Purdue Pharma L.P. v. Epic Pharma, LLC , 811 F.3d 1345 ( 2016 )


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  •   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
    _____________________
    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.
    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 repre-
    sented 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 plaintiff-
    appellant 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 defendant-
    appellee Amneal Pharmaceuticals, LLC. Also represented
    4                    PURDUE PHARMA L.P.   v. EPIC PHARMA, LLC
    by STEVEN D. MASLOWSKI, MATTHEW A. PEARSON, ANGELA
    VERRECCHIO, JASON WEIL; EMILY CURTIS JOHNSON, Wash-
    ington, DC; KENNETH E. CROWELL, STUART D. SENDER,
    Budd Larner, P.C., Short Hills, NJ.
    MARK DAVID SCHUMAN, Carlson, Caspers, Vanden-
    burgh, 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, Indi-
    anapolis, 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.
    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 Pharmaceuti-
    cals USA, Inc. (“Teva”), all of whom have filed Abbreviat-
    ed 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, follow-
    ing 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 collat-
    eral 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 rul-
    ings.
    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 reformu-
    lated 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 formula-
    tion of oxycodone hydrochloride. Those patents describe
    an oxycodone salt with extremely low levels of a particu-
    lar impurity, 14-hydroxycodeinone (“14-hydroxy”), which
    belongs to a class of potentially dangerous compounds
    known as alpha, beta unsaturated ketones (“ABUKs”).
    The prior art method of synthesizing oxycodone hydro-
    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 Administra-
    tion (“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 Tech-
    nologies—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.
    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 acid-
    catalyzed 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 affirm-
    ing the Board of Patent Appeals and Interferences’ de-
    termination 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 Applica-
    tion 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 refer-
    ence 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.
    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 explic-
    itly recite 8α as the source of at least a portion of the
    minimal amounts of 14-hydroxy remaining in the oxyco-
    done 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 twelve-
    hour 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 be-
    cause 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 Oxy-
    Contin® to deter abuse. Purdue initially considered,
    among other ideas, creating a tablet that would be diffi-
    cult to crush and difficult to inject, but those efforts were
    unsuccessful. In 2003, Purdue became aware of technolo-
    gy 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
    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 molecu-
    lar 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 worka-
    ble 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 strong-
    er 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 li-
    cense from Grunenthal to use the abuse deterrent tech-
    nology 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 Oxy-
    Contin® and provided that information to the FDA. On
    April 16, 2013, the FDA withdrew its approval for Origi-
    nal OxyContin® and stopped accepting ANDAs that
    proposed generic versions of it, reasoning that Reformu-
    lated 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
    10                  PURDUE PHARMA L.P.   v. EPIC PHARMA, LLC
    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 infringe-
    ment of the ’383 patent. The two Teva cases were consol-
    idated 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 three-
    week 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.
    PURDUE PHARMA L.P.   v. EPIC PHARMA, LLC                     11
    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 dis-
    closing 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). Obvi-
    ousness 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
    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 immate-
    rial in the obviousness determination. Id. at 405. Final-
    ly, 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 meritori-
    ous.
    A. Discovery of 8α
    First, Purdue contends that the court failed to proper-
    ly credit the discovery of 8α as the core of the claimed
    inventions. It relies heavily on Eibel Process Co. v. Min-
    nesota & Ontario Paper Co., 
    261 U.S. 45
    , 68 (1923), for
    the proposition that “where an inventor discovers a non-
    2   All of the asserted claims are product claims. The
    asserted claims of the ’072 patent are directed to “an
    oxycodone hydrochloride active pharmaceutical ingredi-
    ent” 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.
    PURDUE PHARMA L.P.   v. EPIC PHARMA, LLC               13
    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 gener-
    ally 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 paper-
    making 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
    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 hydro-
    genation step or under what conditions to run the hydro-
    genation 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 low-
    ABUK 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 prod-
    uct, 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 puri-
    fied 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 hydro-
    genation to remove the excess 14-hydroxy in the oxyco-
    done API. One need not know that the 14-hydroxy was
    derived from 8α as opposed to 8β to answer that question.
    PURDUE PHARMA L.P.   v. EPIC PHARMA, LLC                   15
    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 limi-
    tation, 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 hy-
    drochloride active pharmaceutical ingredient hav-
    ing 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
    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 struc-
    tural limitation.
    We also conclude that, because “derived from 8α[]” is a
    process limitation, the district court did not err in disre-
    garding 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 . . . long-
    standing 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 im-
    parts ‘structural and functional differences’ distinguishing
    the claimed product from the prior art, then those differ-
    ences ‘are relevant as evidence of no anticipation’ alt-
    hough 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
    PURDUE PHARMA L.P.   v. EPIC PHARMA, LLC                17
    not err in disregarding the process limitation in its obvi-
    ousness 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 low-
    ABUK 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 be-
    cause it could get oxycodone API at a lower cost from its
    subsidiary than it could from an unaffiliated manufactur-
    er during times of high demand. Purdue does not persua-
    sively 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 low-
    ABUK 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 regulato-
    ry requirement in 2003—less than a year before Purdue
    18                 PURDUE PHARMA L.P.   v. EPIC PHARMA, LLC
    commercialized its low-ABUK product—the need for low-
    ABUK 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 cred-
    ited Purdue and Rhodes with the discovery of 8α and
    contends that such recognition shows praise from compet-
    itors. 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 oxyco-
    done, but provides no support whatsoever for that argu-
    ment. 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,
    PURDUE PHARMA L.P.   v. EPIC PHARMA, LLC                19
    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 hot-
    melt extrusion of high molecular weight PEO to create a
    controlled-release dosage form for pharmaceuticals. The
    district court found that McGinity disclosed opioid formu-
    lations 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 conclud-
    ed 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 aux-
    iliary substances (B),
    iii) at least 60% by weight of polyalkylene
    oxide (C) having a molecular weight of 1–
    15 million according to rheological meas-
    urements, 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 ingredi-
    ent with abuse potential (A) is present in a con-
    trolled release matrix of component (C).
    20                   PURDUE PHARMA L.P.   v. EPIC PHARMA, LLC
    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 com-
    pounds to be used in its formulations, including “analge-
    sics 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, McGin-
    ity 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 opi-
    oids 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 express-
    ly contradicts this testimony, as it shows that there were,
    in fact, three analgesics on the market in a sustained-
    PURDUE PHARMA L.P.   v. EPIC PHARMA, LLC                21
    Grunenthal next argues that McGinity does not in-
    herently 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 per-
    formed in preparation for this litigation. Muzzio
    thermoformed thousands of tablets according to
    the McGinity Application disclosures. He used a
    variety of chemical compositions, extruder tem-
    peratures, 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 opi-
    oids. 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 ingre-
    dient, 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.
    22                  PURDUE PHARMA L.P.   v. EPIC PHARMA, LLC
    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 Appli-
    cation 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 con-
    vincingly 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 “Muz-
    zio has supplemented his own credibility with abundant
    documentary support in the form of raw data, photo-
    graphs, and force curves” and concluded that Grunen-
    thal’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. Muz-
    zio 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 relia-
    bility 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.
    PURDUE PHARMA L.P.   v. EPIC PHARMA, LLC                  23
    Grunenthal also points to specific disclosures in
    McGinity which it argues show that the McGinity formu-
    lations 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.
    24                  PURDUE PHARMA L.P.   v. EPIC PHARMA, LLC
    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 ingredi-
    ent 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 per-
    form any testing to confirm that the tablets he made
    according to the McGinity disclosures were controlled-
    release formulations. Grunenthal contends that without
    this testing, “there is no clear proof that Teva actually
    carried out the same process—and made the same tab-
    lets—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 con-
    trolled-release testing because McGinity clearly discloses
    PEO formulations with controlled-release properties. For
    example, in the “Field of the Invention” section, McGinity
    PURDUE PHARMA L.P.   v. EPIC PHARMA, LLC                25
    says, “The invention relates more specifically to formula-
    tions 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 limi-
    tation was disclosed in McGinity.
    B. Combination of McGinity Disclosures
    Finally, Grunenthal argues that the district court
    erred by using distinct sections of McGinity and reassem-
    bling 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 exam-
    ple, Grunenthal points out that the court selected only
    “analgesics” from the long list of pharmaceutical catego-
    ries 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 anticipa-
    tion.
    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 embodi-
    ment, McGinity says:
    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 repro-
    duced above. Thus, the district court did not impermissi-
    bly 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 determina-
    tion 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 correct-
    ness 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 preclud-
    ed 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
    PURDUE PHARMA L.P.   v. EPIC PHARMA, LLC                 27
    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 dis-
    missal of the Epic, Mylan, and Amneal actions.
    AFFIRMED