Par Pharmaceutical, Inc. v. Hospira, Inc. ( 2020 )


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  • Case: 20-1273    Document: 44    Page: 1   Filed: 11/23/2020
    NOTE: This disposition is nonprecedential.
    United States Court of Appeals
    for the Federal Circuit
    ______________________
    PAR PHARMACEUTICAL, INC., PAR STERILE
    PRODUCTS, LLC, ENDO PAR INNOVATION
    COMPANY, LLC,
    Plaintiffs-Appellees
    v.
    HOSPIRA, INC.,
    Defendant-Appellant
    ______________________
    2020-1273
    ______________________
    Appeal from the United States District Court for the
    District of Delaware in No. 1:17-cv-00944-JFB-SRF, Senior
    Judge Joseph F. Bataillon.
    ______________________
    Decided: November 23, 2020
    ______________________
    DANIEL BROWN, Latham & Watkins LLP, New York,
    NY, argued for plaintiffs-appellees. Also represented by
    JENNIFER KOH, San Diego, CA; GABRIEL BELL, Washington,
    DC.
    THOMAS J. MELORO, Willkie Farr & Gallagher LLP,
    New York, NY, argued for defendant-appellant. Also
    Case: 20-1273     Document: 44      Page: 2    Filed: 11/23/2020
    2                   PAR PHARMACEUTICAL, INC.    v. HOSPIRA, INC.
    represented by DEVON WESLEY EDWARDS, MATTHEW S.
    FREIMUTH.
    ______________________
    Before DYK, TARANTO, and STOLL, Circuit Judges.
    TARANTO, Circuit Judge.
    The plaintiffs (collectively, Par) own and have exclu-
    sive rights to U.S. Patent Nos. 9,119,876 and 9,295,657,
    which claim particular compositions containing epineph-
    rine, the active ingredient in Par’s Adrenalin® products, as
    well as methods of administering such compositions to pa-
    tients. In 2017, Hospira, Inc. filed an Abbreviated New
    Drug Application (ANDA) with the Food and Drug Admin-
    istration, seeking permission to manufacture and market a
    generic version of Par’s Adrenalin® epinephrine injection,
    1 mg/mL, product. Par sued Hospira for patent infringe-
    ment under 
    35 U.S.C. § 271
    (e), alleging that the ANDA was
    for a product, and use of a product, claimed in the ’876 and
    ’657 patents. As relevant on appeal, Hospira responded by
    disputing infringement on the ground that its ANDA prod-
    uct would not meet several limitations of the asserted
    claims. After a bench trial, the district court ruled for Par
    and against Hospira, finding that Hospira’s ANDA was for
    a product that meets the disputed claim limitations. Par
    Pharm., Inc. v. Hospira, Inc., 
    420 F. Supp. 3d 256
     (D. Del.
    2019) (Par). Hospira appeals the infringement determina-
    tion. We affirm.
    I
    A
    The ’876 and ’657 patents share a specification. The
    patents describe a “pharmaceutical composition compris-
    ing epinephrine,” which is used for “emergency treatment
    of allergic reactions.” ’876 patent, col. 2, lines 57–59. Par’s
    product, Adrenalin®, is an example of such a composition.
    
    Id.,
     col. 1, lines 30–39.        Previous formulations of
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    PAR PHARMACEUTICAL, INC.   v. HOSPIRA, INC.                 3
    epinephrine, the patent states, tended to have short shelf
    lives because epinephrine degrades by three different
    mechanisms (oxidation, racemization, and sulfonation),
    and scientists found it difficult to control degradation by
    one mechanism without exacerbating degradation by an-
    other. Par, 420 F. Supp. 3d at 262; J.A. 240–41; J.A. 530–
    38; ’876 patent, col. 1, lines 51–67. A predecessor company
    of Par eventually developed an improved formulation of
    Adrenalin® that met FDA standards for stability and qual-
    ity, and Par secured the ’876 patent on the composition in
    September 2015, then the ’657 patent on use of the compo-
    sition in March 2016. Par, 420 F. Supp. 3d at 262; J.A.
    4127–28.
    The ’876 and ’657 patents each have only one independ-
    ent claim. Claim 1 of the ’876 patent recites:
    A composition comprising:
    in the range of about 0.5 to 1.5 mg/mL
    of epinephrine and/or salts thereof,
    in the range of about 6 to 8 mg/mL of
    a tonicity regulating agent,
    in the range of about 2.8 to 3.8 mg/mL
    of a pH raising agent,
    in the range of about 0.1 to 1.1 mg/mL
    of an antioxidant,
    in the range of about 0.001 to 0.010
    mL/mL of a pH lowering agent, and
    in the range of about 0.01 to 0.4
    mg/mL of a transition metal complex-
    ing agent,
    wherein the antioxidant comprises sodium
    bisulfite and/or sodium metabisulfite.
    ’876 patent, col. 28, lines 2–14 (emphases added). Claim 1
    of the ’657 patent claims “a method of treating a condition”
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    4                   PAR PHARMACEUTICAL, INC.   v. HOSPIRA, INC.
    by “administering” a composition with the same compo-
    nents and same concentration ranges as those identified in
    claim 1 of the ’876 patent. ’657 patent, col. 28, lines 28–47.
    Although additional limitations appear in claim 1 of the
    ’657 patent and in both patents’ other asserted claims (each
    dependent on its patent’s claim 1), the only limitations at
    issue in this court appear in claim 1 of the ’876 patent—
    specifically, the limitations (emphasized above) that ad-
    dress (1) the tonicity regulating agent, (2) the transition
    metal complexing agent, and (3) the pH lowering agent.
    Tonicity is the “effective osmotic pressure equivalent of
    a solution or composition.” ’876 patent, col. 8, lines 47–49.
    For living cells to maintain their physical integrity without
    shrinking or swelling, the osmotic pressure outside the cell
    must not exert too little (hypotonic) or too much (hyper-
    tonic) tension on the cells’ walls. J.A. 542–44. A tonicity
    regulating agent ensures that fluid injected into the blood
    remains isotonic, i.e., exerts the same pressure as human
    physiological fluid on the surrounding cells. J.A. 542–45.
    A “transition metal complexing agent” reduces degra-
    dation of epinephrine through epinephrine’s binding to
    transition metals (e.g., copper and gold) in the formulation.
    Hospira identifies such transition metals as “elemental im-
    purities.” Hospira Op. Br. 18 n.6 (“Elemental impurities
    include transition metals that may be present in the com-
    position.”). Such a complexing agent can achieve that re-
    duction by binding to the transition metals, making the
    bound molecules unavailable for binding to the epineph-
    rine. J.A. 412–14. One type of transition metal complexing
    agent performing that function is a “chelating agent,”
    which is an agent that forms “two or more separate coordi-
    nate bonds” with metal ions. ’876 patent, col. 7, lines 11–
    14.
    A “pH lowering agent,” according to the parties’ agreed-
    upon claim construction, is a “[c]omponent to lower the
    composition’s pH.” J.A. 76. Claim 1 requires not only a pH
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    PAR PHARMACEUTICAL, INC.   v. HOSPIRA, INC.                 5
    lowering agent but also a pH raising agent, each within
    prescribed ranges. The patents state that “the pH raising
    agent” may include “a buffer system,” which itself “may
    comprise . . . more than one agent, such as a weak acid and
    its conjugate base,” i.e., a combination of a lowering agent
    (acid) and a raising agent (base). ’876 patent, col. 3, lines
    44–50; see also id., col. 8, lines 43–45 (“In certain embodi-
    ments, the pH lowering agent may be a portion of the buffer
    system in conjugation with a pH raising agent.”).
    B
    In June 2017, Hospira notified Par that it had submit-
    ted an ANDA to the FDA for approval to “manufacture, use,
    [sell], offer [to sell], and/or [import]” a generic version of
    Adrenalin®. J.A. 4129. On July 13, 2017, Par filed a com-
    plaint for patent infringement against Hospira in the Dis-
    trict of Delaware under 
    35 U.S.C. § 271
    (e)(2), which
    provides that it is “an act of infringement to submit” an
    ANDA if the ANDA is “for a drug claimed in a patent or the
    use of which is claimed in a patent.” Par contended that
    Hospira’s ANDA was “for” a product that comes within
    claim 1 of the ’876 patent (and other claims of the ’876 pa-
    tent dependent on claim 1) and whose use comes within
    claim 1 of the ’657 patent (and other claims of the ’657 pa-
    tent dependent on claim 1). J.A. 4033. Hospira denied that
    infringement allegation. Par, 420 F. Supp. 3d at 260, 264. 1
    During discovery, the parties submitted agreed-upon
    claim constructions, including one for the term “about,”
    which appears in all the numerical-range claim limitations
    at issue. J.A. 76. They agreed that “about” should be con-
    strued as having its “plain and ordinary meaning, i.e., ap-
    proximately.” Id. In a pretrial order, the district court
    1   Hospira also asserted invalidity, but the district
    court rejected that assertion, Par, 420 F. Supp. 3d at 279–
    80, and Hospira has not appealed that ruling.
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    6                   PAR PHARMACEUTICAL, INC.   v. HOSPIRA, INC.
    stated that “[t]he extent of the term ‘about’ must be deter-
    mined using a functional approach because ‘it is impossible
    to “capture the essence” of the claimed invention in strict
    numeric terms.’” Par Pharm., Inc. v. Hospira, Inc., No.
    1:17-cv-944, 
    2019 WL 2571165
    , at *2 (D. Del. June 21,
    2019) (quoting Cohesive Techs., Inc. v. Waters Corp., 
    543 F.3d 1351
    , 1369–71 (Fed. Cir. 2008)). The court added that
    the proper scope of the concentration range encompassed
    by “about” “requires a factual inquiry as to the purpose of
    the limitation.” 
    Id.
    We summarize the key trial evidence regarding literal
    infringement. Given our affirmance of the finding of literal
    infringement, we omit mention of the evidence regarding
    infringement under the doctrine of equivalents.
    Regarding tonicity, Par’s expert, Dr. Elder, testified at
    trial that “about 6 to 8 mg/mL of a tonicity regulating
    agent,” as construed, would be understood in light of the
    stated purpose of the tonicity regulating agent—to main-
    tain the integrity of living cells following the injection of
    epinephrine into the bloodstream. J.A. 158; see also ’876
    patent, col. 8, lines 46–53 (explaining that the tonicity reg-
    ulating agent’s purpose is to “maintain the tonicity of the
    composition in a physiological acceptable range”). He
    noted that sodium chloride is “the prefer[red] . . . tonicity
    regulating agent,” ’876 patent, col. 8, lines 58–59, and that
    Hospira’s ANDA identifies sodium chloride in its product
    as included for “isotonicity,” J.A. 1290. See J.A. 152, 158.
    He also noted that the ANDA identifies 9 mg/mL of sodium
    chloride as a component of the covered composition, J.A.
    1290, and that Hospira’s test batches contained sodium
    chloride in amounts as low as 8.55 mg/mL, See J.A. 152–
    53. Dr. Elder opined, on those facts, that Hospira’s ANDA
    product would fall within the contemplated “physiologi-
    cally acceptable” range and therefore literally infringe the
    claim limitation. J.A. 152–53, 155–58.
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    PAR PHARMACEUTICAL, INC.   v. HOSPIRA, INC.                 7
    Dr. Pinal, Hospira’s expert, did not dispute the facts
    about the role of sodium chloride or the amounts covered
    by Hospira’s ANDA. Rather, he disagreed with Dr. Elder
    about whether the amounts came within the claimed
    “about” range. He opined that a relevant artisan would un-
    derstand “about” to encompass only slight deviations from
    a specific target concentration, e.g., due to measurement
    errors, and not to embrace the amounts covered by Hos-
    pira’s ANDA. J.A. 553–56.
    Regarding the transition metal complexing agent claim
    limitation, the evidence showed that Hospira’s ANDA spec-
    ifies a particular concentration of citric acid, a known che-
    lating agent, J.A. 1290, and also states that the ANDA
    product’s “elemental impurities” (which include transition
    metals, as noted supra) satisfy the requirements of the In-
    ternational Conference on Harmonisation of Technical Re-
    quirements for Registration of Pharmaceuticals for
    Humane Use (ICH) Q3D guidelines, J.A. 1043; ICH Guide-
    lines, J.A. 2485. The referred-to ICH Q3D guidelines spec-
    ify that (to avoid the need for additional controls) elemental
    impurities in drug products be less than 30% of the speci-
    fied permitted daily exposure (PDE). J.A. 2496–97. In the
    table it presented to the FDA, Hospira represented that
    “[d]rug product testing is not required” because
    “[e]lemental impurity levels for potential elements tested
    were found to be consistently less than 30% of the . . .
    PDE.” J.A. 1043 (cleaned up). Par’s expert, Dr. Toste, ex-
    plained that using the upper limit of potential metals for
    his calculations was appropriate “[b]ecause the ANDA says
    [Hospira] could have up to that amount [of transition met-
    als] and still be able to sell [its product].” J.A. 483. Using
    the 30% figure, Dr. Toste calculated the amount of citric
    acid that would act as a transition metal complexing agent
    for that level of transition metals—an amount that comes
    within the claimed range of 0.01 to 0.4 mg/mL. J.A. 426–
    35.
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    8                   PAR PHARMACEUTICAL, INC.   v. HOSPIRA, INC.
    Hospira’s expert, Dr. Gokel, admitted that the ANDA
    product includes a specified concentration of citric acid, see
    J.A. 1290, and that citric acid has known chelating proper-
    ties, allowing it to complex with transition metals. J.A.
    741, 754–55. Dr. Gokel did not disagree with Dr. Toste’s
    calculation of the amount of citric acid serving as a transi-
    tion metal complexing agent if one used the 30% level for
    the calculation. But Dr. Gokel rejected the use of the upper
    limit of the ICH guidelines to calculate the amount of tran-
    sition metal complexing agent in the ANDA product, testi-
    fying that the proper concentration of transition metals
    should be the amounts measured in test batches of Hos-
    pira’s product. J.A. 763–65. Using the test batches, Dr.
    Gokel opined that the amount of citric acid that would
    serve as a transition metal complexing agent in the ANDA
    product would be far below the “about 0.01 to 0.4 mg/mL”
    claimed in Par’s patents. J.A. 766.
    Regarding the claim requirement of “about 0.001 to
    0.010 mL/mL of a pH lowering agent,” the trial evidence
    established that Hospira’s ANDA covered a product con-
    taining a buffer system of citric acid and its conjugate base,
    sodium citrate, which together are considered the pH rais-
    ing agent. 2 J.A. 591. And it is undisputed that citric acid,
    being an acid, itself is a pH lowering agent. See, e.g., J.A.
    406–07, 409, 693. Par’s expert, Dr. Toste, identified the
    amount of citric acid covered by Hospira’s ANDA, sub-
    tracted the amount that could serve as a complexing agent
    2   The parties’ agreed-upon claim constructions state
    that “pH raising agent” means a “[c]omponent to raise the
    composition’s pH, which may comprise a buffer system,”
    and a “buffer system” is a “[c]omponent present in a com-
    position or solution, which may provide a resistance to sig-
    nificant change in pH caused by a strong acid or base; may
    comprise a single agent or more than one agent, such as a
    weak acid and its conjugate base.” J.A. 76.
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    PAR PHARMACEUTICAL, INC.   v. HOSPIRA, INC.                 9
    with transition metals, then concluded that the remaining
    citric acid would come within the claimed range for a pH
    lowering agent—even while those same citric-acid mole-
    cules would be part of the buffer system (citric acid com-
    bined with sodium citrate) that would serve as a pH raising
    agent. J.A. 449–53.
    Dr. Pinal, testifying for Hospira, disagreed with count-
    ing the non-metal-complexing molecules of citric acid both
    as a pH lowering agent and as part of the pH raising agent.
    On that basis, he viewed only the hydrochloric acid in Hos-
    pira’s ANDA product as a pH lowering agent. J.A. 590–91.
    It is undisputed that the hydrochloric acid in the ANDA
    product is below the low end of the range stated in the pH-
    lowering-agent claim limitation. Accordingly, Dr. Pinal
    opined, that limitation is not met. Id.
    The district court resolved the foregoing issues in Par’s
    favor. First, the court determined that the sodium chloride
    permitted by Hospira’s ANDA comes within the claim lim-
    itation requiring “about 6 to 8 mg/mL” of a tonicity regulat-
    ing agent. Par, 420 F. Supp. 3d at 277–78. (The court
    added that, in the alternative, the limitation is met under
    the doctrine of equivalents. Id. at 278.) Second, the court
    determined that the ANDA covered a product having citric
    acid that would serve as a transition metal complexing
    agent in an amount that comes within the claimed-re-
    quired range. Id. Third, the court found that Hospira’s
    ANDA covered a product having citric acid that served as
    a pH lowering agent in an amount that comes within the
    claim-required range. Id. at 277.
    Hospira timely appealed. We have jurisdiction under
    
    28 U.S.C. § 1295
    (a)(1).
    II
    We review the district court’s conclusions of law de
    novo and its findings of fact for clear error. Fed. R. Civ. P.
    52(a)(6); Vanda Pharm., Inc. v. West-Ward Pharm.
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    10                 PAR PHARMACEUTICAL, INC.   v. HOSPIRA, INC.
    International Ltd., 
    887 F.3d 1117
    , 1123 (Fed. Cir. 2018).
    Infringement in this context, i.e., whether an ANDA is “for”
    a patent-claimed drug or a patent-claimed use of a drug
    under 
    35 U.S.C. § 271
    (e)(2), is an issue of fact whose reso-
    lution by the district court is reviewed for clear error.
    Vanda, 887 F.3d at 1125.
    On appeal, Hospira argues that the district court com-
    mitted clear error in finding that its ANDA product con-
    tains: (1) “about 6 to 8 mg/mL of a tonicity regulating
    agent”; (2) “about 0.01 to 0.4 mg/mL of a transition metal
    complexing agent”; and (3) “about 0.001 to 0.010 mL/mL of
    a pH lowering agent.” We reject each argument.
    A
    Hospira first argues that its ANDA product would not
    come within the claim requirement of “about 6 to 8 mg/mL
    of a tonicity regulating agent” given that its ANDA speci-
    fies a target concentration of 9 mg/mL of sodium chloride.
    Hospira Op. Br. 34–50. The parties agreed in the district
    court that the term “about” had its “[p]lain and ordinary
    meaning; i.e., approximately.” J.A. 76. Hospira did not
    propose any further narrowing construction. On appeal,
    Hospira contends that the district court, in applying the
    plain-meaning construction to the ANDA, improperly de-
    parted from this court’s decision in Cohesive Techs. v. Wa-
    ter Corp., 
    543 F.3d 1351
     (Fed. Cir. 2008), concerning an
    “about” term in a claim range. We disagree.
    “When ‘about’ is used as part of a numeric range, ‘the
    use of the word “about” avoids a strict numerical boundary
    to the specified parameter.’” Cohesive, 543 F.3d at 1368
    (citing Pall Corp. v. Micron Separations, Inc., 
    66 F.3d 1211
    ,
    1217 (Fed. Cir. 1995)). The authorized extension beyond
    the stated numbers in the range is cabined to what “a per-
    son having ordinary skill in the art . . . would reasonably
    consider ‘about . . .’ to encompass.” Monsanto Tech. LLC v.
    E.I. DuPont de Nemours & Co., 
    878 F.3d 1336
    , 1342 (Fed.
    Cir. 2018). Where, as here, there is no narrowing claim
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    PAR PHARMACEUTICAL, INC.   v. HOSPIRA, INC.                11
    construction proposed based on particular intrinsic-evi-
    dence statements or actions, the general considerations set
    forth in Cohesive govern. The extension effected by “about”
    must be tied to “the purpose of the limitation in the claimed
    invention—not the purpose of the invention itself.” 
    Id.
     It
    also requires examination of whether the extension is by a
    “modest amount,” Conopco, Inc. v. May Dep’t Stores Co., 
    46 F.3d 1556
    , 1562 (Fed. Cir. 1994), considering the “critical-
    ity of the [numerical limitation] to the invention,” Cohesive,
    543 F.3d at 1368 (quoting Ortho-McNeil Pharm., Inc. v.
    Caraco Pharm. Labs., Ltd., 
    476 F.3d 1321
    , 1327 (Fed. Cir.
    2007)) (alteration in original), as well as the “technologic
    and stylistic context” of the invention, Pall, 
    66 F.3d at 1217
    . Thus, in Conopco, we concluded that the ordinary
    and customary meaning of “about” could not extend the up-
    per bound of “‘about 40:1 to 1:1’” “as far as the prior art
    would allow” and could not reach as far as “162.9:1,” given
    the criticality of the ratio and that such an interpretation
    would result in an impermissible “expansion” of the term
    “about,” as opposed to a mere “stretch[]” by “a modest
    amount.” 
    46 F.3d at
    1560–62.
    Although defining the outer reaches of “about” in a
    claimed range can be a matter of claim construction,
    “[w]hen the claims are applied to an accused device, it is a
    question of technologic fact whether the accused device
    meets a reasonable meaning of ‘about’ in the particular cir-
    cumstances.” Modine Manufacturing Co. v. U.S. Int’l
    Trade Comm’n, 
    75 F.3d 1545
    , 1554 (Fed. Cir. 1996), abro-
    gated on other grounds by Festo Corp. v. Shoketsu Kinzoku
    Kogyo Kabushiki Co., 
    234 F.3d 558
     (Fed. Cir. 2000), rev’d,
    
    535 U.S. 722
     (2002).
    The district court’s analysis is consistent with our prec-
    edents. The parties agreed that “about” should be con-
    strued to have its “plain and ordinary meaning” of
    “approximately,” J.A. 76, with no further refinement as a
    claim-construction matter. The district court therefore
    properly focused on whether Hospira’s ANDA product,
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    12                 PAR PHARMACEUTICAL, INC.   v. HOSPIRA, INC.
    even the target 9 mg/mL sodium-chloride concentration,
    would come within the “about” range as a matter of fact.
    See Par, 420 F. Supp. 3d at 277; see also Modine, 
    75 F.3d at 1549
    . And the court reasonably concluded that it would:
    based on the analytic framework of Cohesive, the evidence
    supported a finding that “about 8” encompasses 9, consid-
    ering the purpose of the upper limit.
    The court credited Dr. Elder’s testimony on this point,
    Par, 420 F. Supp. 3d at 264–66, 277, which focused on the
    technological facts, the importance of the purpose of the
    limitation, and the limitation’s noncriticality. J.A. 155,
    158, 162–63. Dr. Elder explained the purpose of both ends
    of the claim range—to avoid hypertonicity of the solution
    (which would lead to cell shrinkage) and to avoid hypoto-
    nicity of the solution (which would lead to cell swelling) and
    thereby achieve isotonicity, which is the stated goal of Hos-
    pira’s inclusion of sodium chloride. J.A. 156–58. And he
    explained why it was clear that a “physiologically accepta-
    ble” concentration would include concentrations as high as
    9 mg/mL, there being nothing critical to the exact numbers
    in the claimed range given the purposes of the upper and
    lower limits. J.A. 160–61. The district court reasonably
    accepted this evidence, noting that Hospira’s Dr. Pinal “did
    not provide a meaningful analysis of the technologic con-
    text or the function of the claimed amount of tonicity regu-
    lating agent.” Par, 420 F. Supp. 3d at 277. We thus find
    no clear error with the district court’s finding, which “did
    not unduly interfere with the intended function of the
    claims, and did not eviscerate the plain meaning of the
    term ‘about.’” Conopco, 
    46 F.3d at 1562
    .
    Hospira contends that, years after the ’876 and ’657 pa-
    tent issued, Par made statements suggesting that 8.5
    mg/mL might be too high to be “about 6 to 8” in the course
    of prosecuting a continuation-in-part application that
    named a different inventor group, that had different
    claims, and that Par eventually abandoned. Hospira Op.
    Br. 41; J.A. 3958–59, 4008–09. We need not explore the
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    PAR PHARMACEUTICAL, INC.   v. HOSPIRA, INC.                 13
    force that such statements might have had if Hospira had
    proposed a narrowing claim construction; Hospira did not
    do so. With the agreed-upon “plain and ordinary meaning”
    construction adopted, the remaining issue was what a rel-
    evant artisan would reasonably understand to come within
    “about 6 to 8 mg/mL” given the “modest amount” by which
    the range is expanded, Conopco, 
    46 F.3d at 1562
    , and the
    purposes and absence of criticality of the bounds of the
    range in the ’876 and ’657 patents. Hospira has cited no
    authority that would make Par’s later statements, made in
    a different context, controlling over the evidence that the
    district court relied on here to find in Par’s favor on this
    claim limitation.
    B
    Hospira next argues that the district court erred in ac-
    cepting Par’s testimony that Hospira’s ANDA is for a prod-
    uct containing “about 0.01 to 0.4 mg/mL of a transition
    metal complexing agent.” Hospira’s argument is that the
    analysis should have focused entirely on the characteristics
    of the composition that Hospira was likely to sell, not on
    what compositions the ANDA, if approved, would allow
    Hospira to market. Hospira Op. Br. 51–60. We disagree.
    As a threshold matter, the district court did not commit
    clear error in finding that citric acid acts as a transition
    metal complexing agent in Hospira’s ANDA product. See
    Par, 420 F. Supp. 3d at 278. Hospira represented to the
    FDA that its citric acid buffer has a “chelating effect” al-
    lowing it to complex with transition metals. J.A. 4499.
    Hospira’s experts acknowledged at trial that citric acid has
    “chelating properties” and therefore could bind with ele-
    mental impurities in its product. J.A. 376, 754–55. It is
    not necessary that Hospira intended the citric acid to func-
    tion as a chelating agent if, as the district court could read-
    ily find, the citric acid actually does so. Global-Tech
    Appliances, Inc. v. SEB S.A., 
    563 U.S. 754
    , 761 n.2 (2011)
    Case: 20-1273    Document: 44      Page: 14    Filed: 11/23/2020
    14                 PAR PHARMACEUTICAL, INC.   v. HOSPIRA, INC.
    (citing Aro Mfg. Co. v. Convertible Top Replacement Co.,
    
    377 U.S. 476
    , 484 (1964)).
    The infringement statute for ANDAs states that sub-
    mission of an ANDA is “an act of infringement” if the
    ANDA is “for a drug claimed in a patent or the use of which
    is claimed in a patent.” 
    35 U.S.C. § 271
    (e)(2). Applying
    that language, we have held that “[w]hat a generic asks for
    and receives approval to market, if within the scope of a
    valid claim, is an infringement.” Sunovion Pharm., Inc. v.
    Teva Pharm., USA, Inc., 
    731 F.3d 1271
    , 1279 (Fed. Cir.
    2013); 
    id. at 1278
     (“[I]f a product that an ANDA applicant
    is asking the FDA to approve for sale falls within the scope
    of an issued patent, a judgment of infringement must nec-
    essarily ensue.”). Even where internal documents suggest
    that a generic product will not meet a claim limitation in
    practice, representations about the ANDA’s scope control
    the infringement analysis. 
    Id. at 1279
    . That does not
    mean that the filing of an ANDA suffices to show that a
    generic product meets any claim limitation not excluded by
    the ANDA. Glaxo, Inc. v. Novopharm, Ltd., 
    110 F.3d 1562
    ,
    1569–70 (Fed. Cir. 1997). When an ANDA is silent with
    respect to a claim limitation, Sunovion does not govern; it
    is the product that the generic company is likely to sell that
    guides the infringement analysis. Ferring B.V. v. Watson
    Labs., Inc.,-Fla., 
    764 F.3d 1382
    , 1387–88 (Fed. Cir. 2014).
    Here, we conclude, Sunovion governs. Hospira’s sole
    contention to the contrary is that the ANDA is silent about
    the presence of components that would establish whether
    the product meets the limitation requiring a defined
    amount of a transition metal complexing agent, i.e.,
    whether the ANDA sets an upper limit on such an agent.
    We reject Hospira’s contention: Hospira’s ANDA is not si-
    lent on the point. Whether or not the ANDA identifies a
    lower limit on the amount of a component that would meet
    the limitation, a point about which Hospira does not pre-
    sent any separate argument, the ANDA does identify an
    upper limit bearing directly on the limitation at issue.
    Case: 20-1273    Document: 44      Page: 15    Filed: 11/23/2020
    PAR PHARMACEUTICAL, INC.   v. HOSPIRA, INC.               15
    It is not disputed before us that the amount of transi-
    tion metal complexing agent is a simple function of the
    amount of elemental impurities in the form of transition
    metals in the composition. The ANDA states in a line entry
    in a table that its product satisfies the ICH Q3D guidelines,
    meaning that it can market and sell a product with up to
    30% of the permitted daily exposure of transition metal im-
    purities. J.A. 1043. That line entry was added by Hospira
    in response to an FDA request for “adequate information”
    showing that its ANDA product would comply with ICH
    Q3D. J.A. 4528 ¶ 8; see also J.A. 4545 (Hospira informed
    the FDA that its “specifications [were] updated” to demon-
    strate that its product met the required elemental impurity
    guidelines). These disclosures to the FDA are sufficient to
    support the district court’s finding that “there are clearly
    metals” in Hospira’s ANDA product and that the amount
    of transition metals can “vary,” as Hospira’s Dr. Gokel ad-
    mitted, and is “not subject to control.” Par, 420 F. Supp. 3d
    at 278; J.A. 166–67.
    Thus, unlike in Ferring, the ANDA is not silent as to
    whether Hospira’s product could contain sufficient concen-
    trations of elemental impurities such that citric acid would
    complex with the transition metals in a high enough con-
    centration to satisfy the limitation requiring “about 0.01 to
    0.4 mg/mL of a transition metal complexing agent.” See
    Ferring, 764 F.3d at 1387–88. Sunovion therefore applies.
    We reject Hospira’s challenge regarding this claim limita-
    tion.
    C
    Finally, Hospira argues that the trial court erred in
    finding—without sufficient analysis—that its ANDA co-
    vers a product containing “about 0.001 to 0.010 mL/mL of
    a pH lowering agent.” Specifically, Hospira argues that the
    trial court improperly accepted Par’s counting not just hy-
    drochloric acid but also citric acid as a pH lowering agent.
    Hospira contends that citric acid—specifically, the citric
    Case: 20-1273     Document: 44      Page: 16   Filed: 11/23/2020
    16                 PAR PHARMACEUTICAL, INC.   v. HOSPIRA, INC.
    acid that remains after subtracting the amount that serves
    as a transition metal complexing agent—cannot be a pH
    lowering agent because it is already included in the buffer
    system that counts toward meeting the claim limitation re-
    quiring a certain amount of pH raising agent. Hospira Op.
    Br. 60–63. We disagree.
    Hospira has not made and preserved a claim-construc-
    tion argument that, in these patents, an acid, i.e., a pH low-
    ering agent, cannot also be part of an agent that overall
    serves to raise pH. Indeed, the passages of the specifica-
    tion of the ’876 and ’657 patents that discuss a “buffer sys-
    tem” made up of an acid and a base, quoted supra, at least
    strongly suggest the opposite. Rather than disputing the
    suggestion, Hospira agreed to claim constructions based di-
    rectly on the specification passages. See J.A. 76; note 2,
    supra. We therefore reject Hospira’s argument that citric-
    acid molecules must be allocated between the pH raising
    agent limitation and the pH lower agent limitation. And
    with that argument rejected, there is no clear error in the
    district court’s finding that Hospira’s ANDA product would
    have a pH lowering agent (citric acid, after subtracting
    those molecules that bind to transition metals) in an
    amount that comes within the concentration range re-
    quired by the claims. Par, 420 F. Supp. 3d at 270–71, 277–
    78.
    III
    The district court’s judgment is affirmed.
    Each party shall bear its own costs.
    AFFIRMED