       NOTE: This disposition is nonprecedential.

  United States Court of Appeals
      for the Federal Circuit
              __________________________

            RECKITT BENCKISER INC.,
                Plaintiff-Appellant,
                           v.
   WATSON LABORATORIES, INC. - FLORIDA,
             Defendant-Appellee.
              __________________________

                      2011-1231
              __________________________

   Appeal from the United States District Court for the
Southern District of Florida in Case No. 09-CV-60609,
Judge William P. Dimitrouleas.
              __________________________

                 Decided: July 7, 2011
              __________________________

    DOMINICK A. CONDE, Fitzpatrick, Cella, Harper &
Scinto, of New York, New York, argued for the plaintiff-
appellant. With him on the brief were JOHN D. CARLIN,
NINA SHREVE and TARA A. BYRNE.

    B. JEFFERSON BOGGS, Merchant & Gould, of Alexan-
dria Virginia, argued for defendant-appellee. Of counsel
on the brief were SUSAN BAKER MANNING, MATTHEW L.
RECKITT BENCKISER   v. WATSON LABS                      2


FEDOWITZ and ANDREW B. ELLSWORTH,               Bingham
McCutchen, LLP, of Washington, DC.
             __________________________

     Before LOURIE, LINN, and DYK, Circuit Judges.
LOURIE, Circuit Judge.
     Reckitt Benckiser Inc. (“Reckitt”) appeals from the
judgment of the United States District Court for the
Southern District of Florida holding that Watson Labora-
tories, Inc. - Florida (“Watson”) does not infringe the
asserted claims of U.S. Patent 6,372,252 (the “’252 pat-
ent”). Reckitt Benckiser, Inc. v. Watson Labs., Inc. –
Florida, No. 09-cv-60609, slip op. (S.D. Fla. Feb. 18,
2011), ECF No. 339. Because the district court correctly
construed the asserted claims of the ’252 patent and
determined that Watson’s products do not infringe, we
affirm.
                       BACKGROUND
                             I
    At issue in this case are pharmaceutical formulations
comprising guaifenesin, an expectorant useful for reliev-
ing congestion. Reckitt obtained approval from the Food
and Drug Administration (“FDA”) to market its Mucinex®
products, bilayer tablets containing guaifenesin in both
immediate release (“IR”) and sustained release (“SR”)
formulations. Reckitt listed the ’252 patent in the FDA’s
Approved Drug Products with Therapeutic Equivalence
Evaluations (the “Orange Book”) as covering Mucinex®.
    The ’252 patent states that IR formulations of
guaifenesin were known in the art. ’252 patent col.3 ll.7-
11. The patent also states that although SR formulations,
including polymer-based formulations containing a hy-
drophilic hydrocolloid gelling polymer, were known gen-
3                        RECKITT BENCKISER   v. WATSON LABS


erally, id. col.1 l.57–col.2 l.14, SR formulations of
guaifenesin capable of sustaining therapeutic effective-
ness for at least twelve hours were not known as of the
patent’s filing date, id. col.3 ll.12-14.
    The prosecution history of the ’252 patent is relevant
to the arguments on appeal. Originally filed claims 1-11
were directed to “[a] sustained release pharmaceutical
formulation” and were not limited to a bilayer or two-
portion structure. Reckitt, slip op. at 22; J.A. 41996-97.
Original claims 12-32, in contrast, were directed to modi-
fied release products. Reckitt, slip op. at 23; J.A. 41997-
42000. Claims 12-24 were limited to products with two
portions, while claims 25-32 were directed to modified
release tablets with a Cmax equivalent to an IR guaifene-
sin tablet and a twelve-hour therapeutic bioavailability.
    As the district court noted, the examiner rejected
original claims 1-32 as being unpatentable for obvious-
ness under 35 U.S.C. § 103(a) over two prior art refer-
ences. Reckitt, slip op. at 23; J.A. 42201. In response, the
applicants filed an amendment on August 6, 2001, cancel-
ling those claims and adding new claims 33-55, all of
which were directed to “[a] modified release tablet having
two portions.” Reckitt, slip op. at 23; J.A. 42216, 42213-
14. In remarks accompanying that amendment, the
applicants stated that, to facilitate prosecution, they were
relinquishing claims directed to guaifenesin SR formula-
tions:
    Claims 1-32 have been cancelled and claims 33-55
    have been added. Original claims 1-11 were di-
    rected to a sustained release formulation and
    claims 12-32 were directed to a modified release
    formulation having both immediate and sustained
    release properties. New claims 33-55 are directed
    to the modified release formulation of original
RECKITT BENCKISER   v. WATSON LABS                          4


   claims 12-32, while the sustained release claims
   have been cancelled to facilitate prosecution with-
   out prejudice to Applicants’ ability to pursue them
   separately in a continuation application.
Reckitt, slip op. at 23; J.A. 42214, 42208 (emphases
added). The applicants also distinguished new claims 33-
55 over the two cited prior art references, arguing that the
new claims, unlike the prior art, required two portions:
       Drost et al. does not disclose a composition
   having both an immediate release portion that is
   fully bioavailable in the subject’s stomach and a
   sustained release portion that provides therapeu-
   tically effective bioavailability for at least 12
   hours. . . .
       Dansereau et al. does not supply the deficien-
   cies of Drost et al. While Dansereau et al. does
   disclose two separate guaifenesin portions with
   different release characteristics, this disclosure de-
   scribes a dual-action tablet that includes an outer
   portion that slowly releases a first dose of the
   drug and an inner portion that provides a second
   dose which is delayed until some time after ad-
   ministration, i.e., until the outer portion is dis-
   solved sufficiently to expose the inner portion to
   gastric fluids. Such an approach is totally differ-
   ent from that of the claimed invention. In fact,
   Dansereau et al. specifically teaches away from
   employing any immediate release portion: “This
   dual-action tablet is contrasted with repeat-action
   tablets which give an immediate dose followed by
   a sustained dose” . . . . Moreover, the inner dose of
   Dansereau et al. is not “fully bioavailable in the
   subject’s stomach” because of the time delay
   caused by the slow-release outer portion.
5                         RECKITT BENCKISER    v. WATSON LABS


Reckitt, slip op. at 23-24 (emphases added).
    On November 19, 2001, following an interview with
the examiner, the applicants filed a supplemental
amendment. Id. at 24; J.A. 42302-12. At the examiner’s
suggestion, this amendment added a further limitation to
claims 33, 42-44, 46, and 48 requiring the tablet to dem-
onstrate a particular Cmax. The applicants also intro-
duced new claims 56-88. Those claims all required “[a]
modified release product having two portions.” J.A.
42303-05. In remarks accompanying the supplemental
amendment, the applicants again distinguished the prior
art from the pending claims as lacking both an IR portion
and an SR portion. Reckitt, slip op. at 25-26; J.A. 42306-
08.
    In a notice of allowance dated December 4, 2001, the
examiner indicated that the pending claims “are allow-
able over the prior art because the prior art does not teach
a modified release bi-layer tablet product that provides
early Tmax or the higher Cmax achievable with the
claimed invention.” Reckitt, slip op. at 26; J.A. 42317.
The claims issued as claims 1-56 of the ’252 patent.
Claims 57 and 58 were added during ex parte reexamina-
tion; those claims are also directed to “[a] modified release
product having two portions.” J.A. 124.
                             II
    In April 2009, Reckitt sued Watson in the United
States District Court for the Southern District of Florida
for infringing independent claims 24, 57, and 58 and
dependent claims 26-28, 31-34, and 39 of the ’252 patent
based on Watson’s abbreviated new drug application
(“ANDA”) to market guaifenesin tablet formulations. 35
U.S.C. § 271(e)(2). The claim limitation disputed on
appeal appears in each of the asserted independent
claims. Claim 24 is illustrative:
RECKITT BENCKISER   v. WATSON LABS                         6


   24. A modified release product having two por-
   tions, wherein a first portion comprises a first
   quantity of guaifenesin in an immediate release
   form which becomes fully bioavailable in the sub-
   ject’s stomach and a second portion comprises a
   second quantity of guaifenesin in a sustained re-
   lease form wherein the ratio of said first quantity
   to said second quantity provides a Cmax in a hu-
   man subject equivalent to the Cmax obtained
   when the first of three doses of a standard imme-
   diate release formulation having one third the
   amount of guaifenesin is dosed every four hours
   over a 12 hour period and wherein said product
   also provides therapeutically effective bioavail-
   ability for at least twelve hours after a single dose
   in a human subject according to serum analysis.
’252 patent claim 24 (emphases added).
    Watson’s accused products are non-layered polymer
matrix tablets made from a single guaifenesin formula-
tion. 1 Reckitt, slip op. at 47. In its ANDA, Watson sought
a determination by the FDA that its products are bio-
equivalent to the Mucinex® products. Id. at 36-37.
    In January 2011, the district court issued a claim con-
struction order which, inter alia, construed “portion” as “a
discrete part of the product.” J.A. 5520; see also Reckitt,
slip op. at 41. Following a 7-day bench trial, the court
found that Watson’s products do not have separate IR and
SR portions and thus do not literally infringe the ’252
patent. Reckitt, slip op. at 43-51. The court did not view
as credible Reckitt’s theory that guaifenesin granules on
the surface of Watson’s product constituted a discrete IR

   1  Detailed information concerning the ingredients,
manufacture, and performance of Watson’s tablets has
been marked as confidential by the parties.
7                        RECKITT BENCKISER   v. WATSON LABS


portion. Id. at 48-49. The court concluded that during
prosecution Reckitt disclaimed products lacking two
discrete structural portions. Id. at 44-45. Further, the
court found no infringement under the doctrine of equiva-
lents, because the “two portions” structural limitation is
not present in Watson’s products and because Watson’s
tablets achieve bioavailability in a different way from the
claimed tablets. Id. at 53-57.
    The district court entered final judgment of nonin-
fringement on February 9, 2011. Pursuant to 28 U.S.C.
§ 1295(a)(1), we have jurisdiction over final judgments
arising under the patent laws.
                       DISCUSSION
     Reckitt appeals the district court’s claim construction
and its findings of noninfringement both literally and
under the doctrine of equivalents. According to Reckitt,
the court misconstrued the claim term “portion” in the
asserted claims. Reckitt contends that the written de-
scription of the ’252 patent does not limit the invention to
discrete bilayered tablets. Reckitt cites Rexnord Corp. v.
Laitram Corp., 274 F.3d 1336, 1344 (Fed. Cir. 2001) in
support of its argument that the district court erred by
failing to apply the ordinary meaning of the term “por-
tion,” which is “a part of any whole.” Reckitt maintains
that the doctrine of claim differentiation supports its
construction of the term portion. Moreover, Reckitt
contends that the prosecution history of the ’252 patent
does not limit “portion” to a “discrete part.”
    As for infringement, Reckitt contends that the district
court ignored its own claim construction and based its
finding of noninfringement on new process limitations.
Reckitt also alleges that granules of guaifenesin on the
surface of Watson’s products constitute a discrete IR
portion such that Watson’s products literally infringe the
RECKITT BENCKISER   v. WATSON LABS                        8


asserted claims of the ’252 patent even under the district
court’s claim construction. Reckitt further asserts that
the district court’s finding of noninfringement under the
doctrine of equivalents was clearly erroneous because the
court merely reiterated its analysis of literal infringement
and failed to properly apply the function-way-result test.
Finally, Reckitt maintains that it did not disclaim non-
layered tablets during prosecution because canceled
original claims 1-11 claimed a particular ratio of hydro-
philic polymer to water insoluble polymer without regard
to Cmax or PK profile.
    In response, Watson argues that the court correctly
found that its accused products do not infringe the as-
serted claims, as properly construed by the district court.
According to Watson, the specification states that the
claimed portions must be discrete. Watson also asserts
that Reckitt disclaimed non-layered SR formulations
during prosecution, and that the court’s claim construc-
tion correctly accounts for this disclaimer. Although
Watson acknowledges that granules on the surface of its
products release guaifenesin upon ingestion, Watson
insists these do not constitute a “portion” of the tablet
within the meaning of the ’252 patent’s claims. Thus,
Watson contends, the court correctly found that its prod-
ucts do not literally infringe the ’252 patent because they
are non-layered, single-formulation polymer matrix
tablets that do not have two portions as the asserted
claims require.
    Watson also argues that the court correctly found that
its products do not infringe under the doctrine of equiva-
lents. According to Watson, the ’252 patent discloses non-
layered, single-formulation tablets but does not claim
them; therefore, they are dedicated to the public. Watson
further asserts that prosecution history estoppel also
precludes infringement under the doctrine of equivalents.
9                        RECKITT BENCKISER   v. WATSON LABS


Watson alleges that the district court correctly concluded
that Reckitt may not use the doctrine of equivalents to
read out the “two portions” limitation of the asserted
claims.
    We agree with Watson that the district court did not
err in its claim construction and did not clearly err in its
finding of a lack of infringement. A district court’s claim
construction is a matter of law that we review de novo.
Cybor Corp. v. FAS Techs., Inc., 138 F.3d 1448, 1454-55
(Fed. Cir. 1998) (en banc). We consider the claim lan-
guage, specification, prosecution history, and relevant
extrinsic evidence in ascertaining the scope and meaning
of the claims. Phillips v. AWH Corp., 415 F.3d 1303,
1314-17 (Fed. Cir. 2005) (en banc). “[A]bsent contraven-
ing evidence from the specification or prosecution history,
plain and unambiguous claim language controls the
construction analysis.” DSW, Inc. v. Shoe Pavilion, Inc.,
537 F.3d 1342, 1347 (Fed. Cir. 2008). However, “when a
patent applicant surrendered claim scope during prosecu-
tion before the PTO, the ordinary and customary meaning
of a claim term may not apply.” Elbex Video, Ltd. v.
Sensormatic Elecs. Corp., 508 F.3d 1366, 1371 (Fed. Cir.
2007). To narrow the scope of claim language, a prosecu-
tion history disclaimer must be “clear and unambiguous.”
Seachange Int’l, Inc. v. C-COR Inc., 413 F.3d 1361, 1373
(Fed. Cir. 2005).
    Infringement is a question of fact that, after a bench
trial, we review for clear error. Alza Corp. v. Mylan Labs.,
Inc., 464 F.3d 1286, 1289 (Fed. Cir. 2006). A factual
finding is clearly erroneous when, despite some support-
ing evidence, we are left with a definite and firm convic-
tion that the district court was in error. Id.
    Regarding claim construction, we conclude that the
district court did not err by construing the term “portion”
RECKITT BENCKISER   v. WATSON LABS                        10


to mean “a discrete part of the product.” The court’s claim
construction rested on a proper analysis of the claims and
written description of the ’252 patent, as well as its prose-
cution history. Reckitt, slip op. at 7-29. The ’252 patent
discloses two general types of guaifenesin formulations—
SR formulation tablets and modified release tablets with
both IR and SR portions. Id. at 7-10. The specification
never refers to the SR formulation tablets as containing
“portions.” Id. at 10. In contrast, the modified release
tablets disclosed in the specification include three em-
bodiments: bilayer tablets having an IR portion on one
face and an SR portion on the other; bilayer tablets hav-
ing an SR portion in the center that is coated and sur-
rounded by an IR portion; and guaifenesin capsules
containing beads of IR formulation and beads of SR
formulation. Id. at 22; ’252 patent col.3, ll.57-60; col.9,
ll.46-56. The specification explicitly states that the modi-
fied release tablets contain “two discrete portions.” ’252
patent col.3, ll.44-48.
    In the context of the ’252 patent’s disclosure, which
clearly distinguishes between SR formulation tablets and
two-portion modified release products, the district court
properly considered the prosecution history, including the
amendments and remarks made by the applicants during
prosecution of the application leading to the ’252 patent.
Reckitt, slip op. at 22-26. The court correctly concluded
that the prosecution history demonstrated a disclaimer of
single-formulation SR guaifenesin tablets, even if those
tablets release some guaifenesin immediately upon inges-
tion. Id. at 45 (characterizing the prosecution history as a
“disclaimer of products with merely immediate release
and sustained release properties,” as opposed to products
with discrete IR and SR portions). The applicants dis-
avowed claim coverage of sustained release tablets by
cancelling original claims 1-11 and remarking to the
11                       RECKITT BENCKISER   v. WATSON LABS


examiner that “[o]riginal claims 1-11 were directed to a
sustained release formulation . . . .     [T]he sustained
release claims have been cancelled to facilitate prosecu-
tion.” Id. at 23. The unmistakable effect of that dis-
avowal,     evident   from   the    applicants’   remarks
distinguishing the prior art, was to limit the remaining
claims to two-portion guaifenesin products. For instance,
the applicants distinguished one reference by arguing
that it “does not disclose a composition having both an
immediate release portion that is fully bioavailable in the
subject’s stomach and a sustained release portion that
provides therapeutically effective bioavailability for at
least 12 hours.” Id. at 24. The file history thus demon-
strates a “clear and unambiguous” prosecution disclaimer.
Seachange, 413 F.3d at 1373.
    The district court’s construction of the “portion” limi-
tation not only accurately encompasses the three em-
bodiments of two-portion tablets and capsules disclosed in
the specification, it also excludes single-formulation SR
tablets such as those disclosed in the ’252 patent. Reckitt,
slip op. at 44-51. The district court’s claim construction,
therefore, properly accounted for the patent’s disclosure
and the applicants’ clear and unmistakable prosecution
history disclaimer. See N. Am. Container, Inc. v. Plasti-
pak Packaging, Inc., 415 F.3d 1335, 1345 (Fed. Cir. 2005)
(concluding that the applicant, through arguments during
prosecution, met “the high standard required in order to
show a prosecution disclaimer”). Even if, as Reckitt
argues, the district court’s construction departs from the
ordinary meaning of the term “portion,” cf. Rexnord, 274
F.3d at 1344, we nevertheless affirm the court’s construc-
tion of this term in the context of the ’252 patent. See
Omega Eng’g, Inc. v. Raytek Corp., 334 F.3d 1314, 1324
(Fed. Cir. 2003) (“[W]here the patentee has unequivocally
disavowed a certain meaning to obtain his patent, the
RECKITT BENCKISER   v. WATSON LABS                         12


doctrine of prosecution disclaimer attaches and narrows
the ordinary meaning of the claim congruent with the
scope of the surrender.”).
      We also reject Reckitt’s contention that the doctrine of
claim differentiation runs contrary to the district court’s
claim construction. Under the doctrine of claim differen-
tiation, “the presence of a dependent claim that adds a
particular limitation raises a presumption that the limita-
tion in question is not found in the independent claim[,]
[a]lthough that presumption can be overcome if the cir-
cumstances suggest a different explanation, or if the
evidence favoring a different claim construction is strong
. . . .” Liebel-Flarsheim Co. v. Medrad, Inc., 358 F.3d 898,
910 (Fed. Cir. 2004) (citations omitted). Reckitt main-
tains that the district court’s construction of claim 24 is
erroneously limited to bilayer tablets and that this con-
struction renders superfluous unasserted dependent claim
36, directed specifically to bilayer tablets. We disagree.
As we noted above, the district court’s construction en-
compasses the three embodiments of two-portion tablets
and capsules in the specification; thus, a dependent claim
directed only to one particular type of bilayer tablet is
fully consistent with the doctrine of claim differentiation.
See 35 U.S.C. § 112 ¶ 4 (2006).
    Reckitt’s additional claim construction arguments are
unpersuasive. Accordingly, we affirm the district court’s
construction of the term “portion,” the only claim term at
issue in this appeal.
    Further, we reject Reckitt’s arguments that the court
clearly erred in its analysis of literal infringement. Con-
trary to Reckitt’s assertions, the district court did not
ignore its own claim construction and base its finding of
noninfringement on new process limitations. As the court
correctly found, Watson’s products do not infringe because
13                        RECKITT BENCKISER   v. WATSON LABS


they are non-layered, single-formulation polymer matrix
tablets that do not contain the claimed “first portion” or
“second portion.” Reckitt, slip op. at 45-47. Moreover, we
reject Reckitt’s contention that Watson’s products do not
infringe under a proper application of the district court’s
claim construction. The district court correctly concluded
that Watson’s products do not have two structural por-
tions and that guaifenesin granules on the surface of
Watson’s tablets do not constitute the claimed first por-
tion of guaifenesin in an IR form. Id. at 48-51. As the
court noted, even though the SR formulations that Reckitt
disclaimed during prosecution of the ’252 patent exhibit
some IR properties, they do not possess a two-portion
structure. Id. at 45; see also J.A. 43344-45. Likewise,
even if Watson’s products exhibit some IR properties (as
Reckitt maintains), they do not contain a discrete IR
portion as required by the asserted claims. Reckitt, slip
op. at 45.
    Finally, Reckitt contends that the district court
clearly erred in its finding of noninfringement under the
doctrine of equivalents. Again, we disagree. Reckitt
asserts, in essence, that bioequivalence necessitates
infringement by equivalence. We have clarified, however,
that “bioequivalency and equivalent infringement are
different inquiries.” Abbott Labs. v. Sandoz, Inc., 566
F.3d 1282, 1298 (Fed. Cir. 2009). Indeed, on the facts of
this case, prosecution history estoppel bars Reckitt from
recapturing single-formulation SR guaifenesin tablets like
those it disclaimed in obtaining the ’252 patent. Reckitt,
slip op. at 55. As the district court correctly noted,
Reckitt’s narrowing claim amendments were made for
reasons of patentability. Id. at 23, 25; see also Festo Corp.
v. Shoketsu Kinzoku Kogyo Kabushiki Co., 535 U.S. 722,
736 (2002) (“Estoppel arises when an amendment is made
to secure the patent and the amendment narrows the
RECKITT BENCKISER   v. WATSON LABS                        14


patent’s scope.”). When, in response to an examiner’s
rejection, a patent applicant submits an amended claim
set, the applicant’s “decision to forgo an appeal and sub-
mit an amended claim is taken as a concession that the
invention as patented does not reach as far as the original
claim.” Id. at 734. We, like the district court, take
Reckitt’s unambiguous prosecution disclaimer as a con-
cession that the asserted claims of the ’252 patent do not
extend to single-formulation SR tablets such as Watson’s
accused products. 2 Reckitt, slip op. at 55-56.
                        CONCLUSION
    We have considered Reckitt’s remaining arguments
and find them unpersuasive. Accordingly, for the forego-
ing reasons, we affirm the district court’s finding of nonin-
fringement.
                       AFFIRMED




    2   This case also appears to invoke the dedication
doctrine, whereby the failure to claim a disclosed em-
bodiment forecloses any right to recapture that embodi-
ment under the doctrine of equivalents. See Abbott, 566
F.3d at 1297; Johnson & Johnston Assocs. v. R.E. Serv.
Co., 285 F.3d 1046, 1054 (Fed. Cir. 2002) (en banc).
However, because we conclude that prosecution history
estoppel limits the application of the doctrine of equiva-
lents in this case, we need not separately address the
dedication doctrine.
