construction ruling, its judgment of 

infringement, its non-obviousness determination, and its finding of no inequitable 

conduct. We have jurisdiction pursuant to 28 U.S.C. § 1295(a)(1). 

 8 Claims 7 and 14, the district court observed, specified a sodium chloride 

concentration of 0.79%. The ANDA formulation contains 0.8% sodium chloride. The 

court concluded this minor difference would not permit the ANDA formulation to escape 

infringement under the doctrine of equivalents. 

04-1252 9
DISCUSSION

A. Standard of Review

This court reviews de novo the grant of summary judgment. Genzyme Corp. v. 

Transkaryotic Therapies, Inc., 346 F.3d 1094, 1096 (Fed. Cir. 2003). Summary 

judgment is appropriate when there are no genuine issues of material fact and the 

moving party is entitled to judgment as a matter of law. Fed. R. Civ. P. 56(c); Anderson 

v. Liberty Lobby, Inc., 477 U.S. 242, 247-48 (1986). A determination of patent

infringement consists of two steps: (1) the court must first interpret the claim, and (2) it 

must then compare the properly construed claims to the allegedly infringing device. 

See Cybor Corp. v. FAS Techs., Inc., 138 F.3d 1448, 1454 (Fed. Cir. 1998) (en banc). 

Claim construction, the first step, is a matter of law that this court reviews de novo. Id.

at 1456. Generally, the second step is a factual question that we review for clear error. 

Bai v. L & L Wings, Inc., 160 F.3d 1350, 1353 (Fed. Cir. 1998). However, factual

inferences that are material to the grant of a summary judgment are not accorded such 

deference—they are reviewed to ascertain whether there is a genuine issue of material 

fact. Lemelson v. TRW, Inc., 760 F.2d 1254, 1260 (Fed. Cir. 1985). 

This court reviews for clear error the district court's determination of the factual 

inquiries underlying obviousness, while it reviews de novo the legal conclusion that a 

claim is invalid as obvious. McNeil-PPC, Inc. v. L. Perrigo Co., 337 F.3d 1362, 1368 

(Fed. Cir. 2003), cert. denied, 540 U.S. 1107 (2004). The factual determinations 

relevant to the obviousness inquiry include: (1) the scope and content of the prior art; 

(2) the differences between the claimed invention and the prior art; (3) the level of 

ordinary skill in the art; and (4) secondary considerations, if any, such as commercial 

04-1252 10
success, unexpected results, copying, long-felt but unresolved need, and the failure of

others to develop the invention. Graham v. John Deere Co., 282 U.S. 1, 17-18 (1966). 

"What the prior art teaches, whether it teaches away from the claimed invention, and 

whether it motivates a combination of teachings from different references are questions 

of fact." In re Fulton, 391 F.3d 1195, 1199-1200 (Fed. Cir. 2004). 

A finding of inequitable conduct is committed to the trial judge's discretion and is

reviewed under an abuse of discretion standard. Kingsdown Med. Consultants, Ltd. v. 

Hollister, Inc., 863 F.2d 867, 876 (Fed. Cir. 1988). "To overturn such a determination,

the appellant must establish that the ruling is based on clearly erroneous findings of fact 

or on a misapplication or misinterpretation of applicable law, or evidences a clear error

of judgment on the part of the district court." Molins PLC v. Textron, Inc., 48 F.3d 1172, 

1178 (Fed. Cir. 1995) (citing Kingsdown Medical Consultants, 863 F.2d at 876.

Findings of materiality and intent are factual findings subject to the clearly erroneous 

standard and, therefore, will not be disturbed on appeal unless this court has a definite 

and firm conviction that a mistake has been committed. Id. 

B. Claim Construction

Apotex challenges the district court's claim construction on the ground that the 

term "in a stabilizing amount" should properly be read as a claim limitation. We agree

with the district court that the term "in a stabilizing amount" simply describes the

intended result of using the weight to volume ratios recited in the claims. Accordingly,

we conclude that the district court correctly construed the disputed term of the '493

patent and correctly determined that Apotex's proposed generic version of ACULAR 

04-1252 11
would infringe all of the claims of the '493 patent. We now turn to Apotex's assertions of 

invalidity and unenforceability. 

C. Obviousness

On appeal, the critical issue is whether the use of the surfactant octoxynol 40 in 

the claimed formulations is an obvious alteration of similar formulations taught in the 

prior art. Because the district court clearly erred in its fact findings regarding 

obviousness, we remand for further consideration. 

At trial, Apotex argued that based on the prior art, a person of ordinary skill in the 

art would expect to succeed in stabilizing a formulation containing an NSAID and BAC 

with a nonionic surfactant. Contending that the formulation claimed in the '493 patent is

just such a formulation, Apotex argued that it is legally obvious. 

After conducting a bench trial, the district court made factual findings pertaining 

to the issue of obviousness. The district court noted that because the prior art at issue 

had been before the examiner during prosecution, the burden of proving the challenged 

claims obvious "is particularly high." Syntex (U.S.A.) LLC v. Apotex, Inc., No. 01-CV2214, slip op. at 40, (Dec. 29, 2003). The trial court then concluded that Apotex had 

failed to meet this heightened burden. In particular, the court held that nonobviousness 

was demonstrated by the fact that octoxynol 40 had never been used in a drug

formulation; there was no motivation to combine the prior art references, which teach 

away from the use of the surfactant octoxynol 40; that the use of octoxynol 40 in the 

claimed formulation produced unexpected results; and that Syntex had provided 

convincing evidence of the commercial success of ACULAR, the product purportedly

covered by claims of the '493 patent. Syntex, slip op. at 45. 

04-1252 12
Our review of the record reveals clear error by the district court in several of the 

grounds that led it to conclude that the invention claimed by the claims in suit would not 

have been obvious. First, the court clearly erred in finding that "[n]o pharmaceutical

formulation other than ACULAR has ever included Octoxynol 40." Second, the court

clearly erred in discussing the McCutcheon reference and in finding that each of the 

Waterbury, Gilbert, and Han references teach away from the use of octoxynol 40 in the

claimed formulations. Further, the court was under the impression that, in the absence 

of evidence that those references teach away from combination, there was a failure of

proof that there would have been any motivation by one of ordinary skill in the art to use

octoxynol 40 in the claimed formulations. In so concluding, the district court failed to 

examine the expert testimony of Dr. Mitra on the question of whether one of ordinary 

skill in the art would have deemed the invention obvious, and as a subset of the overall 

obviousness question, whether octoxynol 40 produced the unexpected results asserted 

by Syntex. In addition, we think the district court failed to appreciate that the 

prosecution history of the relevant patents, while not establishing inequitable conduct, 

casts some doubt on the final examiner's conclusion that the claimed surfactant 

produces unexpected results sufficient to overcome a prima facie case of obviousness.

Finally, we feel the district court should reconsider the significance of the commercial 

success of the patented formulation in light of our recent decision in Merck & Co. v. 

Teva Pharmaceuticals. USA, Inc., 395 F.3d 1364 (Fed. Cir. 2005). 

On remand, the district court's reconsideration of the obviousness issue should 

proceed in light of our corrections of the record. 

04-1252 13
1. Use of Octoxynol 40 in Pharmaceuticals 

The district court erred in finding that octoxynol 40 was not used in 

pharmaceuticals prior to its use in the patented invention. This finding is clearly 

contradicted by statements in the record made by Lidgate and Fu, inventors of the '493

patent. Lidgate and Fu are both named authors of a Pharmaceutical Report published 

in September of 1987, that clearly states that octoxynol 40 was a well known ingredient

in pharmaceutical products. Although Syntex contends that because this report was 

published five days after the priority date of the '493 patent it discloses no "prior uses" of 

octoxynol 40, we think it incredulous that octoxynol 40 could progress from no use, to 

"well known . . . in pharmaceutical products" in a matter of five days. Accordingly, this

report reflects that the use of octoxynol 40 in pharmaceutical compositions was known 

in the art at the relevant time, an important fact to consider in assessing the 

obviousness of the claims in suit. 

2. Teaching Away

The district court clearly erred in concluding that the Waterbury, Han, and Gilbert 

references teach away from the use of octoxynol 40 as a nonionic surfactant in

ophthalmic formulations involving NSAIDs and BAC. In addition, the district court 

incorrectly dismissed the relevance of the McCutcheon reference to the overall 

obviousness analysis. What a reference teaches or suggests must be examined in the 

context of the knowledge, skill, and reasoning ability of a skilled artisan. What a 

reference teaches a person of ordinary skill is not, as Syntex's expert appears to

believe, limited to what a reference specifically "talks about" or what is specifically

"mentioned" or “written” in the reference. Under the proper legal standard, a reference 

04-1252 14
will teach away when it suggests that the developments flowing from its disclosures are 

unlikely to produce the objective of the applicant's invention. In re Gurley, 27 F.3d 551, 

553 (Fed. Cir. 1994). A statement that a particular combination is not a preferred 

embodiment does not teach away absent clear discouragement of that combination. In 

re Fulton, 391 F.3d at 1199-1200. 

The trial court found that the Waterbury reference teaches away from the use of 

octoxynol 40 because the only formulation disclosed in the patent did not include a 

surfactant, and the only surfactant mentioned in the reference was polysorbate 80. This 

is error because a prior art reference that does not specifically refer to one element of a 

combination does not, per se, teach away. If it did, only references that anticipate could 

be used to support an obviousness analysis. However, prior art references that are 

capable of rendering an invention obvious under a section 103 analysis are not limited 

to reference that also anticipate the patent at issue. The trial court's finding that 

Waterbury teaches away is also error because at col. 13, ll. 44-48, Waterbury discloses

"ophthalmic formulations" with "active ingredient . . . stabilizer, and preservative." 

The Han reference was deemed to teach away because, although it disclosed 

the use of NSAIDs, BAC, and nonionic surfactants in ophthalmic formulations, col. 3,

Example 1, the nonionic surfactants it mentioned did not include octoxynol 40. This was 

error, because Han teaches NSAIDs, BAC, and nonionic surfactants. As with the 

Waterbury reference, the fact that octoxynol 40 was not one of the surfactants

mentioned does not, without more, support the contention that the use of octoxynol 40 

is nonobvious. 

04-1252 15
Gilbert, according to the district court, teaches away because it "states explicitly

that a stabilizer is not preferred." Syntex, slip op. at 35. This is error because although 

the preferred embodiment of Gilbert does not use a stabilizer, Gilbert discloses at col. 3, 

ll. 11-22 ophthalmic formulations that "optionally . . . contain a stabilizer." Gilbert also

discloses the combination of an NSAID, BAC, and a surfactant, and discloses a number 

of stabilizers, of which at least some, according to Apotex's expert Dr. Mitra, are 

nonionic surfactants. 

Finally, the district court discounted the significance of the McCutcheon’s

reference to the use of octoxynol 40 because although it identified octoxynol 40 as an 

emulsifier and a stabilizer, it did not describe the use of octoxynol 40 in pharmaceuticals 

and indicated that it had other uses. McCutcheon's cannot be so lightly overlooked,

because, as noted above, the record shows that octoxynol 40 was previously used in

pharmaceuticals. 

On remand, the district court should reevaluate the importance of these 

references with the understanding that they provide material disclosure and do not 

teach away. 

3. Apotex's Expert Testimony

The district court, in concluding that the cited references teach away from 

combination, further found that the evidence produced no motivation to combine. While 

the question of whether to combine McCutcheon's with other references is a live issue 

on remand, there is another focus that needs to be appreciated to fully explore the 

obviousness issue. 

04-1252 16
As the district court appreciated, the bare question of whether it would have been 

obvious to substitute one surfactant for another misplaces the proper focus on the

obviousness of the invention as a whole, and likely invites hindsight conclusion, 

forbidden by our precedent. See Gillette Co. v. S.C. Johnson & Son., Inc., 919 F.2d 

720, 724-25 (Fed. Cir. 1990). 

Apotex's expert testimony, however, cannot be lightly disregarded on the theory 

that Dr. Mitra only sought to show the obviousness of substituting octoxynol 40 for

another surfactant. Mitra's testimony may be relevant on another level, which is the 

very point on which the examiner concluded that the otherwise suspect invention was

non-obvious. Mitra's testimony has to be considered as well on the point of whether the 

results produced by use of octoxynol 40 are sufficiently unexpected as to secure the 

validity of the claims in suit. 

In this case, Apotex's expert provided his theory of why a person of skill in the art 

would not have found it unusual to seek, find, and employ octoxynol 40 in making 

formulations such as those claimed in the '493 patent. Dr. Mitra explained that the 

references at issue informed a scientist to use water-soluble, micelle-forming,9

 nonionic 

 9

 A micelle-forming compound has a hydrophilic side (water-loving) and a 

hydrophobic side (water-hating). When bound together in such a manner that they form 

a surface, the two sided nature of such compounds enable them to form little bubbles,

known as micelles. When the micelle is formed such that the hydrophilic side is on the 

outside of the bubble and the hydrophobic side is on the inside of the bubble, a 

sufficiently large micelle can encapsulate hydrophobic compounds inside the bubble. A 

micelle formed in this manner can enable otherwise insoluble compounds to dissolve in 

water. 

04-1252 17
surfactants act as stabilizers in a KT/BAC ophthalmic formulation.10 He also set forth a

scientific rationale for the informed selection of certain nonionic surfactants, and testified 

that octoxynol 40 was known and used in many products, including cosmetics.11 Dr.

Mitra also opined that knowledge of the chemical qualities of surfactants useful to the 

claimed subject matter would cause a person, "as a matter of science" to "go into 

another nonionic surfactant like octoxynols." 

To be clear, we do not require that the district court credit all (or any) of this

testimony. On remand, however, the district court should consider Apotex's claim of

obviousness in light of the applicable legal principles and unencumbered by the factual 

errors identified above. 

 10 In his Expert Report, Dr. Mitra stated that "[t]he Waterbury '151 patent

shows that the non-ionic surfactant polysorbate 80 solubilizes BAC. Therefore, one 

would expect that other non-ionic surfactants such as octoxynol 40, function as a 

surfactant." Dr. Mitra also stated that 

[b]y the time of the claimed invention on or before 1987, one of ordinary

skill in the art of ophthalmic pharmaceutical formulations would have

known that . . . . non-ionic surfactants, such as polysorbate 80, were used 

in ophthalmic formulations as a surface active agent as a solubilizer, to 

increase spreading and to reduce surface tension. Octoxynol 40 was

known as a non-ionic surfactant as shown by Grant & Hackh's Chemical 

Dictionary – Fifth Edition, McGraw-Hill, 1987 and GAF product brochures. 

11 Dr. Mitra concluded that "[t]he Waterbury '151 patent shows that the nonionic surfactant polysorbate 80 solubilizes BAC. Therefore, one would expect that other

non-ionic surfactants would work equally well and one would thus look to other

patents/publications which show that other non-ionic surfactants such as octoxynol 40, 

function as a surfactant." Dr. Mitra so concluded because the stabilizer disclosed in

Waterbury, polysorbate 80, was a water-soluble, micelle-forming, nonionic surfactant. 

Dr. Mitra opined that since octoxynol 40 is also a water-soluble, micelle-forming, 

nonionic surfactant, both compounds are capable of solubilizing the KT/BAC complex 

by encapsulation. 

04-1252 18
4. The Prosecution History

The prosecution history makes clear that the PTO initially believed a person of

ordinary skill in the art would know to use a nonionic surfactant that possessed the 

qualities of octoxynol 40 in the claimed formulation. In an Office Action dated April 28,

1989, the examiner rejected claims in the '173 parent application directed to the 

formulation containing octoxynol 40 because "it is known to use nonionic surfactants." In 

particular, the examiner stated: "The mere substitution of one nonionic [surfactant] for 

another, that is, [octoxynol 40] for the nonionic of the primary reference is not deemed a 

patentable distinction in the absence of some unobvious result." 

Syntex responded to this rejection by providing data from a test comparing the 

efficacy of octoxynol 40, polysorbate 80, and myrj 52, purportedly demonstrating 

unexpected results. The PTO examiner deemed this showing insufficient: 

It has not been shown that the claimed nonionics provide any unexpected 

results over the nonionics of the primary references. The data at page 5 

of the response shows only that "octoxynol 40" gave somewhat better 

results than some conventional nonionic surfactants. However, these data 

do not compare "octoxynol 40" to the nonionics of the primary references. 

Furthermore the concentrations of the Octoxynol 40 is [sic] greater than 

that of the other nonionic surfactants. Therefore, no conclusion can be 

drawn from said data. Also the showing is not commensurate with the 

claims which, except for claims 8, 9, and 13, recite no proportions and 

broadly set forth the NSAID, quarternary ammonium preservative and 

polyoxyethylatedoctylphenol surfactant. Finally, the data (1) do not 

specify the amount of the NSAID and (2) are not in declaration form. The 

response therefore does not overcome the rejection. 

(Emphases added). The '173 parent application was ultimately abandoned. 

The '027 continuation application was assigned to a different PTO examiner. In 

an Office Action dated February 25, 1991, the new examiner entered the same

rejection, restating, verbatim, that: "The mere substitution of one nonionic [surfactant] 

04-1252 19
for another, that is, [octoxynol 40] for the nonionic of the primary reference is not 

deemed a patentable distinction in the absence of some unobvious result." 

Syntex responded by stating that it had "shown in the prosecution of the parent to 

this application [the '173 parent application] that other nonionic surfactants, such as 

[polysorbate 80] and myrj, fail to act as stabilizers in the claimed formulations." This

statement contradicted the express finding of the initial PTO examiner that Syntex's

earlier data failed to show unexpected results. Whether the second examiner was 

aware of the earlier rejection of Syntex's claims is unknown. But the relevance of the 

inconsistency between the views of two examiners is not insignificant. 

Syntex supported its view of unexpected results with the Lidgate Declaration, 

which contained test data purporting to demonstrate the unexpected superiority of

octoxynol 40 in comparison to other octoxynols. The applicant's declaration averred 

that octoxynol 40 is satisfactory for use in the claimed formulation while octoxynols 3 

and 5 are unsatisfactory. The Lidgate Declaration, however, omitted data showing that 

octoxynol 40 did not "outperform other surfactants." The record shows that Syntex 

knew that, when compared, octoxynol 12.5 and octoxynol 40 produced test samples

that "looked equivalent at all temperatures." In addition, the '493 patent itself discussed 

the use of a shorter chain octoxynol, octoxynol 10, in the disclosed formulations. 

Although we conclude, later in this opinion, that Syntex did not commit inequitable 

conduct as charged (notably, Apotex never asserted that Syntex's arguments to the 

second examiner are suspect), we think the unvarnished view of the prosecution history

shows some weakness in the conclusion that the patentee established unexpected 

results for the claimed surfactant. 

04-1252 20
While we recognize that an issued patent is entitled to the presumption of 

validity, 35 U.S.C. § 282, and that a challenger's burden to show invalidity is more 

difficult to satisfy when prior art references have been presented to the PTO, Bausch & 

Lomb, Inc. v. Barnes-Hind/Hydrocurve, Inc., 796 F.2d 443, 447 (Fed. Cir. 1986), we 

think this case is unusual because certain key facts existed that give rise to some doubt 

as to the strength of the factual proposition that octoxynol 40 indeed produced 

unexpected results. With full respect for the general propositions that the issued patent 

is entitled to a presumption of validity, and that the examiners are expected to perform 

reasonably, see Bausch & Lomb, 796 F.2d at 447 (we assume that the patent examiner 

has some expertise in interpreting the references and some familiarity with the level of

skill in the art), on remand the district court should review the file history as part of its 

assessment of whether the invention claimed by the claims in suit are nonobvious. 

5. Commercial Success

Given the error in its fact finding, the district court should also reevaluate its

analysis of the secondary considerations. The district court appeared to rely heavily on

the commercial success of ACULAR. As discussed in Merck, the secondary

consideration of commercial success exists largely to provide a means for patentees to 

show in close cases that subject matter that appears obvious is in law unobvious

because a high degree of commercial success permits the inference that others have 

tried and failed to reach a solution. Merck, 395 F.3d at 1376. In Merck, we held that

evidence of commercial success resulted in a particularly weak inference because prior

art patents prevented others from competing to reach the solution embodied in the 

claims at issue. 395 F.3d at 1376-77. 

04-1252 21
Based on the record, we are of the view that the district court should consider the 

impact of the Merck analysis on this case. Assuming that the active ingredient in the 

formulation was previously patented, the commercial success of ACULAR may heavily

derive from subject matter that does not on the whole contribute to the patentable 

distinctiveness of these claims. In such a case, the trial court should carefully consider

whether the nexus requirement of our law is satisfied. See In re Huang, 100 F.3d 135

(Fed. Cir. 1996). 

D. Inequitable Conduct

This court has held that a breach of the duties of candor, good faith, and honesty 

when prosecuting patent applications constitutes inequitable conduct. Molins PLC, 48 

F.3d at 1178. "[I]nequitable conduct during the prosecution of a patent application 

renders the subsequently issued patent unenforceable." Life Techs., Inc. v. Clontech 

Lab., Inc., 224 F.3d 1320, 1324 (Fed. Cir. 2000). Affirmative misrepresentations of a 

material fact coupled with an intent to deceive can constitute inequitable conduct. See

Molins, 48 F.3d at 1178. "Materiality and intent to deceive are distinct factual inquiries,

and each must be shown by clear and convincing evidence." Life Techs., 224 F.3d at 

1324. Prior to March 16, 1992, this court "held that materiality for purposes of an 

inequitable conduct determination required a showing that 'a reasonable examiner

would have considered such [data] important in deciding whether to allow the patent 

04-1252 22
application.'"12 Dayco Prods., Inc. v. Total Containment, Inc., 329 F.3d 1358, 1363 (Fed. 

Cir. 2003). In making the ultimate determination of inequitable conduct, the trial court 

"must conduct a balancing test between the levels of materiality and intent, with a 

greater showing of one factor allowing a lesser showing of the other." Id.

Apotex argues that Syntex's submission of the Lidgate Declaration and the test 

results excluding data on octoxynol 12.5 constituted inequitable conduct. The district

court rejected this argument finding the omitted test results lacking in materiality and 

finding no intent to deceive the PTO. The district court concluded that test results 

concerning octoxynol 12.5 were not material because (1) the purpose of the declaration

was to show that not all octoxynols would work, not that octoxynol 40 was the only 

octoxynol that would stabilize the formulation; (2) octoxynol 5 was the closest prior art 

mentioned by the examiner; and (3) the '493 patent disclosed the potential use of

octoxynol 10 as a surfactant thereby putting the examiner on notice that octoxynol 40 

was not the only possible useful surfactant. 

The district court also concluded that Lidgate, Freyberg, and Fu, the inventors of

the '493 patent, lacked intent to deceive the PTO. The district court found the testimony

of these individuals to be credible. It also found that Apotex failed to establish by clear 

and convincing evidence that these individuals breached their duty of good faith and 

candor to the PTO. 

 12 The '027 application was filed on December 7, 1990, and the '493 patent

issued on May 5, 1992. In 1992, the rule regarding the standard for materiality of

disclosures made to the PTO during prosecution changed. Because the PTO issued its

notice of allowability regarding the Lidgate Declaration on December 3, 1991, the 

previous standard was in effect at all relevant points. Consequently, it is not necessary 

for us to address the import of this change in standard. 

04-1252 23
Credibility determinations are the type of factual determinations that are best left

to the fact finder, the trial court. Apotex points to no evidence that the district court 

failed to consider Syntex's conduct, but rather asks us to replace the court's credibility 

determinations with our own. We decline to do so and find no clear error in the district 

court's finding of no intent to deceive. 

The withheld test results showing that octoxynol 12.5 was capable of stabilizing 

the KT/BAC formulation, while material to Lidgate's statement that octoxynol 40 was

generally superior to other octoxynols in stabilizing the KT/BAC formulation, was not

sufficiently material to overcome the insufficient showing of intent. 

Given that both materiality and intent must be found and that there was no clear

error in the district court's finding of intent, the determination of no inequitable conduct is

affirmed. 

E. Infringement Analysis

Since we reverse the district court's finding that the '493 patent is

nonobvious, we do not reach the question of whether Apotex's submission of an 

ANDA for a generic version of ACULAR constitutes an act of patent infringement 

under 35 U.S.C. § 271(e). 

CONCLUSION

We affirm the district court's determination that there was no inequitable conduct 

in the prosecution of the '493 patent. We also affirm the district court's claim 

interpretation. However, because the district court committed clear error in the findings

underlying its determination of nonobviousness, we reverse the court's nonobviousness

04-1252 24
determination and remand that issue to the district court for further consideration of

obviousness. Accordingly, the judgment of the district court is 

AFFIRMED-IN-PART, REVERSED-IN-PART AND REMANDED-IN-PART. 

COSTS

Each party shall bear its own costs. 

04-1252 25
United States Court of Appeals for the Federal Circuit 

04-1252 

SYNTEX (U.S.A.) LLC and ALLERGAN, INC., 

 Plaintiffs-Appellees, 

v. 

APOTEX, INC., APOTEX CORP., 

and NOVEX PHARMA, 

 Defendants-Appellants. 

PROST, Circuit Judge, concurring. 

I agree with the majority’s well-reasoned analyses with respect to almost all of 

issues raised in this case, as well as the majority’s decision to remand this case to the 

district court for reconsideration of whether the ’493 patent is invalid for obviousness. I 

write separately only to point out my disagreement with one particular portion of the 

majority’s opinion. 

I respectfully disagree with the opinion’s focus on the proceedings at the Patent 

and Trademark Office (“PTO”) when analyzing whether the district court correctly found 

that the claimed ophthalmic formulation produced unexpected results. The majority 

analyzes the prosecution history of the ’493 patent, pointing out an “inconsistency 

between the views of two examiners” in the parent and continuation applications and a 

statement during prosecution that the majority believes “contradicted the express finding 

of the initial PTO examiner.” Ante, at 20. In light of these aspects of the prosecution 

history, the majority concludes that “this case is unusual because key facts existed that 
give rise to some doubt as to the strength of the factual proposition that octoxynol 40 

indeed produced unexpected results” and instructs the district court to “review the file 

history as part of its assessment of whether the invention claimed by the claims in suit 

are nonobvious.” Ante, at 21. Thus, the majority requires that the district court analyze 

the views of separate examiners at the PTO and review statements made by the patent 

prosecutor for possible mischaracterizations of the prosecution history. 

I view this investigation into the prosecution history as problematic in several 

respects. First, this investigation shifts the focus from the appropriate question for the 

district court to address on remand: whether the evidence shows the ’493 patent claims 

an ophthalmic formulation that produced unexpected results. Next, as the majority 

concedes, ante, at 20, Apotex never asserted that Syntex’s arguments to the second 

examiner concerning the prosecution history are suspect. Moreover, had Apotex 

asserted that these arguments were suspect, I believe the assertion would be relevant 

to the issue of inequitable conduct and not obviousness. In this regard, I don’t view the 

statement referred to by the majority as a clear mischaracterization of the prosecution 

history. And the patent prosecutor likely believed the previous data submitted to the 

first examiner did show unexpected results even if the first examiner believed the data 

did not. I also find it hard to believe that the second examiner was somehow duped into 

thinking that the first examiner agreed that the previous data showed unexpected 

results even if the statement could be understood to be misleading. 

In general, I fail to see how the conduct of a patent applicant is relevant to an 

obviousness determination. Alleged misconduct at the PTO, in terms of either 

mischaracterizations or omissions, goes to the heart of an inequitable conduct inquiry 

04-1252 2
but is simply irrelevant to an obviousness inquiry. That is not to say that if evidence 

showing that a claimed invention does not produce unexpected results was not 

disclosed to the PTO then that evidence should not be considered by the district court in 

its obviousness analysis. On the contrary, a district court should consider evidence 

relevant to an obviousness analysis even if that evidence is not disclosed to the PTO. 

In sum, I believe that, here, the district court should address the evidence in the 

record to determine whether the claimed ophthalmic formulation showed unexpected 

results. For example, the district court should review all of Lidgate’s test results, 

including test results not disclosed to the PTO such as the comparison of octoxynol 12.5 

with octoxynol 40, as well as Dr. Mitra’s reasons to discredit some of those test results. 

In my view, however, there is nothing so unusual about this case as to compel the 

district court on remand to review alleged misconduct by the patent applicant at the 

PTO. 

04-1252 3