Document ID: s3://data.kl3m.ai/documents/govinfo/USCOURTS/USCOURTS-ca13-14-01307/USCOURTS-ca13-14-01307-0/pdf.json

Parties Involved:
Amneal Pharmaceuticals, LLC
Appellee
Grunenthal Gmbh
Appellant
Noramco, Inc.
Not party
P.F. Laboratories, Inc.
Not party
Purdue Pharma L.P.
Not party
Purdue Pharmaceuticals L.p.
Not party
Rhodes Technologies
Not party

Document Text:

United States Court of Appeals 

for the Federal Circuit ______________________ 

PURDUE PHARMA L.P., THE P.F. 

LABORATORIES, INC., PURDUE 

PHARMACEUTICALS L.P., RHODES 

TECHNOLOGIES,

Plaintiffs-Appellants

v.

EPIC PHARMA, LLC,

Defendant

______________________ 

2014-1294

______________________ 

Appeal from the United States District Court for the 

Southern District of New York in No. 1:13-cv-00683-SHS, 

Senior Judge Sidney H. Stein.

---------------------------------------------------------------------

PURDUE PHARMA L.P., THE P.F. 

LABORATORIES, INC., PURDUE 

PHARMACEUTICALS L.P., RHODES 

TECHNOLOGIES,

Plaintiffs-Appellants

v.

MYLAN PHARMACEUTICALS INC., MYLAN INC.,

Defendants-Appellees

_____________________ 

Case: 14-1307 Document: 10-2 Page: 1 Filed: 02/01/2016
2 PURDUE PHARMA L.P. v. EPIC PHARMA, LLC

2014-1296

______________________ 

Appeal from the United States District Court for the

Southern District of New York in No. 1:12-cv-02959-SHS, 

Senior Judge Sidney H. Stein.

---------------------------------------------------------------------

PURDUE PHARMA L.P., THE P.F. 

LABORATORIES, INC., PURDUE 

PHARMACEUTICALS L.P., RHODES 

TECHNOLOGIES, GRUNENTHAL GMBH,

Plaintiffs-Appellants

v.

AMNEAL PHARMACEUTICALS, LLC,

Defendant-Appellee

______________________ 

2014-1306, -1307

______________________ 

Appeals from the United States District Court for the 

Southern District of New York in No. 1:11-cv-08153-SHS, 

Senior Judge Sidney H. Stein.

---------------------------------------------------------------------

GRUNENTHAL GMBH, PURDUE PHARMA L.P., 

THE P.F. LABORATORIES, INC., PURDUE 

PHARMACEUTICALS L.P., RHODES 

TECHNOLOGIES,

Plaintiffs-Appellants

v.

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PURDUE PHARMA L.P. v. EPIC PHARMA, LLC 3

TEVA PHARMACEUTICALS USA, INC.,

Defendant-Appellee

______________________ 

2014-1311, -1312, -1313, -1314

______________________ 

Appeals from the United States District Court for the 

Southern District of New York in Nos. 1:11-cv-02037-

SHS, 1:12-cv-05083-SHS, Senior Judge Sidney H. Stein.

______________________ 

Decided: February 1, 2016

______________________ 

GREGORY A. CASTANIAS, Jones Day, Washington, DC, 

argued for all plaintiffs-appellants. Plaintiffs-appellants 

Purdue Pharma L.P., The P.F. Laboratories, Inc., Purdue 

Pharmaceuticals L.P., Rhodes Technologies also represented by JENNIFER LORAINE SWIZE; JOHN JOSEPH 

NORMILE, JR., New York, NY; ROBERT J. GOLDMAN, Ropes 

& Gray LLP, East Palo Alto, CA; SONA DE, CHRISTOPHER 

J. HARNETT, New York, NY.

BASIL J. LEWRIS, Finnegan, Henderson, Farabow, 

Garrett & Dunner, LLP, Washington, DC, for plaintiffappellant Grunenthal GmbH. Also represented by 

JENNIFER HOWE ROSCETTI, ERIN MCGEEHAN SOMMERS;

CHARLES E. LIPSEY, Reston, VA.

WILLIAM A. RAKOCZY, Rakoczy Molino Mazzochi Siwik 

LLP, Chicago, IL, argued for defendants-appellees Mylan

Pharmaceuticals Inc., Mylan Inc. Also represented by 

AMY D. BRODY, ERIC R. HUNT, NATASHA L. WHITE. 

BARBARA MULLIN, Akin, Gump, Strauss, Hauer & 

Feld, LLP, Philadelphia, PA, argued for defendantappellee Amneal Pharmaceuticals, LLC. Also represented 

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4 PURDUE PHARMA L.P. v. EPIC PHARMA, LLC

by STEVEN D. MASLOWSKI, MATTHEW A. PEARSON, ANGELA 

VERRECCHIO, JASON WEIL; EMILY CURTIS JOHNSON, Washington, DC; KENNETH E. CROWELL, STUART D. SENDER, 

Budd Larner, P.C., Short Hills, NJ.

MARK DAVID SCHUMAN, Carlson, Caspers, Vandenburgh, Lindquist & Schuman, P.A., Minneapolis, MN, 

argued for defendant-appellee Teva Pharmaceuticals 

USA, Inc. Also represented by M. JEFFER ALI, JENNELL 

CHRISTINE BILEK, ALEXANDRA JANE OLSON, CHRISTOPHER 

A. PINAHS, SARAH STENSLAND, TODD S. WERNER. 

DONALD E. KNEBEL, Barnes & Thornburg LLP, Indianapolis, IN, for amici curiae Donald E. Knebel, Mark 

David Janis. Also represented by MARK DAVID JANIS, 

Indiana University Maurer School of Law, Bloomington, 

IN.

BENJAMIN CONRAD BLOCK, Covington & Burling LLP, 

Washington, DC, for amicus curiae Center for Lawful 

Access and Abuse Deterrence.

______________________ 

Before PROST, Chief Judge, REYNA, Circuit Judge, and 

STARK, Chief District Judge.

∗

PROST, Chief Judge. 

This appeal arises from consolidated Hatch-Waxman 

proceedings involving the reformulated version of the pain 

reliever OxyContin®. The Appellants, Purdue Pharma 

L.P., The P.F. Laboratories, Inc., Purdue Pharmaceuticals 

L.P., and Rhodes Technologies (collectively, “Purdue”) and 

Grunenthal GmbH (“Grunenthal”) asserted a number of 

claims from multiple different patents against the Appel-

∗ Honorable Leonard P. Stark, Chief District Judge, 

United States District Court for the District of Delaware, 

sitting by designation.

 

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PURDUE PHARMA L.P. v. EPIC PHARMA, LLC 5

lees, Amneal Pharmaceuticals, LLC (“Amneal”), Epic 

Pharma, LLC (“Epic”), Mylan Pharmaceuticals Inc. and 

Mylan Inc. (collectively, “Mylan”), and Teva Pharmaceuticals USA, Inc. (“Teva”), all of whom have filed Abbreviated New Drug Applications (“ANDAs”) seeking to sell 

generic versions of OxyContin®. The United States 

District Court for the Southern District of New York held 

a three-week bench trial in the case against Teva, following which it held all of the asserted patent claims invalid. 

In re OxyContin Antitrust Litig., 994 F. Supp. 2d 367, 377 

(S.D.N.Y. 2014) (“District Court Decision”). The court 

then entered orders of dismissal in the three remaining 

cases against Amneal, Epic, and Mylan based on collateral estoppel. Purdue and Grunenthal appeal the final 

judgment in the Teva action, and Purdue also appeals the 

orders of dismissal in the three other cases. For the 

reasons stated below, we affirm the district court’s rulings. 

BACKGROUND

Oxycodone hydrochloride—the active pharmaceutical 

ingredient (“API”) in OxyContin®—is an opioid analgesic 

used to treat moderate to severe pain. This consolidated 

appeal concerns four patents associated with the reformulated version of OxyContin®: U.S. Patent No. 7,674,799 

(“’799 patent”), U.S. Patent No. 7,674,800 (“’800 patent”),

U.S. Patent No. 7,683,072 (“’072 patent”) (collectively, 

“the low-ABUK patents”), and U.S. Patent No. 8,114,383 

patent (“’383 patent”). 

I. The Low-ABUK Patents

The low-ABUK patents recite an improved formulation of oxycodone hydrochloride. Those patents describe 

an oxycodone salt with extremely low levels of a particular impurity, 14-hydroxycodeinone (“14-hydroxy”), which 

belongs to a class of potentially dangerous compounds 

known as alpha, beta unsaturated ketones (“ABUKs”). 

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6 PURDUE PHARMA L.P. v. EPIC PHARMA, LLC

chloride involved three steps: first, thebaine, a derivative 

of the opium poppy, was oxidized to form 14-hydroxy; 

second, the 14-hydroxy was converted to oxycodone free 

base through hydrogenation; and third, the oxycodone 

free base was reacted with hydrochloric acid to form 

oxycodone hydrochloride. The end product created by 

that process, however, contained high levels of 14-

hydroxy, on the order of 1500 parts per million (“ppm”). 

In January 2004, the U.S. Food and Drug Administration (“FDA”) became concerned that 14-hydroxy was 

potentially toxic and thus mandated that oxycodone 

hydrochloride manufacturers either provide evidence that 

the 14-hydroxy levels in their formulations were safe or 

reduce the amount of 14-hydroxy to less than 10 ppm. 

Even before the FDA’s mandate, however, Rhodes Technologies—a subsidiary of Purdue—had begun researching 

methods to reduce 14-hydroxy levels in its oxycodone API. 

The scientists initially hypothesized that the 14-hydroxy 

present in the final salt was leftover 14-hydroxy that had 

not been hydrogenated in the second step. Thus, they 

extended the hydrogenation reaction to completion, 

confirming that every molecule of 14-hydroxy converted to 

oxycodone free base at step two. But the scientists found 

that after step three—transforming the oxycodone free 

base into oxycodone hydrochloride—the 14-hydroxy had 

returned. 

The scientists thus shifted their focus to step three. It 

was well known in the art that an impurity, 8,14–

dihydroxy–7,8–dihydrocodeinone (“8,14-dihydroxy”) was 

produced as a byproduct of the oxidation of thebaine (step 

one). More specifically, it was known that a particular 

isomer of 8,14-dihydroxy was formed: 8β, 14–dihydroxy–

7,8–dihydrocodeinone (“8β”). Scientists did not know with 

certainty, however, whether 8α, 14–dihydroxy–7,8–

dihydrocodeinone (“8α”)—a diastereomer of 8β—was also 

produced during the oxidation step. Purdue scientists 

had previously noted the potential existence of 8α, but no 

scientific literature discussed that particular isomer. 

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PURDUE PHARMA L.P. v. EPIC PHARMA, LLC 7

Through experimentation, the scientists determined that 

8α was indeed being produced at step one and, in fact, 

was transforming into 14-hydroxy during the acidcatalyzed dehydration at step three. To remove the 14-

hydroxy from the oxycodone API, the scientists added 

another hydrogenation step at the end of step three to 

convert the remaining 14-hydroxy into oxycodone free 

base. By June 2003, Rhodes’s laboratory could routinely 

produce oxycodone API with 14-hydroxy levels less than 

10 ppm using the double-hydrogenation process. Purdue 

and Rhodes thus sought approval from the FDA and 

patent protection for their low-ABUK oxycodone product. 

The low-ABUK patents continue from application No. 

11/391,897, known as the “Chapman Application.” The 

claims of the Chapman Application have previously been 

before us; we authored a non-precedential decision affirming the Board of Patent Appeals and Interferences’ determination that the Chapman claims were obvious. 

Chapman v. Casner, 315 F. App’x 294, 295 (Fed. Cir. 

2009) (Rader, CJ., dissenting). In that case, the Board 

declared an interference between the Chapman Application and U.S. Patent No. 7,153,966 (“Casner”). The 

relevant claims in the Chapman Application related to a 

method for making oxycodone API using a hydrogenation 

step to remove 14-hydroxy, but they did not require that 

some of the remaining 14-hydroxy be derived from the 8α 

isomer. Id. The Board compared Chapman’s claims to 

the prior art and concluded that they were obvious. 

Chapman appealed directly to us, and we agreed with the 

Board. We reasoned that, because the claims did not 

specify the source of the 14-hydroxy, any prior art reference that disclosed conditions under which either 8α or 8β 

converted to 14-hydroxy would render the claim obvious. 

Id. at 297. We further noted that the prior art references 

did just that—they disclosed the conversion of 8β to 14-

hydroxy under certain conditions. Id. Thus we affirmed 

the Board’s decision to reject the Chapman claims as 

obvious. Id. at 297–98.

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8 PURDUE PHARMA L.P. v. EPIC PHARMA, LLC

Purdue eventually amended the Chapman claims to 

include the claims now on appeal. Unlike the claims in 

the Chapman Application, the claims at issue here are 

product claims instead of process claims, and they explicitly recite 8α as the source of at least a portion of the 

minimal amounts of 14-hydroxy remaining in the oxycodone API. In 2010, the U.S. Patent and Trademark Office 

allowed the claims and issued the low-ABUK patents. 

II. The ’383 Patent

The ’383 patent covers abuse-resistant formulations. 

Original OxyContin® was a popular opioid analgesic

which delivered a large dose of oxycodone over a twelvehour period. In the early 2000s, however, reports of 

widespread abuse of Original OxyContin® emerged, and 

the problem began to garner significant public attention. 

Original OxyContin® was susceptible to tampering because abusers could crush the tablets easily into powder, 

which could then be swallowed, snorted, or injected for an 

instant opioid “high.” In 2001, Purdue and the FDA

changed the label of Original OxyContin® to warn doctors 

about the potential for abusers to tamper with the dosage 

form. 

Purdue thus investigated ways to reformulate OxyContin® to deter abuse. Purdue initially considered, 

among other ideas, creating a tablet that would be difficult to crush and difficult to inject, but those efforts were 

unsuccessful. In 2003, Purdue became aware of technology developed by Grunenthal that made tablets extremely 

hard (in order to prevent crushing) and formed a gel upon 

dissolution in water (in order to prevent injecting). 

Grunenthal first began to research abuse resistant 

properties for its opioid product, tapentadol. In October 

2002, Johnson & Johnson proposed a joint venture with 

Grunenthal, using Johnson & Johnson’s osmotically 

controlled-release oral delivery system (“OROS”) to deter 

abuse. The OROS technology consists of a tablet with an

outer shell that limits the flow of the API from an inner 

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PURDUE PHARMA L.P. v. EPIC PHARMA, LLC 9

core through the use of a “push compartment” in the 

tablet. The hard outer shell is composed of high molecular weight polyethylene oxide (“PEO”), and the “push 

compartment” expands to force the API through a hole in 

the outer shell. But the tablet could still be easily 

crushed with a mortar and pestle, so it was not a workable solution. Dr. Johannes Bartholomaeus, who was the 

head of pharmaceutical development for Grunenthal at 

the time, tried to strengthen tapentadol’s dosage form by 

making the entire tablet, instead of just the outer shell, 

resistant to crushing. Dr. Bartholomaeus thus designed a 

formulation that contained a matrix of API and PEO 

throughout the tablet. Moreover, Dr. Bartholomaeus’s 

experimentation with PEO demonstrated that using both 

heat and pressure to form the tablet resulted in a stronger solid that resisted breaking by a hammer or by a 

mortar and pestle, and withstood a breaking strength test 

that exerted 500 N of force. 

After a series of negotiations, Purdue obtained a license from Grunenthal to use the abuse deterrent technology of the ’383 patent in its Reformulated OxyContin®

product. Purdue submitted a New Drug Application to 

the FDA in November 2007, proposing a Reformulated 

OxyContin®, which the FDA approved in April 2010. By 

July 2012, Purdue noted reductions in the abuse of OxyContin® and provided that information to the FDA. On 

April 16, 2013, the FDA withdrew its approval for Original OxyContin® and stopped accepting ANDAs that 

proposed generic versions of it, reasoning that Reformulated OxyContin® was available to provide the same 

benefits with lower risks of abuse and misuse. On the 

same day, the FDA approved a new label that allowed 

Purdue to market Reformulated OxyContin® on the basis 

of its abuse deterrent properties.

III. Procedural History

In March 2011, Purdue sued Teva for infringement of

the low-ABUK patents in response to Teva’s filing of an 

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ANDA seeking FDA approval to market generic versions 

of Reformulated OxyContin®. Between November 2011 

and January 2013, Purdue filed similar lawsuits against 

Epic, Mylan, and Amneal. In addition, in June 2012, 

Grunenthal and Purdue jointly sued Teva for infringement of the ’383 patent. The two Teva cases were consolidated and joined with the Epic, Mylan, and Amneal 

cases, along with six actions involving other defendants, 

in multi-district litigation for pretrial purposes. 

In September 2013, the district court held a threeweek bench trial in the Teva cases.1 The district court 

found that the asserted claims were infringed by Teva’s 

proposed generic product, but it also held that all of the 

claims were invalid as anticipated by or obvious over the 

prior art. District Court Decision, 994 F. Supp. 2d at 377. 

Based on that decision, the district court issued an order 

for Purdue to show cause as to why the actions against 

Epic, Mylan, and Amneal should not be dismissed under 

the doctrine of collateral estoppel. Purdue stated that it 

intended to appeal the Teva decision but it agreed that 

the district court’s decision regarding the invalidity of the 

low-ABUK patents precluded Purdue’s claims for relief 

against the other defendants. Accordingly, the district 

court dismissed the three remaining actions based on 

collateral estoppel. 

Purdue and Grunenthal appeal the final judgment in 

the Teva actions and Purdue also appeals the orders of 

dismissal in the three other cases. We have jurisdiction 

under 28 U.S.C. § 1295(a)(1).

1 Before the district court, Purdue accused Teva of 

infringing claims 3 and 19 of the ’799 patent, claims 30–

34 and 76–79 of the ’800 patent, claims 1, 4, and 5 of the 

’072 patent, and claims 1, 2, 5, 7, and 8 of the ’383 patent. 

 

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DISCUSSION

A patent is invalid for anticipation under 35 U.S.C. 

§ 102 if a single prior art reference discloses each and 

every limitation of the claimed invention. Schering Corp. 

v. Geneva Pharm., 339 F.3d 1373, 1377 (Fed. Cir. 2003). 

A single prior art reference may anticipate without disclosing a feature of the claimed invention if such feature 

is necessarily present, or inherent, in that reference. Id.

Anticipation is a question of fact, which we review for 

clear error. Atlas Powder Co. v. Ireco, Inc., 190 F.3d 1342, 

1346 (Fed. Cir. 1999). 

A patent is invalid for obviousness “if the differences 

between the subject matter sought to be patented and the 

prior art are such that the subject matter as a whole 

would have been obvious at the time the invention was 

made to a person having ordinary skill in the art to which 

said subject matter pertains.” 35 U.S.C. § 103(a). Obviousness is a legal conclusion based on underlying facts. 

Graham v. John Deere Co., 383 U.S. 1, 17 (1966). We 

review the underlying findings of fact for clear error, and 

we review de novo the court’s ultimate legal conclusion of 

whether the claimed invention would have been obvious. 

Novo Nordisk A/S v. Caraco Pharm. Labs., Ltd., 719 F.3d 

1346, 1354 (Fed. Cir. 2013). Underlying factual inquiries 

include (i) the scope and content of the prior art; (ii) the 

differences between the prior art and the claims at issue; 

(iii) the level of ordinary skill in the field of the invention; 

and (iv) relevant secondary considerations. KSR Int’l Co. 

v. Teleflex, Inc., 550 U.S. 398, 406 (2007); Graham, 383 

U.S. at 17–18.

I. Invalidity of the Low-ABUK Patents

Purdue challenges the district court’s conclusion that 

the asserted claims of the low-ABUK patents are invalid 

as obvious. Those claims recite an oxycodone API product 

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12 PURDUE PHARMA L.P. v. EPIC PHARMA, LLC

with low ABUK levels.2 The district court found that the 

prior art taught that oxidation of thebaine produced 14-

hydroxy and that it was well known in the art that 14-

hydroxy could be removed using hydrogenation. District 

Court Decision, 994 F. Supp. 2d at 395–96. The court 

further determined that the discovery of 8α was not 

necessary to the claimed invention: a skilled artisan 

would recognize that hydrogenation could be used to 

remove the remaining 14-hydroxy, regardless of the

source of the 14-hydroxy. Id. at 405–06. Moreover, the 

court concluded that the claim limitation requiring that 

the remaining 14-hydroxy is at least in part “derived from 

8α[]” is a product-by-process limitation and thus immaterial in the obviousness determination. Id. at 405. Finally, the district court found that the secondary 

considerations did not demonstrate nonobviousness. Id.

at 407. Purdue alleges clear error in a number of the 

court’s findings, but none of its arguments are meritorious. 

A. Discovery of 8α

First, Purdue contends that the court failed to properly credit the discovery of 8α as the core of the claimed 

inventions. It relies heavily on Eibel Process Co. v. Minnesota & Ontario Paper Co., 261 U.S. 45, 68 (1923), for 

the proposition that “where an inventor discovers a non2 All of the asserted claims are product claims. The 

asserted claims of the ’072 patent are directed to “an 

oxycodone hydrochloride active pharmaceutical ingredient” with low ABUK levels, see, e.g., ’072 patent col. 34 ll. 

57–60, while the asserted claims of the ’799 patent are 

directed to an “oral dosage form” of low-ABUK oxycodone 

hydrochloride, see, e.g., ’799 patent col. 35 ll. 8–15. The 

asserted claims of the ’800 patent are product-by-process 

claims; they are directed to “[o]xycodone salt prepared 

according to [a] process” that yields low ABUK levels. 

See, e.g., ’800 patent col. 35 ll. 49–50.

 

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obvious source of a problem and then applies a remedy in 

response, the invention is nonobvious and worthy of a 

patent—even if the remedy, standing alone, would generally appear to be known in the art.” Purdue Br. 40. In 

Eibel Process, the invention was a machine that could 

make quality paper at high speeds. 261 U.S. at 54. At 

the time, paper-making machines could not operate at 

high speeds without producing wrinkled paper. Id. Eibel 

discovered that the unequal speeds of paper stock and a 

wire in the machine produced the wrinkled paper. Thus, 

he made a minor modification in the existing papermaking machines: he increased the pitch (angle) of the 

wire so that, through gravity, the paper stock would 

travel at substantially the same speed as the wire, and 

the paper would not wrinkle. Id. at 57–58, 64–65. The 

Supreme Court upheld the validity of Eibel’s patent, 

reasoning that the discovery of the problem—unequal 

speeds of paper stock and the wire—was nonobvious, and 

thus the solution was as well. Id. at 68. Purdue contends 

that, similarly here, the discovery of the source of 14-

hydroxy was not obvious, so the solution of hydrogenating 

the oxycodone salt must also be nonobvious. 

Purdue’s reliance on Eibel Process is misplaced. Even 

if determining the source of 14-hydroxy in the end product 

was not obvious, that problem did not need to be solved to 

arrive at the claimed invention; thus, Eibel Process does 

not apply. As discussed above, the claimed invention in 

Eibel Process was a machine that remedied the problem of 

wrinkled paper at high-speed printing. But, here, Purdue 

did not claim the remedy of the problem of remaining 14-

hydroxy in the oxycodone API—performing a second 

hydrogenation step. Instead, it claimed the end product—

an oxycodone API with low ABUK levels. And, as the 

district court found, identification of the source of the 

remaining 14-hydroxy as being 8α had no effect on the 

structure or nature of the low-ABUK oxycodone product. 

Because “[o]ne molecule of 14-hydroxy is the same as the 

next, whether derived from 8α or 8β,” knowledge of 8α 

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14 PURDUE PHARMA L.P. v. EPIC PHARMA, LLC

“did not make hydrogenation more or less effective as a 

technique for converting 14-hydroxy to oxycodone.” 

District Court Decision, 994 F. Supp. 2d at 405. 

Purdue also argues that, without knowing that the 

14-hydroxy was derived from 8α, a person of ordinary skill 

in the art would not know when to conduct the hydrogenation step or under what conditions to run the hydrogenation to create low-ABUK oxycodone. Purdue notes 

that the prior art references were directed to lowering 14-

hydroxy levels in the oxycodone free base, not the API or 

salt. For example, U.S. Patent No. 6,177,567 (“Chiu 

reference”) disclosed a method for preparing low-ABUK 

free base, but it did not teach how to convert the lowABUK free base into low-ABUK salt. In fact, as Purdue 

and the district court noted, Chiu completed his method 

by adding acetic acid to the free base. In so doing, Chiu 

likely converted the latent 8α into 14-hydroxy in the final 

product because 8α reacts with the acid to form 14-

hydroxy. But, again, Purdue claimed the end product; it 

did not claim a particular method for creating that product, such as the use of hydrogenation after the salting 

step. In fact, Teva’s generic product would not infringe if 

that were the case because the Teva product is not made 

by hydrogenating the salt—instead the free base is purified through two hydrogenation cycles and then is treated 

with acid to create the oxycodone salt. Similarly, nothing 

in the asserted patents indicates that the hydrogenation 

process to remove 14-hydroxy derived from 8α must be 

conducted under different conditions from the process 

used to remove 14-hydroxy that is derived from 8β. The 

issue again comes down to whether it would be obvious to 

a person having ordinary skill in the art to use hydrogenation to remove the excess 14-hydroxy in the oxycodone API. One need not know that the 14-hydroxy was 

derived from 8α as opposed to 8β to answer that question. 

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B. “Derived from 8α[]” Limitation

Purdue next argues that, because the asserted claims 

require that the remaining 14-hydroxy in the oxycodone 

API is derived from 8α and because 8α was not previously 

known in the art as being the source of 14-hydroxy, the 

claims must be nonobvious. Indeed, Purdue points out 

that the reason it added that limitation was because of 

our decision in Chapman where we said the claims were 

obvious because the claims did not differentiate between 

the 8α and 8β. 315 F. App’x at 297. The district court 

rejected that argument because it found that the “derived 

from 8α[]” limitation was a process limitation and thus 

immaterial to the obviousness analysis. 

Purdue says, first, the limitation is not a process limitation, and, second, even if it is, it should not be wholly 

disregarded. Again, Purdue’s arguments fail. 

The relevant claim language provides:

An oral dosage form comprising . . . oxycodone hydrochloride active pharmaceutical ingredient having less than 25 ppm 14-hydroxy[], wherein at 

least a portion of the 14-hydroxy[] is derived from 

8α[] during conversion of oxycodone free base to 

oxycodone hydrochloride[.] 

See, e.g., ’799 patent col. 34 l. 65 to col. 35 l. 4 (emphasis 

added). We agree with the district court that “derived 

from 8α[]” does not describe the structure of 14-hydroxy

and thus is a process limitation. The patent specification 

describes methods for detecting and removing 14-hydroxy 

without regard to the source. For example, the written 

description defines 8,14-dihydroxy as 8α, 8β, or a mixture 

of the two and does not indicate any difference in the 

resulting 14-hydrodxy depending on the particular isomer 

from which it is derived. More specifically, there is no 

suggestion in the patents that the hydrogenation process 

changes depending on whether the 14-hydroxy is created 

by 8α or 8β. Indeed, even Purdue’s expert testified that 

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16 PURDUE PHARMA L.P. v. EPIC PHARMA, LLC

“[t]he structure of the 14-hydroxy that is generated from 

8α is the same structure that is generated from 8β.” J.A. 

4428. Because the source of the 14-hydroxy has no effect 

on its structure or its removal through hydrogenation, the 

limitation that it be “derived from 8α[]” cannot be a structural limitation. 

We also conclude that, because “derived from 8α[]” is a

process limitation, the district court did not err in disregarding the limitation in its obviousness analysis. We 

have clearly stated that “‘[i]n determining validity of a 

product-by-process claim, the focus is on the product and 

not the process of making it.’” Greenliant Sys., Inc. v. 

Xicor LLC, 692 F.3d 1261, 1268 (Fed. Cir. 2012) (quoting 

Amgen Inc. v. F. Hoffman-La Roche Ltd., 580 F.3d 1340, 

1369 (Fed. Cir. 2009)). “That is because of the . . . longstanding rule that an old product is not patentable even if 

it is made by a new process.” Id.; see also SmithKline 

Beecham Corp. v. Apotex Corp., 439 F.3d 1312, 1317 (Fed. 

Cir. 2006) (“It has long been established that one cannot 

avoid anticipation by an earlier product disclosure by 

claiming . . . the product as produced by a particular 

process.”); In re Thorpe, 777 F.2d 695, 697 (Fed. Cir. 1985) 

(“If the product in a product-by-process claim is the same 

as or obvious from a product of the prior art, the claim is 

unpatentable even though the prior product was made by 

a different process.”). 

Purdue looks to the exception we carved out in 

Amgen: “if the process by which a product is made imparts ‘structural and functional differences’ distinguishing 

the claimed product from the prior art, then those differences ‘are relevant as evidence of no anticipation’ although they ‘are not explicitly part of the claim.’” 

Greenliant, 692 F.3d at 1268 (quoting Amgen, 580 F.3d at 

1340). As previously discussed, however, the fact that the 

14-hydroxy is derived from 8α imparts no structural or 

functional differences in the low-ABUK hydrocodone API 

as compared to the prior art products. Thus, the court did 

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not err in disregarding the process limitation in its obviousness determination.

C. Secondary Considerations

Finally, Purdue contends that the court erroneously 

discounted the secondary considerations which it argues

demonstrate nonobviousness. Purdue first points to

Rhodes’s commercial success; it says that Rhodes became 

Purdue’s oxycodone API supplier by marketing the lowABUK features of its product to Purdue, which resulted in 

almost $71 million in sales in 2010. As the district court 

found, however, Rhodes was not successful at marketing 

its low-ABUK oxycodone API to any significant customer 

other than Purdue, which is its corporate affiliate. The 

district court further found that Purdue invested in 

Rhodes not because of the low-ABUK features, but because it could get oxycodone API at a lower cost from its 

subsidiary than it could from an unaffiliated manufacturer during times of high demand. Purdue does not persuasively rebut these findings on appeal. Thus, the district 

court did not clearly err in concluding that there was no 

nexus between the low-ABUK product of the patents and 

the commercial success of Purdue or Rhodes. 

Purdue next argues that the failure of others is shown 

by the experience of Teva’s oxycodone API supplier, 

Noramco, Inc. (“Noramco”). Purdue claims Noramco was 

unable to obtain low ABUK levels until 2007, years after 

Purdue discovered 8α, and only then by infringing the 

low-ABUK patents. But, as the district court found, there 

is no evidence that Noramco tried but failed to create lowABUK oxycodone API. Instead, the record showed that 

Noramco and the FDA agreed to a timetable for producing 

low-ABUK oxycodone API, that Noramco adhered to that 

timetable, and that Noramco continued to manufacture 

the higher ABUK products during that time. Purdue also 

argues that long-felt need was shown because, although 

the FDA only made low-ABUK oxycodone API a regulatory requirement in 2003—less than a year before Purdue 

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commercialized its low-ABUK product—the need for lowABUK products was present long before. That does not, 

however, change the fact that there was no pressing need 

for companies to create a low-ABUK product before the 

FDA’s mandate, as they were able to continue to sell their 

higher-ABUK products. Thus, the district court did not 

clearly err in finding that Purdue failed to prove the 

failure of others or long-felt but unaddressed need. 

Finally, Purdue points to the fact that Noramco credited Purdue and Rhodes with the discovery of 8α and 

contends that such recognition shows praise from competitors. But recognition that Rhodes discovered that 8α is a 

byproduct of thebaine oxidation does not equal praise for 

the invention—the low-ABUK oxycodone API. Purdue 

also argues that industry praise is shown because 

Noramco copied its process for creating low-ABUK oxycodone, but provides no support whatsoever for that argument. Finally, Purdue contends that the court wholly 

ignored evidence showing that Purdue and Rhodes were 

surprised over their discovery and solution. But, again, 

there was no surprise as to the patented product. Even if 

it was unexpected that thebaine oxidation would create 

8α, it was not surprising that, after the FDA mandate, 

manufacturers would create a low-ABUK oxycodone API 

or that they would do so using the known technique of 

hydrogenation. 

We find Purdue’s remaining arguments unpersuasive 

and conclude that the asserted claims of the low-ABUK 

patents are obvious. We thus affirm the district court’s 

finding of invalidity as to those claims. 

II. Invalidity of the ’383 Patent

Purdue and Grunenthal also challenge the district 

court’s conclusion that the asserted claims of the ’383 

patent are invalid as anticipated, or, in the alternative, 

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obvious.3 The district court concluded that the asserted 

claims are anticipated by WO 97/49384, known as the 

McGinity reference, which later became U.S. Patent No. 

6,488,963. District Court Decision, 994 F. Supp. 2d at 

421–26. The McGinity reference discloses the use of hotmelt extrusion of high molecular weight PEO to create a 

controlled-release dosage form for pharmaceuticals. The 

district court found that McGinity disclosed opioid formulations and that it inherently disclosed tablets with a 

breaking strength in excess of 500 N, as required by the 

asserted claims. Alternatively, the district court concluded that even if the McGinity reference did not anticipate 

the ’383 patent, “a person of ordinary skill in the art 

would have had sufficient knowledge and motivation to 

make the invention claimed by the ’383 patent.” Id. at

426. 

On appeal, Grunenthal contends that the district 

court clearly erred in finding that McGinity discloses all 

of the limitations of the asserted claims and that the 

3 Claim 1 is the only independent claim of the ’383 

patent and recites: 

A thermoformed dosage form comprising:

i) one or more active ingredients with 

abuse potential (A) selected from the 

group consisting of opiates and opioids,

ii) optionally physiologically acceptable auxiliary substances (B),

iii) at least 60% by weight of polyalkylene 

oxide (C) having a molecular weight of 1–

15 million according to rheological measurements, and

iv) optionally at least one wax (D)

wherein said dosage form has a breaking strength 

of at least 500 N and wherein the active ingredient with abuse potential (A) is present in a controlled release matrix of component (C).

 

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district court impermissibly combined discrete disclosures 

in McGinity to arrive at its anticipation determination. 

Grunenthal also asserts a number of grounds of error in 

the district court’s obviousness determination. 

A. McGinity’s Disclosure of Opioid Formulations and 

Breaking Strength

McGinity discloses a variety of therapeutic compounds to be used in its formulations, including “analgesics such as aspirin, acetaminophen, d[i]flunisal and the 

like.” J.A. 135074. Grunenthal argues that, because the 

only specifically mentioned drugs are non-opioids, McGinity does not describe formulations that contain opioids 

such as oxycodone. It invokes the canon of construction 

ejusdem generis—which provides that general terms are 

construed as referring to things of the same kind as those 

specifically mentioned—to argue that the terms “such as” 

and “and the like” should be understood as also referring 

to other non-opioids. But, as the district court found, the 

McGinity reference cannot be read so narrowly. The 

McGinity reference explicitly notes the use of its process 

with analgesics to treat pain, and the words “such as” and 

the residual clause “and the like” demonstrate that the 

application discloses a broader group of analgesics than 

just those listed. Moreover, the record showed that opioids are a major class of analgesics and that oxycodone 

was one of the most widely prescribed analgesics at the 

time. The district court also noted that the McGinity 

reference is directed to sustained-release dosage forms 

and credited expert testimony that the only analgesics on 

the market in a sustained-release form at the time were 

opioids.4 The district court’s assessment is persuasive 

and not clearly erroneous.5 

4 Grunenthal says that the record evidence expressly contradicts this testimony, as it shows that there were, 

in fact, three analgesics on the market in a sustained-

 

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Grunenthal next argues that McGinity does not inherently disclose the limitation that the dosage forms 

have a breaking strength of at least 500 N. According to 

the district court, 

The pivotal evidence [with respect to the breaking 

strength limitation] is a series of breaking 

strength tests that Dr. Fernando Muzzio performed in preparation for this litigation. Muzzio 

thermoformed thousands of tablets according to 

the McGinity Application disclosures. He used a 

variety of chemical compositions, extruder temperatures, screw speeds, and die diameters. He 

tested a vast number of the resulting tablets, and 

without exception they withstood forces greater 

than 500N. In fact, Muzzio often exerted forces in 

the thousands of Newtons and never had a tablet 

break. 

release form at the time and only two of them were opioids. But Grunenthal never made that argument before 

the district court—it did not cross-examine the expert on 

this point or otherwise take issue with the accuracy of the 

expert testimony. In any event, the fact that two of the 

three sustained-release drugs on that market at the time 

were opioids is persuasive evidence that a skilled artisan 

would understand McGinity as describing formulations 

that use opioids.

5 Grunenthal also contends that McGinity does not 

disclose the limitation that the active ingredient has 

“abuse potential.” ’383 patent col. 22 l. 3. Because we 

find that the district court did not err in concluding that 

McGinity discloses the use of an opioid as an active ingredient, and because the record clearly demonstrates that 

opioids have abuse potential, we similarly find that the 

district court did not err in concluding that McGinity 

discloses formulations where the active ingredient has 

abuse potential. 

 

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District Court Decision, 994 F. Supp. 2d at 423. The 

district court credited Dr. Muzzio’s testing and noted that, 

“[i]n contrast with [Dr. Muzzio’s] persuasive experimental 

evidence, plaintiffs have not put forward any evidence 

that any tablet produced according to the McGinity Application can ever break when a force of 500N is applied to 

the tablet.” Id. The district court thus concluded that the 

McGinity reference “inherently discloses a breaking 

strength greater than 500N, because the experimental 

results indicate unanimously, reliably, clearly, and convincingly that any tablet made according to the McGinity 

Application would exhibit this characteristic.” Id. at 424. 

Grunenthal asserts a number of grounds of error, 

many of which focus on the adequacy and reliability of Dr. 

Muzzio’s testing. For example, Grunenthal argues that 

Dr. Muzzio did not provide API release data, photographs 

after breaking strength testing, or laboratory notebooks 

for his reproductions of the McGinity disclosures. But the 

district court rejected that argument, finding that “Muzzio has supplemented his own credibility with abundant 

documentary support in the form of raw data, photographs, and force curves” and concluded that Grunenthal’s attacks “do not seriously lessen the weight the 

Court assigns to Muzzio’s vast empirical results and 

credible opinion on the inherency of a 500N breaking 

strength.” Id. Similarly, Grunenthal says that Dr. Muzzio did not perform a torque test on its reproductions, 

which would have shown if the extrusion was being 

accurately repeated. Again, however, the district court 

found that argument unpersuasive, concluding that 

“because torque is not an input or setting in the extrusion 

process, the lack of torque data does not affect the reliability of Muzzio’s process as a replication of the McGinity 

Application’s process.” Id. The district court credited Dr. 

Muzzio with having “recreated the McGinity Application’s 

process fairly, accurately, and with no material variation,” 

and Grunenthal has shown no clear error in that finding. 

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Grunenthal also points to specific disclosures in 

McGinity which it argues show that the McGinity formulations do not necessarily have the required breaking 

strength. First, it notes that McGinity discloses tablets 

that can be scored—making them easy to break in half—

or ground, which it contends is the antithesis of high 

breaking strength tablets. Next, Grunenthal argues that 

McGinity contemplates the use of heat or pressure to 

create the disclosed tablets, but notes that tablets with 

500 N breaking strength can only be formed using both

heat and pressure. Neither of those disclosures, however, 

changes the fact that every tablet made according to 

McGinity’s disclosures and tested by Dr. Muzzio had a 

breaking strength of over 500 N. And, again, Grunenthal 

has not shown clear error in the district court’s crediting 

of Dr. Muzzio’s testing results, nor has it provided any 

independent testing to rebut Dr. Muzzio’s findings.6 

6 Moreover, Grunenthal incorrectly characterizes 

the McGinity disclosures. Grunenthal relies on one 

isolated sentence to support its argument that McGinity 

contemplates the use of heat or pressure in its process: 

“[A] hot-melt extrudable polymer is one that is . . . capable 

of deformation . . . under elevated heat or pressure.” J.A. 

135076. But that sentence merely defines the type of

polymer used; it does not say that the extrusion process 

requires only heat or pressure and not both. In fact, in 

describing the actual hot-melt process, McGinity says it 

should be “conducted at an elevated temperature” and 

explains that the pharmaceutical mixture should be 

“passed through the heated area of the extruder at a 

temperature which will melt or soften the PEO.” J.A. 

135077. Indeed, Grunenthal’s own expert testified that 

hot-melt extrusion requires achieving the “melt flow” 

temperature of ninety-eight degrees Celsius for high 

molecular weight PEO. J.A. 3845–46.

 

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Grunenthal’s last two arguments relate to testing that 

Dr. Muzzio did not perform. Grunenthal notes that Dr. 

Muzzio only tested formulations with the active ingredient disclosed in McGinity, chlorpheniramine maleate 

(“CPM”), which is an antihistamine, not an opioid. Thus, 

Grunenthal says that Dr. Muzzio’s tests only proved that 

CPM formulations would have a breaking strength of 500 

N or more, not that opioid formulations, as claimed in the 

’383 patent, would have such a breaking strength. But, 

Dr. Muzzio testified that any tablet made using at least 

fifty weight percent PEO and heated above the melting 

point of PEO would have a breaking strength above 500 

N, regardless of the active ingredient used. J.A. 3462. 

The district court did not clearly err in crediting that 

testimony. 

Next, Grunenthal argues that Dr. Muzzio did not perform any testing to confirm that the tablets he made 

according to the McGinity disclosures were controlledrelease formulations. Grunenthal contends that without 

this testing, “there is no clear proof that Teva actually 

carried out the same process—and made the same tablets—disclosed in McGinity.” Grunenthal Br. 38. That is 

incorrect. As stated above, the district court credited Dr. 

Muzzio with recreating the McGinity process “fairly, 

accurately, and with no material variation.” District 

Court Decision, 994 F. Supp. 2d at 424. Grunenthal has 

not shown clear error in the district court’s finding and 

cannot do so by claiming that Dr. Muzzio did not conduct 

an additional test to confirm what the district court 

already found—that he properly replicated the McGinity 

process. Grunenthal also says that, without testing the 

controlled-release properties of the tablets, Teva cannot 

prove that the limitation requiring “a controlled release 

matrix of [the PEO]” is disclosed by McGinity. That is 

also incorrect. Teva did not need to conduct any controlled-release testing because McGinity clearly discloses 

PEO formulations with controlled-release properties. For 

example, in the “Field of the Invention” section, McGinity 

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says, “The invention relates more specifically to formulations which have been prepared by hot melt extrusion of 

mixtures containing high molecular weight PEO and a 

therapeutic compound for use in controlled-release drug 

delivery.” J.A. 135067. Thus, the district court did not 

clearly err in concluding that the controlled-release limitation was disclosed in McGinity. 

B. Combination of McGinity Disclosures

Finally, Grunenthal argues that the district court 

erred by using distinct sections of McGinity and reassembling them into an embodiment to find that all of the 

limitations were present. See Application of Arkley, 455 

F.2d 586, 587 (C.C.P.A. 1972) (noting that an anticipating 

reference “must clearly and unequivocally disclose the 

claimed compound or direct those skilled in the art to the 

compound without any need for picking, choosing, and 

combining various disclosures not directly related to each 

other by the teachings of the cited reference”). For example, Grunenthal points out that the court selected only 

“analgesics” from the long list of pharmaceutical categories that could be used as the active ingredient, and then 

further picked oxycodone, which was not even disclosed, 

to find anticipation. Moreover, Grunenthal notes that 

McGinity teaches that the amount of PEO will vary 

depending on various factors and does not consistently 

disclose formulations with at least sixty weight percent 

PEO, as required by the claims. Thus, Grunenthal argues 

that the court impermissibly chose only those examples 

that included the claimed amount of PEO to find anticipation. 

These arguments are without merit. The disclosures 

pointed to by the district court are all “directly related” 

and thus there is no impermissible picking and choosing. 

Arkley, 455 F.2d at 587. For example, in the section 

providing a detailed description of the preferred embodiment, McGinity says:

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26 PURDUE PHARMA L.P. v. EPIC PHARMA, LLC

[T]he invention provides a hot-melt extrudable 

controlled release pharmaceutical formulation 

comprising an effective amount of a therapeutic 

compound, high molecular weight [PEO] . . . , the 

[PEO]:therapeutic compound ratio being in the 

range from about 99.99:0.01 to about 80:20 % wt. 

J.A. 135802. In that single disclosure, McGinity describes 

the controlled-release formulation and the use of over 

sixty weight percent PEO. It does not specifically say 

what therapeutic compound is used, but it provides a list 

of the types of therapeutic compounds contemplated. 

That list of compounds, although in a distinct section of 

the reference, is directly related to the disclosure reproduced above. Thus, the district court did not impermissibly combine distinct disclosures in McGinity to arrive at 

the claimed invention. 

We conclude that the district court did not clearly err 

in finding that the McGinity reference discloses each and 

every limitation in the asserted claims of the ’383 patent. 

We thus affirm the district court’s anticipation determination and do not reach the question of obviousness. 

III. Collateral Estoppel

In addition to appealing the judgments of invalidity, 

Purdue also appeals the dismissal of the Epic, Mylan, and 

Amneal actions with respect to the low-ABUK patents. 

On appeal from orders of dismissal due to collateral 

estoppel, “our role is limited to reviewing the district 

court’s application of collateral estoppel, not the correctness of the [underlying] verdict[].” Pharmacia & Upjohn 

Co. v. Mylan Pharm., Inc., 170 F.3d 1373, 1380 (Fed. Cir. 

1999). Before the district court, Purdue conceded that 

collateral estoppel applied to the judgment of invalidity as 

to the low-ABUK patents in the Teva case, which precluded it from obtaining the relief sought in the remaining 

actions. Purdue also does not present any persuasive 

argument on appeal as to why collateral estoppel should 

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not apply. Thus, we affirm the district court’s dismissal of 

the remaining actions as barred by collateral estoppel. 

CONCLUSION

For the foregoing reasons, we affirm the district 

court’s invalidity determinations as to the low-ABUK 

patents and the ’383 patent and the district court’s dismissal of the Epic, Mylan, and Amneal actions. 

AFFIRMED

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