Otsuka America Pharmaceutical, Inc., Avanir Pharmaceuticals, LLC, Fka Avanir… v. Hetero Labs Limited, Hetero Labs Limited Unit-Iii, Camber Pharmaceuticals Inc.

United States Court of Appeals
for the Federal Circuit
______________________
OTSUKA AMERICA PHARMACEUTICAL, INC.,
AVANIR PHARMACEUTICALS, LLC, FKA AVANIR
PHARMACEUTICALS INC.,
Plaintiffs-Appellees
v.
HETERO LABS LIMITED, HETERO LABS LIMITED
UNIT-III, CAMBER PHARMACEUTICALS INC.,
Defendants-Appellants
______________________
2025-2016
______________________
Appeal from the United States District Court for the
District of Delaware in No. 1:25-cv-00647-GBW, Judge
Gregory Brian Williams.
______________________
Decided: July 1, 2026
______________________
ERIC C. STOPS , Quinn Emanuel Urquhart & Sullivan,
LLP, New York, NY, argued for plaintiffs-appellees. Also
represented by J AMES BAKER , F RANCIS D OMINIC CERRITO,
J OHN G ALANEK, ELLYDE R. T HOMPSON; ALEXANDRA K IM ,
Boston, MA.
EHAB M. SAMUEL , Orbit IP, LLP, Newport Beach, CA,
argued for defendants-appellants. Also represented by
D AVID A. RANDALL , Los Angeles, CA.
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______________________
Before D YK, BRYSON, and STOLL , Circuit Judges.
Opinion for the court filed by Circuit Judge BRYSON.
Opinion dissenting-in-part and concurring-in-part filed by
Circuit Judge D YK.
BRYSON, Circuit Judge.
Hetero Labs Limited (“Hetero”) appeals from an order
granting a preliminary injunction in this patent case. The
district court’s order enjoined Hetero from introducing a
generic drug to compete with Nuedexta, a drug used for
treating neurological disorders. In granting the prelimi-
nary injunction, the court concluded that Otsuka America
Pharmaceutical, Inc., and its subsidiary, Avanir Pharma-
ceuticals, LLC (collectively, “Otsuka”), would be likely to
succeed in proving that Hetero’s product would infringe
U.S. Patent No. 7,659,282 (“the ’282 patent”), owned by
Avanir, and that the relevant equitable factors favored
granting the injunction.
The issues on appeal are (1) whether the district court
properly interpreted the terms “dextromethorphan” and
“quinidine” in the weight-to-weight ratio limitation in
claim 1 of the ’282 patent, and (2) whether the district court
permissibly waived the requirement imposed by Federal
Rule of Civil Procedure 65(c) that Otsuka post a bond pend-
ing appeal. We affirm the district court’s construction of
the disputed claim terms, but we vacate the district court’s
order waiving the requirement of a bond pending appeal.
I
The ’282 patent covers a method for treating pseudo-
bulbar affect or emotional lability, which is the inability to
control emotions exhibited by patients with neurodegener-
ative diseases or after a stroke or other brain injury. ’282
patent, col. 1, ll. 39–51; col. 2, ll. 7–21. The patented
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method involves administering the drug dextrome-
thorphan in combination with a second drug, quinidine.
Dextromethorphan provides the therapeutic effect, while
quinidine protects the dextromethorphan from rapid me-
tabolism by the liver. Id. at col. 2, ll. 19–21; col. 14, ll. 6–
28. The ’282 patent is scheduled to expire on August 13,
2026. J.A. 263.
Independent claim 1 of the ’282 patent reads as follows:
1. A method for treating pseudobulbar affect or
emotional lability, the method comprising administer-
ing to a patient in need thereof dextromethorphan in
combination with quinidine, wherein the amount of
dextromethorphan administered comprises from about
20 mg/day to about 80 mg/day and wherein the amount
of quinidine administered comprises from about 10
mg/day to less than about 30 mg/day with the proviso
that the weight to weight ratio of dextromethorphan to
quinidine is 1:0.5 or less.
’282 patent, col. 78, ll. 2–10.
Nuedexta, a branded pharmaceutical drug owned by
Otsuka, combines dextromethorphan and quinidine in
their salt forms. J.A. 17 at n.1; J.A. 21 at n.3. Nuedexta
capsules each contain 20 milligrams (“mg”) of dextrome-
thorphan hydrobromide and 10 mg of quinidine sulfate.
J.A. 861; see J.A. 17, 20. In August 2024, the U.S. Food and
Drug Administration (“FDA”) approved Hetero’s Abbrevi-
ated New Drug Application (“ANDA”) for a generic product
with the same indications as Nuedexta, including the same
amounts of dextromethorphan hydrobromide and quini-
dine sulfate. J.A. 17, 336.
When Hetero signaled its intention to launch its ge-
neric product on or after July 10, 2025, Otsuka filed a law-
suit in the United States District Court for the District of
Delaware seeking a temporary restraining order and a pre-
liminary injunction to prevent Hetero from entering the
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market. J.A. 2, 18. After first issuing a temporary re-
straining order, the district court granted Otsuka’s motion
for a preliminary injunction on July 23, 2025. J.A. 14, 33–
34. The district court did not require Otsuka to post a bond
pending appeal, because it found that “the equities
weigh[ed] strongly in favor of waiving the Rule 65(c) bond.”
J.A. 32. Hetero appeals the district court’s grant of the pre-
liminary injunction and the court’s order waiving the bond
requirement.
II
We review the grant of a preliminary injunction for an
abuse of discretion, which “may be established by showing
that the court made a clear error of judgment in weighing
relevant factors or exercised its discretion based upon an
error of law or clearly erroneous factual findings.” Astra-
Zeneca LP v. Apotex, Inc., 633 F.3d 1042, 1049 (Fed. Cir.
2010) (quoting Amazon.com, Inc. v. Barnesandnoble.com,
Inc., 239 F.3d 1343, 1350 (Fed. Cir. 2001)). Claim construc-
tion is a question of law that we review de novo, while re-
viewing any underlying factual determinations for clear
error. Teva Pharms. USA, Inc. v. Sandoz, Inc., 574 U.S.
318, 332–33 (2015).
Because the bond requirement in Rule 65(c) is not a
matter specific to patent law, we apply regional circuit law
to that issue, which in this case is Third Circuit law. In the
Third Circuit, the requirement to impose a bond is “strictly
interpreted,” and waiver is appropriate only under certain
limited exceptions. See Elliott v. Kiesewetter, 98 F.3d 47,
59–60 (3d Cir. 1996); Zambelli Fireworks Mfg. Co. v. Wood,
592 F.3d 412, 425–26 (3d Cir. 2010). A court’s decision as
to the amount of the bond is reviewed for an abuse of dis-
cretion. Boynes v. Limetree Bay Ventures LLC, 110 F.4th
604, 611 (3d Cir. 2024) (citation omitted).
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III
The primary issue in this case involves the construc-
tion of the terms “dextromethorphan” and “quinidine” as
used in the weight-to-weight ratio recited in claim 1 of the
’282 patent. According to the claim, “the weight to weight
ratio of dextromethorphan to quinidine is 1:0.5 or less.” It
is undisputed that the ’282 patent provides for the admin-
istration of dextromethorphan and quinidine in the form of
their pharmaceutically acceptable salts. The claim con-
struction dispute concerns the method for calculating the
ratio of dextromethorphan to quinidine when the dextro-
methorphan and quinidine are administered in their salt
forms. While at first blush it is appealing to construe the
terms “dextromethorphan” and “quinidine” to refer only to
the free base forms of those compounds, a close analysis of
the claims and specification of the ’282 patent leads us to
construe those terms as referring to the compounds
whether in free base or salt form.
Hetero argues that the correct construction of the dis-
puted terms requires the weight-to-weight ratio of the two
compounds to be calculated based on the weight of the ac-
tive moiety components of the compounds that are admin-
istered to the patient. According to Hetero, if those
compounds are administered in salt form, the weight of the
active moiety component of each compound must be used
as the basis for determining the weight-to-weight ratio of
the two compounds.
Applying the conversion ratio disclosed in the patent,
20 mg of dextromethorphan hydrobromide contains 15.4
mg of the dextromethorphan component of the compound,
and 10 mg of quinidine sulfate contains 8.7 mg of the quin-
idine component of the compound. See ’282 patent, col. 17,
line 63, through col. 18, line 14. Using that method of de-
termining the weight of the dextromethorphan and quini-
dine components, the weight-to-weight ratio of Hetero’s
generic product would be 1:0.56, which falls outside the
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ratio of “1:0.5 or less” recited in claim 1 of the ’282 patent.
Based on that calculation, Hetero contends that the district
court erred in finding that Otsuka was likely to succeed on
the merits of its infringement claims, and that the court
should not have granted the preliminary injunction. Br.
47–48.
According to Otsuka, such a conversion is not required
because the weight-to-weight ratio should be calculated
based on the amounts of the dextromethorphan and quini-
dine compounds administered to the patient, regardless of
whether those compounds are in free base or salt form. Br.
43. Following Otsuka’s construction, a formulation consist-
ing of 20 mg of dextromethorphan hydrobromide and 10 mg
of quinidine sulfate results in a weight-to-weight ratio of
1:0.5. Likewise, a formulation consisting of 20 mg of dex-
tromethorphan and 10 mg of quinidine in their free base
forms would result in the same ratio. Under Otsuka’s con-
struction, both Nuedexta and Hetero’s generic product fall
within the scope of claim 1, while under Hetero’s construc-
tion, neither product would be covered by claim 1.
Based on the references to the salt forms of dextrome-
thorphan and quinidine in the dependent claims and the
specification’s discussion of the salt forms of the com-
pounds, the district court was unpersuaded by Hetero’s ar-
gument that “the compounds listed in the ’282
patent . . . should be construed to mean those compounds
in their ‘free base’ forms.” J.A. 21. We agree with the dis-
trict court that Otsuka’s proposed construction is more con-
sistent with the manner in which the terms
“dextromethorphan” and “quinidine” are used in the pa-
tent, and that Otsuka’s proposed construction is preferable
to Hetero’s.
A
We begin with the intrinsic evidence and look first to
the claims. See Phillips v. AWH Corp., 415 F.3d 1303,
1312–17 (Fed. Cir. 2005) (en banc). Claim differentiation
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and consistent usage of the term in claim 1 point toward
Otsuka’s construction.
To begin with, the claims as a whole indicate that the
terms “dextromethorphan” and “quinidine” refer not only
to the free base forms of dextromethorphan and quinidine,
but to the salt forms as well. Claim 7, which depends from
claim 1, requires that the dextromethorphan or quinidine
“is in a form of a pharmaceutically acceptable salt.” ’282
patent, col. 78, ll. 26–28. Dependent claim 8 similarly re-
fers to “at least one of the quinidine and the dextrome-
thorphan . . . in a form of a pharmaceutically acceptable
salt.” Id. at col. 78, ll. 29–31. Because the dependent
claims include administration of those compounds in salt
form, the references to “dextromethorphan” and “quini-
dine” in the independent claim from which those claims de-
pend must also be understood to include the salt forms of
the two compounds. Underscoring that point, the fact that
claim 7 refers to dextromethorphan and quinidine “in the
form of a pharmaceutically acceptable salt” further indi-
cates that the salts of those compounds fall within the def-
inition of dextromethorphan and quinidine as those terms
are used in the patent.1
1 Hetero argues (Br. 38) that Otsuka and the district
court have adopted the “false premise” that Hetero’s claim
construction position “excludes salts and limits claim 1 to
the ‘free base’ form.” Instead, Hetero contends that its ar-
gument is simply that the weight-to-weight ratio limitation
compares the weights of the active moiety components of
dextromethorphan and quinidine, not their salt weights.
But there is no textual support for that argument. Claim
1 refers throughout to “dextromethorphan” and “quini-
dine,” so under Hetero’s theory, those terms either must
have a different meaning in the ratio limitation of claim 1
than elsewhere in the claims—a position Hetero does not
advance, and that would not be plausible in any event, see
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B
The specification provides additional support for
Otsuka’s construction. Several references to “dextrome-
thorphan” and “quinidine” in the specification point away
from Hetero’s construction requiring the weight-to-weight
ratio in claim 1 to be calculated using only the weight of
the free base forms of those compounds, even when the
compounds are administered in salt form.
Not only does the specification include express lan-
guage indicating that the references to dextromethorphan
and quinidine include the salt forms of those compounds,
but it specifically defines the active ingredients as includ-
ing not only the free base forms of dextromethorphan and
quinidine, but also their salt forms. See ’282 patent, col. 3,
ll. 21–23; col. 4, ll. 23–25; col. 5, ll. 22–25; col. 6, ll. 19–21
(stating, with respect to all 16 embodiments, that “the
quinidine includes quinidine sulfate and the dextrome-
thorphan includes dextromethorphan hydrobromide”).
The specification notes that the invention includes “dextro-
methorphan in combination with quinidine, or pharmaceu-
tically acceptable salts of dextromethorphan and/or
quinidine, as the active ingredient.” Id. at col. 17, ll. 32–
35.2
Phillips, 415 F.3d at 1314—or the terms “dextrome-
thorphan” and “quinidine” must refer to the free base form
of those compounds throughout the claims.
2 The dissent points out that the specification provides
chemical structures for “dextromethorphan” and “quini-
dine,” which depict the free base forms of those compounds.
However, the specification’s later use of those terms to in-
clude the salt forms indicates that the depicted structures
were not intended to suggest that the terms “dextrome-
thorphan” and “quinidine” in the patent refer exclusively
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In discussing a series of clinical studies conducted to
test the performance of the claimed formulations, the spec-
ification uses the terms “dextromethorphan” and “quini-
dine” to refer to both the free base and the salt forms of
those compounds, and frequently as a shorthand for the re-
spective salt forms of the compounds.
In Clinical Study #3, for example, participants were
given capsules with varying dosages of dextromethorphan
hydrobromide and quinidine sulfate. ’282 patent, col. 25,
ll. 31–65. In describing the results of that study, the quan-
tity of the salts that the participants received is referred to
as a “dose of dextromethorphan” and “quinidine doses,”
even though the amounts of those doses referred to the
amounts of the salts given to the participants in Clinical
Study #3, not the amount of the active moiety components
of those salts. E.g., id. at col. 28, line 7; col. 33, ll. 1–3. That
is, the dose of “dextromethorphan” and “quinidine” de-
scribed in the study is the amount of those compounds that
was administered in salt form in the capsules.
In Clinical Study #3, the specification refers to the ad-
ministration of dextromethorphan and quinidine in doses
of 30 mg, 45 mg, and 60 mg. Although the specification
notes that those doses were administered in the form of
dextromethorphan hydrobromide and quinidine sulfate,
the specification repeatedly describes those doses as “dex-
tromethorphan” and “quinidine.” See, e.g., id. at col. 25, ll.
12–18, 31–65; col. 26, ll. 39–40 (referring to “60 mg and 45
mg dextromethorphan doses”); col. 29, ll. 17–19 (referring
to “a 60 mg dose of dextromethorphan”); col. 33, ll. 1–3
(same); col. 34, ll. 12–14; col. 35, ll. 14–15 (referring to “the
effect of quinidine doses on a 45 mg dose of
to the free base forms of those compounds. See ’282 patent,
col. 9, ll. 22–34; col. 14, ll. 8–23.
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dextromethorphan”); col. 36, ll. 14–15 (referring to “a 60 mg
dose of dextromethorphan”); col. 38, ll. 17–18 (same).
At the conclusion of the discussion of Clinical Study #3,
the specification summarizes the results of that study by
stating that “the lowest effective dose of quinidine that in-
hibits the metabolism of 45 and 60 mg dextromethorphan
is 30 mg. Thus, a 30 mg quinidine dose is recommended
for dextromethorphan.” Id. at col. 40, ll. 52–67. That 30
mg quinidine dose clearly refers to the 30 mg of quinidine
sulfate that was administered to some subjects of Clinical
Study #3 who were given 45 and 60 mg of dextrome-
thorphan (in the form of dextromethorphan hydrobromide).
See id. at col. 25, ll. 36–39, 49–52. In light of the statement
in the specification that 30 mg of quinidine sulfate provides
an “effective dose” of 30 mg of quinidine, it is reasonable to
read the limitation in claim 1 requiring a range of “about
10 mg/day to less than about 30 mg/day” of quinidine as
referring to the amount of the quinidine compound as ad-
ministered, whether in its salt form or in its free base form.
Beyond that, the specification uses the abbreviation
DM to refer to dextromethorphan, see ’282 patent, col. 8, ll.
12–13, and the abbreviation Q to refer to quinidine, id. at
col. 8, ll. 27, 30. The specification then repeatedly uses
those terms to refer to the salt forms of both compounds.
In Clinical Study #5, the specification reports that partici-
pants were given “capsules containing dextromethorphan
hydrobromide and quinidine sulfate (DM/Q).” Id. at col. 54,
ll. 12–13. Participants “received capsules containing 30 mg
DM/30 mg Q or 15 mg DM/30 mg Q in increasing dosages.”
Id. at col. 55, ll. 18–19. Table 38, which contains a list of
the contents of the capsules, indicates that participants
were given capsules containing dextromethorphan hydro-
bromide monohydrate and quinidine sulfate dihydrate,
which are labeled in the table as “DM” and “Q.” Id. at col.
55, ll. 25–42.
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Table 38 includes notes indicating that 31.50 mg of the
monohydrate form of dextromethorphan hydrobromide is
equivalent to 30.0 mg of dextromethorphan hydrobromide.
’282 patent, col. 55, line 39. Likewise, the table reports
that 31.40 mg of the dihydrate form of quinidine sulfate is
equivalent to 30.0 mg of quinidine sulfate. Id. at col. 55,
line 41. No such note is listed to convert dextrome-
thorphan’s salt form to its free base form (dextrome-
thorphan hydrobromide to dextromethorphan). Nor is
there a note explaining any need to convert quinidine sul-
fate to quinidine. More significantly, the reference to “30
mg DM/30 mg Q or 15 mg DM/30 mg Q” matches the
amount of dextromethorphan hydrobromide and quinidine
sulfate in the capsules, thus making clear that the patent-
ees were using the quantity of the salt forms to refer to the
amounts of dextromethorphan and quinidine in the dos-
ages.3 See id. at col. 55, ll. 18–19.
C
The prosecution history also supports Otsuka’s pro-
posed construction, as it indicates that the examiner un-
derstood that the references in the claims to
dextromethorphan and quinidine included the salt forms of
those two compounds. When analyzing the original claims
of the application, the examiner referred to claims 1
through 10 as comprising “the administration of from
about 20 mg/day to about 200 mg/day of dextromethorphan
or dextromethorphan hydrobromide in combination with
about 10 mg/day to less than about 50 mg/day of quinidine
or quinidine sulfate.” Patent Application No. 11/035,213 at
3 The results of Clinical Study #4 follow a similar
pattern referring to the dosages as “30DM/30Q, or 30 mg
DM, or 30 mg Q” but listing the dosages as containing 31.50
mg of “DM,” or dextromethorphan hydrobromide monohy-
drate, and 31.40 mg of “Q,” or quinidine sulfate dihydrate.
’282 patent, col. 42, ll. 1–19.
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6 (Oct. 3, 2008) (Non-Final Rejection). The examiner sub-
sequently used the same characterization of identical lan-
guage in a co-pending application. J.A. 972–73 (citing
Patent Application No. 12/181,962 at 88–89 (July 29, 2008)
(Claims)) (Final Rejection). Those comments make it clear
that the examiner shared Otsuka’s understanding of the
terms “dextromethorphan” and “quinidine” in the applica-
tion that became the ’282 patent to include the salt forms
of those compounds.
We disagree with the dissent’s characterization of the
examiner’s statement in allowing the claims as indicating
that as of that time the applicants and the examiner un-
derstood the terms “dextromethorphan” and “quinidine” to
refer to the free base forms of those two compounds. Im-
mediately after discussing the weight-to-weight ratio of the
compounds, the examiner referred to declarations submit-
ted by Otsuka, including a declaration by inventor Dr.
Laura E. Pope. J.A. 1034. The Pope declaration features
an exhibit in which dextromethorphan and quinidine are
abbreviated as “DM” and “Q,” J.A. 1018–19, and doses of
DM and Q are in the salt forms of dextromethorphan hy-
drobromide monohydrate and quinidine sulfate dihy-
drate—not the free base forms. J.A. 1020.
D
Extrinsic evidence also confirms Otsuka’s construction.
As noted, Nuedexta contains 20 mg of dextromethorphan
hydrobromide and 10 mg of quinidine sulfate. J.A. 861.
With Hetero’s conversion, the salts in Nuedexta contain
15.41 mg of dextromethorphan and 8.69 mg of quinidine.
That means that Otsuka’s Nuedexta formulation under
Hetero’s construction would fall outside the weight-to-
weight ratio of claim 1. It is highly improbable that Avanir
would have drafted or amended the ’282 patent claims in a
manner that would exclude the very product that the pa-
tent was intended to protect. See Osram GmbH v. Int’l
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Trade Comm’n, 505 F.3d 1351, 1358 (Fed. Cir. 2007).4 An
inadvertent exclusion of Nuedexta in a later amendment,
as suggested by the dissent, seems highly unlikely.
E
Hetero makes several arguments in support of its pro-
posed claim construction. First, Hetero argues that be-
cause the specification includes information as to the
amount of dextromethorphan and quinidine in 30 mg of
dextromethorphan hydrobromide and quinidine sulfate,
the terms “dextromethorphan” and “quinidine” in claim 1
must refer to the weight of the dextromethorphan and
quinidine components in each of those compounds, not the
weight of the salt forms. The specification notes that 30
mg of dextromethorphan hydrobromide provides an effec-
tive dose of approximately 22 mg of dextromethorphan, and
30 mg of quinidine sulfate provides an effective dose of ap-
proximately 25 mg of quinidine. ’282 patent, col. 17, line
60, through col. 18, line 2. That passage of the specifica-
tion, however, does not bear on the proper claim construc-
tion, because the claims do not refer to “an effective dose,”
or an “effective weight” under the dissent’s characteriza-
tion, of dextromethorphan or quinidine. See id. at col. 78,
4 Hetero seeks to distinguish Osram on two grounds:
(1) that Osram concerned excluding disclosed embodi-
ments, while in this case “none of the embodiments dis-
closes the claimed ranges or the 1:0.5 ratio”; and (2) that
unlike in Osram, Nuedexta was covered by a different pa-
tent, which has expired. Reply Br. 12. To the contrary, the
embodiments in this patent encompass the ranges claimed,
see, e.g., ’282 patent, col. 2, ll. 22–29, and expressly include
the 1:0.5 ratio, see id. at col. 15, ll. 22–34. And the entry
for Nuedexta in the FDA’s Approved Drug Products with
Therapeutic Equivalence Evaluations (known as “the Or-
ange Book”) notes that Nuedexta is covered by the patent
in suit in this case.
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ll. 1–41.5 The dissent contends that comparing the salt
forms distorts the compounds’ relative weights, but a
skilled artisan could just as easily use the conversion to
find the amount of salt required for a desired amount of the
active moiety. The drafter’s choice of weight comparison is
one way of defining the claim scope and is not contrary to
the purpose of the invention.
Hetero contends that to justify construing “dextrome-
thorphan” and “quinidine” in claim 1 to include the salts of
those compounds, the claim would need to include the
words “or a salt thereof,” or the equivalent. Following that
line of reasoning would suggest that the claim language
should include “an effective dosage of” to conform with Het-
ero’s construction. Claim 1 specifies neither. While the in-
clusion of such language would have removed all doubt, we
find the indications in the patent to be sufficient to support
the claim construction proposed by Otsuka and adopted by
the district court.
Next, Hetero points to the original claims, which in-
cluded a dependent claim, claim 9, with a range for quini-
dine sulfate of about 30 mg/day to 60 mg/day, exceeding the
independent claim’s upper limit of 50 mg/day of quinidine.
J.A. 955. Hetero asserts that the range in claim 1, the in-
dependent claim, must refer to the free base forms of quin-
idine and dextromethorphan because 60 mg of quinidine
sulfate is approximately equivalent to 50 mg of free base
5 Significantly, claim 1 of the provisional application
referred to a “therapeutically effective quantity of dextro-
methorphan in combination with a therapeutically effec-
tive quantity of quinidine,” but that language was omitted
from the non-provisional application, which supports an in-
ference that the applicants did not intend the terms “dex-
tromethorphan” and “quinidine” to be limited to the
therapeutically effective portions of those compounds, i.e.,
the active moiety components.
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15
quinidine. In the next amendment, however, the applicant
reduced the range of the quinidine sulfate in claim 9 to a
range of 10 mg/day to 30 mg/day. Patent Application No.
11/035,213 Amendment at 2–3 (Oct. 23, 2008) (Amend-
ments to the Claims). If the applicants intended the refer-
ence to quinidine in claim 1 to be limited to the free base
form, the lower limit of the amount of quinidine sulfate in
dependent claim 9 would be outside the range set in inde-
pendent claim 1 because the amount of free base quinidine
in 10 mg of quinidine sulfate is less than 10 mg. That out-
come would be contrary to the basic principle that a de-
pendent claim may not be broader than the claim from
which it depends. Moreover, as noted, the examiner clearly
did not draw the inference from the language of original
claim 9 on which Hetero relies, as she characterized the
reference to “quinidine” in claim 1 of the application as re-
ferring to “quinidine or quinidine sulfate.” Patent Applica-
tion No. 11/035,213 at 6 (Oct. 3, 2008) (Non-Final
Rejection). For those reasons, the portion of the prosecu-
tion history relating to original claim 9, which was ulti-
mately canceled in any event, does not provide the support
for Hetero’s proposed claim construction that Hetero as-
serts.6
Hetero relies (Br. 34–37) on the report of its expert, Dr.
Graham Buckton, who offered the opinion that a person of
skill in the art would understand the weight-to-weight ra-
tio in claim 1 of the ’282 patent to refer to the weights of
the active moiety in the drug administered to patients,
even if the drug was administered in salt form. See J.A.
635–42. Dr. Buckton stated that in his view the terms
“dextromethorphan” and “quinidine” would be understood
to refer to “the active drug compounds.” The problem with
6 Original claim 9 was canceled in the subsequent
amendment of July 7, 2009, which also added the weight-
to-weight ratio limitation to claim 1. See J.A. 983–84.
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his construction is that it requires that the terms “dextro-
methorphan” and “quinidine” be understood to refer to the
active drug compounds throughout the patent, a conclusion
that is inconsistent with much of the specification and per-
tinent portions of the prosecution history, as discussed
above. Dr. Buckton’s report thus constitutes extrinsic evi-
dence that is at odds with the intrinsic evidence in this
case; as such, we give greater weight to the intrinsic evi-
dence. See Phillips, 415 F.3d at 1317–18.
Hetero also argues that to adopt Otsuka’s construction
would render the asserted claims indefinite because of the
numerous possible salt and free base compound combina-
tions that would satisfy the claims under that construction.
In a specific pharmaceutical product, however, the dextro-
methorphan and quinidine, whether in free base or salt
form, will be administered in measurable amounts. Under
Otsuka’s construction, the calculation of the weight-to-
weight ratio would be straightforward and not indetermi-
nate. For a product containing salts of dextromethorphan
and quinidine, only the particular salts used in the product,
such as dextromethorphan hydrobromide and quinidine
sulfate, would be used to calculate the weight-to-weight ra-
tio. It is possible under Otsuka’s construction that a party
could find a combination of salt-to-salt or even salt-to-free-
base that falls outside the scope of the weight-to-weight ra-
tio limitation while remaining within the other claim limi-
tations. That possibility, however, does not lead to
indefiniteness, because there is still only one way to calcu-
late the weight-to-weight ratio regardless of the particular
combination chosen. A party could choose from a range of
pharmaceutically acceptable salts, but only the selected
salt or salts could be used to calculate the ratio for a par-
ticular formulation. In the end, as Otsuka points out (Br.
46), the claim language is not indefinite because it simply
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17
directs that “you measure the weight of the form that is
‘administered.’”7
As evidence that a salt-to-free-base conversion is re-
quired, Hetero points to the label for “Nuedexta 15 mg/9
mg hard capsules,” a product Otsuka sells in Europe. J.A.
1374. The composition information for that product states
that “[e]ach capsule contains dextromethorphan hydrobro-
mide monohydrate, equivalent to 15.41 mg dextrome-
thorphan and quinidine sulfate dihydrate, equivalent to
8.69 mg quinidine.” J.A. 1374. The use of the terms “dex-
tromethorphan” and “quinidine” in the European label as
a shorthand for the active moiety in the administered
drugs does not speak to the proper construction of the
terms “dextromethorphan” and “quinidine” in the ’282 pa-
tent.
Finally, Hetero argues that it was improper for the dis-
trict court to rely on the prior litigation involving the ’282
patent, in which the district court found that other generic
drug manufacturers had infringed the ’282 patent. See
Avanir Pharms., Inc. v. Actavis S. Atl. LLC, 36 F. Supp. 3d
475 (D. Del. 2014), aff'd sub nom. Avanir Pharms. Inc. v.
Par Pharm. Inc., 612 F. App'x 613 (Fed. Cir. 2015). Hetero
argues that the previous case has no bearing on this one
because (1) Hetero was not a party to the Avanir case, (2)
the defendants in Avanir stipulated to infringement, so the
7 By analogy, suppose a claim referred to two inter-
acting molecules, both of which had two enantiomers, and
the court concluded that the claim was broad enough to en-
compass both enantiomers of each of the two compounds.
The court’s construction would not render the claim indef-
inite, even though the claim, as construed, would be broad
enough to cover four possible combinations of the molecules
rather than one.
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court in Avanir was not required to address the claim con-
struction issues presented to the district court in this case,
and (3) the court in Avanir did not address indefiniteness.8
The court in this case, however, did not treat the decision
in Avanir as binding, but merely regarded it as “instruc-
tive.” The court relied on other reasons for finding that
Otsuka was likely to succeed on the merits. See J.A. 7.
F
Based principally on the guidance provided by the spec-
ification, we find Otsuka’s proposed claim construction
more persuasive than the construction offered by Hetero.
We construe the terms “dextromethorphan” and “quini-
dine” in the ’282 patent, including their use in the weight-
to-weight ratio of claim 1, to refer to the form in which
those compounds are administered. Applying that con-
struction, we hold that the district court did not err in find-
ing that Otsuka was likely to succeed in proving that
Hetero infringed the ’282 patent.
We have considered the other arguments raised by
Hetero in challenging the district court’s preliminary in-
junction order and find them unpersuasive. We therefore
conclude that the district court acted within its discretion
in granting a preliminary injunction in this case.
IV
According to Federal Rule of Civil Procedure 65(c), a
court “may issue a preliminary injunction . . . only if the
movant gives security in an amount that the court consid-
ers proper to pay the costs and damages sustained by any
8 Although the district court in the Avanir litigation
did not expressly address indefiniteness, the defendants in
that case raised indefiniteness as a ground for invalidating
the ’282 patent, and the district court nonetheless held the
patent not invalid. See 36 F. Supp. 3d at 510.
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party found to have been wrongfully enjoined or re-
strained.” The Third Circuit has recognized limited excep-
tions to the Rule 65(c) bond requirement, but has noted
that waiver is “so rare that the requirement is almost man-
datory.” Frank’s GMC Truck Ctr., Inc. v. Gen. Motors
Corp., 847 F.2d 100, 103 (3d Cir. 1988).
The Third Circuit has held that the bond requirement
may be waived if “there is no risk of monetary loss to the
defendant.” Id. (citing Sys. Operations, Inc. v. Sci. Games
Dev. Corp., 555 F.2d 1131, 1145–46 (3d Cir. 1977)). The
court has also held that the bond requirement may be
waived under circumstances such as those described in
Temple University v. White, 941 F.2d 201, 219–20 (3d Cir.
1991). That case explained that a court may excuse com-
pliance with the bond requirement “at least in non-com-
mercial cases . . . [upon] consider[ing] the possible loss to
the enjoined party together with the hardship that a bond
requirement would impose on the applicant.” Id. at 219
(quoting Crowley v. Local No. 82, Furniture & Piano Mov-
ing, 679 F.2d 978, 1000 (1st Cir. 1982), rev’d on other
grounds, 467 U.S. 526 (1984)). An exception to the bond
requirement may also apply in “suits to enforce important
federal rights or public interests, arising out of comprehen-
sive federal health and welfare statutes.” Id. at 220 (quot-
ing Crowley, 679 F.2d at 1000) (citation modified).
Applying the first Temple exception, the district court
found the risk to financial harm to Hetero “speculative at
best” and expressed concern regarding “a chilling effect on
access to justice” if a multi-million-dollar bond were re-
quired in this case. J.A. 31 (citation omitted). Thus, the
court waived the requirement for Otsuka to post security
under Rule 65(c). J.A. 32.
We are bound to follow the Third Circuit’s narrow ex-
ceptions to Rule 65(c). And the Third Circuit has “never
excused a [d]istrict [c]ourt from requiring a bond where an
injunction prevents commercial, money-making activities.”
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20
Zambelli, 592 F.3d at 426. Hetero’s attempt to enter the
market with its generic pharmaceutical product is clearly
a commercial, money-making activity. Accordingly, we va-
cate the Rule 65(c) bond waiver and remand the bond issue
to the district court for reconsideration.
On remand, the district court may exercise its discre-
tion in determining an appropriate amount to require as a
security in light of the limited time remaining before the
’282 patent expires. With regard to the district court’s con-
cern about imposing a large expense for a bond on the
plaintiffs, we note that under the Local Rules for the
United States District Court for the District of Delaware,
the “reasonable premiums or expenses paid on bonds or se-
curity stipulations shall be allowed” as taxable costs when
those amounts are “furnished by requirements of the law
or rule of Court . . . or where required to enable a party to
receive or preserve some right accorded the party in an ac-
tion or proceeding.” D. Del. R. 54.1(b)(10).
V
In summary, we affirm the district court’s grant of
Otsuka’s motion for a preliminary injunction. We vacate
and remand for reconsideration the district court’s decision
to waive the Rule 65(c) bond requirement.
AFFIRMED IN PART, VACATED IN PART, AND
REMANDED
COSTS
No costs.
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United States Court of Appeals
for the Federal Circuit
______________________
OTSUKA AMERICA PHARMACEUTICAL, INC.,
AVANIR PHARMACEUTICALS, LLC, FKA AVANIR
PHARMACEUTICALS INC.,
Plaintiffs-Appellees
v.
HETERO LABS LIMITED, HETERO LABS LIMITED
UNIT-III, CAMBER PHARMACEUTICALS INC.,
Defendants-Appellants
______________________
2025-2016
______________________
Appeal from the United States District Court for the
District of Delaware in No. 1:25-cv-00647-GBW, Judge
Gregory Brian Williams.
______________________
D YK, Circuit Judge, dissenting-in-part and concurring-in-
part.
I respectfully dissent from the majority’s claim con-
struction, its conclusion on infringement, and its decision
sustaining the preliminary injunction.1
1 I join the majority’s opinion as to the district court’s
erroneous waiver of the bond requirement.
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2
The question is what the terms “dextromethorphan”
and “quinidine” mean in the claims of the ’282 patent. The
majority concludes that they refer to both (1) those mole-
cules alone, and (2) a broader class of salt compounds that
contain those molecules as active moieties and also a car-
rier ion that has no therapeutic significance. While admin-
istration via salt forms is covered by the claims because the
salt forms contain quinidine and dextromethorphan as ac-
tive moieties, the claimed weight measurements are de-
signed to only take into account the weight of those active
moieties, that is, the quinidine or dextromethorphan ions
contained within the salt compound. The majority’s con-
struction, which calculates the weight-to-weight ratio ei-
ther using the weight of the active moiety (when
administered in the pure “free base” form) or the total
weight of a salt compound (when administered in the salt
form), is inconsistent with the objective of the invention
and is unsupported by the specification and prosecution
history.
I
The ’282 patent covers methods for administering dex-
tromethorphan in combination with quinidine to treat emo-
tional lability, a neurological disorder. Independent
claim 1 is representative and recites:
A method for treating pseudobulbar affect or emo-
tional lability, the method comprising administer-
ing to a patient in need thereof dextromethorphan
in combination with quinidine, wherein the
amount of dextromethorphan administered com-
prises from about 20 mg/day to about 80 mg/day
and wherein the amount of quinidine administered
comprises from about 10 mg/day to less than about
30 mg/day with the proviso that the weight to
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3
weight ratio of dextromethorphan to quinidine is
1:0.5 or less.2
’282 patent, claim 1 (emphasis added).
The specification of the ’282 patent identifies two key
pieces of prior art, U.S. Patent No. 5,166,207 (the “’207 pa-
tent”) and U.S. Patent No. 5,206,248 (the “’248 patent”).
’282 patent, col. 14 ll. 28–30. These patents disclosed the
combined use of dextromethorphan and quinidine to treat
emotional lability. Dextromethorphan provides the neuro-
logical effect and quinidine “reduces the degradation of
dextromethorphan . . . which therefore increases dextro-
methorphan concentrations in the blood.” ’248 patent,
col. 2 ll. 56–61. When dextromethorphan was adminis-
tered on its own, it resulted in “extremely low [blood]
plasma levels of dextromethorphan or levels which were
less than 5 ng/ml” because of the fast metabolism of the
molecule in the body. ’207 patent, col. 5 ll. 59–63. How-
ever, when administered with quinidine, dextrome-
thorphan levels in the blood plasma “ranged from 28–
46 ng/ml,” even with a lower dose of dextromethorphan be-
cause the quinidine prevented that metabolization. Id.
col. 5 ll. 63–67. At the same time, it was known that quin-
idine can cause undesirable side effects, so it was desired
to administer no more quinidine than necessary.
The purpose of the invention claimed in the ’282 patent
is thus to decrease the blood level of quinidine while main-
taining a therapeutically effective blood level of dextrome-
thorphan in a patient that is receiving this treatment. See
J.A. 985 (patentee describing the invention during prose-
cution as “low-dose quinidine formulations” that “resolve[]
FDA concerns about the safety and tolerability [of] previ-
ously tested high-dose quinidine formulations” (emphasis
2 It is undisputed that “or less” modifies the amount
of quinidine in the claimed ratio rather than the ratio itself.
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4
in original)); J.A. 1035 (examiner describing the claimed
invention as achieving “a [dextromethorphan] blood level
that is effective in the treatment of . . . emotional lability,”
while reducing the amount of quinidine administered).
The claimed invention has a weight-to-weight ratio “of
dextromethorphan to quinidine [being] 1:0.5 or less.”
’282 patent, claim 1. The claim terms “dextromethorphan”
and “quinidine,” which are measured and compared by
weight, must be construed in light of the purpose of the in-
vention. As we stated in Sequoia Technology, LLC v. Dell,
Inc., “[w]e have explained that a patent’s express purpose
of the invention ‘informs the proper construction of claim
terms.’” 66 F.4th 1317, 1326 (Fed. Cir. 2023) (quoting Ka-
ken Pharm. Co. v. Iancu, 952 F.3d 1346, 1352 (Fed. Cir.
2020)). See also Nevro Corp. v. Boston Sci. Corp., 955 F.3d
35, 44 (Fed. Cir. 2020) (noting the relevance of the “purpose
of the claimed invention” to claim construction).
Nothing in the intrinsic record indicates that adminis-
tering quinidine or dextromethorphan in the form of a salt
(as opposed to the free base form) has any therapeutic ef-
fect related to the efficacy of the combination or that it af-
fects the blood levels of dextromethorphan and quinidine.
As salts are ionic compounds, the chemical structure of
both dextromethorphan and quinidine remains the same in
a salt form as it would be in the free base form. When quin-
idine is administered as quinidine sulfate, its strength is
diluted because there is less quinidine for each gram of
quinidine sulfate than there is in each gram of free base
quinidine. See ’282 patent col. 17 l. 63–col. 18 l. 2. When
dextromethorphan is administered as dextromethorphan
hydrobromide, its strength is also diluted. See id. Meas-
uring salt weights (as opposed to the weight of just the ac-
tive moieties) distorts the relative measurement, changing
the weight-to-weight ratio of the active moieties, and
thereby changing the resulting levels of dextromethorphan
and quinidine in the blood.
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5
The purpose of the invention is to achieve reduced
blood levels of quinidine in relation to the amount of dex-
tromethorphan. It would defeat the aims of the claimed
invention to compare the weight of diluted dextrome-
thorphan with that of an undiluted quinidine, or vice versa.
Even if both are diluted by being administered as salts, the
salt forms are diluted in different proportions such that the
ratio of pure quinidine to pure dextromethorphan is
greater than if administered in the undiluted forms. Meas-
uring the salt compound as a whole instead of the active
moiety inherently results in different calculations of the ef-
fective components. Such a result is absurd because it is
contrary to the inventive purpose of achieving a lower blood
level of quinidine while maintaining a therapeutically sig-
nificant level of dextromethorphan. A skilled artisan could
not conclude this construction is correct, as the only expert
testimony supplied by the parties indicates. As Hetero’s
expert testified without rebuttal, “the various salt and hy-
drate forms are merely formulation tools to deliver the ac-
tive drug compounds so that those compounds
(dextromethorphan and quinidine) can provide the desired
activity in the human body” so “[t]o precisely calculate the
weight of the effective dosage of an active drug in a partic-
ular formulation, a [skilled artisan] would use the molecu-
lar weights of the active drugs and the form at issue.”
J.A. 630–31.
The majority offers no coherent theory as to how its
claim construction is consistent with the purpose of the
claimed invention and the patent’s concern with the pro-
portions of the active moieties administered. The majority
states:
The dissent contends that comparing the salt forms
distorts the compounds’ relative weights, but a
skilled artisan could just as easily use the conver-
sion to find the amount of salt required for a de-
sired amount of the active moiety. The drafter’s
choice of weight comparison is one way of defining
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6
the claim scope and is not contrary to the purpose
of the invention.
Op. at 14. This appears to suggest that a skilled artisan
would adjust the relative proportions of the active moieties
by adjusting the salt formulations to reflect the desired
amount of the active moieties in the salt forms. But this is
exactly why computing the weight ratio based on the active
moieties is the only meaningful comparison and why the
comparison of the salt formulation weights is not con-
sistent with the purpose of the invention.
II
The majority also ignores other compelling intrinsic
support for Hetero’s construction. Claim 1 indicates that it
is the weight of dextromethorphan and quinidine, regard-
less of the form of administration, that matters. Both
“quinidine” and “dextromethorphan” are unambiguous
terms that describe “very specific compound[s]” with “dis-
cernible chemical structure.” SmithKline Beecham Corp.
v. Apotex Corp., 403 F.3d 1331, 1339–40 (Fed. Cir. 2005).
If Otsuka wanted to claim doses based on the weights of
pharmaceutically acceptable salts, Otsuka “had the ability
to draft the claim that way but it did not.” Source Vaga-
bond Sys. Ltd. v. Hydrapak, Inc., 753 F.3d 1291, 1300
(Fed. Cir. 2014); see also Helmsderfer v. Bobrick Washroom
Equip., Inc., 527 F.3d 1379, 1383 (Fed. Cir. 2008) (“Courts
cannot rewrite claim language.”); Alnylam Pharms., Inc.
v. Moderna, Inc., 138 F.4th 1326, 1333 (Fed. Cir. 2025)
(“[T]he intrinsic evidence must ‘clearly set forth’ or ‘clearly
redefine’ a claim term so as to put one reasonably skilled
in the art on notice . . . .” (quoting Bell Atl. Network Servs.,
Inc. v. Covad Commc’ns Grp., Inc., 262 F.3d 1258, 1268
(Fed. Cir. 2001))).
The specification confirms that this plain reading of the
claims is the correct one. The specification explicitly de-
fines “dextromethorphan” and “quinidine” as specific mol-
ecules with specific atoms arranged in specific structures.
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OTSUKA AMERICA PHARMACEUTICAL , INC. v.
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7
’282 patent, col. 9 ll. 22–34; col. 14 ll. 8–23; see also Aller-
gan, Inc. v. Apotex Inc., 754 F.3d 952, 960 (Fed. Cir. 2014)
(recognizing a patent may define a compound with its
chemical structure). In the claims, the salt forms are de-
scribed using the same terminology (“dextromethorphan”
and “quinidine”), but the claimed weights refer to the
weight of the active moieties contained in the salt. The
specification provides instructions to convert the weights of
dextromethorphan hydrobromide and quinidine sulfate
(the salt forms) into “effective weights” reflecting only the
dextromethorphan and quinidine ions in those salt formu-
lations. Id. col. 17 l. 60–col. 18 l. 14. This conversion guid-
ance underscores the importance of understanding how
much quinidine and dextromethorphan are contained
within doses administered as salts.
In the disclosed clinical trials, patentee chose to refer
to doses that clearly contain specific amounts of quinidine
sulfate and dextromethorphan hydrobromide as “Q” and
“DM” or the “quinidine dose[]” or the “dose of dextrome-
thorphan,” Op. at 9–11 (quoting ’282 patent, col. 28 l. 7,
col.33 ll. 1–3, col. 54 ll. 12–13, col. 55 ll. 25–42). But noth-
ing indicates that this use of shorthand to refer to doses
that contain quinidine and dextromethorphan has any rel-
evance to the claim language.3
The majority’s reliance on other aspects of the specifi-
cation to support Otsuka’s construction is also misplaced.
3 The majority also argues that the specification fails
to provide conversion instructions to calculate the weight
of quinidine present in a sample of quinidine sulfate or the
weight of dextromethorphan present in a sample of dextro-
methorphan hydrobromide. Op. at 11. That is incorrect,
as the patent clearly teaches the conversion ratio for each,
’282 patent, col. 17 l. 60–col. 18 l. 14, something the major-
ity’s opinion later recognizes, Op. at 13–14.
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OTSUKA AMERICA PHARMACEUTICAL , INC. v.
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8
While the claims are read in light of the specification, as-
pects of the specification must be given less weight where
the intrinsic record shows they lack relevance. See Trs. of
Colum. Univ. in City of New York v. Symantec Corp.,
811 F.3d 1359, 1368 (Fed. Cir. 2016); see also Honeywell
Inc. v. Victor Co. of Japan, Ltd., 298 F.3d 1317, 1327
(Fed. Cir. 2002).
The specification and original claims were directed to a
broad range of dosing regimens but largely lacked any
weight ratio. When the examiner determined the original
claims were unpatentable as obvious, patentee was then
forced to disclaim much of the original scope and claim a
specific weight-to-weight ratio limitation to distinguish the
prior art. In developing the current iteration of the claims,
patentee relied on developments made in a study con-
ducted in 2004 and communications from the FDA in 2006,
both after the asserted priority date. The result of this mid-
prosecution pivot is a disconnect between the claimed in-
vention and aspects of the specification, which is also al-
most entirely populated by embodiments unclaimed under
either party’s construction of the asserted claims.
In this context, the majority’s reliance on quotes from
the specification that “with respect to all 16 embodi-
ments . . . ‘the quinidine includes quinidine sulfate and the
dextromethorphan includes dextromethorphan hydrobro-
mide’” is unpersuasive. Op. at 8 (quoting ’282 patent, col. 3
ll. 21–23). The majority excludes the latter part of the sen-
tence, which makes clear that the quoted statement is not
a general claim that references to “quinidine” and “dextro-
methorphan” always encompass the salt forms. E.g.,
’282 patent, col. 3 ll. 21–27 (“In aspects of the . . . embodi-
ments, the quinidine includes quinidine sulfate and the
dextromethorphan includes dextromethorphan hydrobro-
mide, and wherein an amount of quinidine sulfate admin-
istered includes from about 30 mg/day to 60 mg/day and
wherein an amount of dextromethorphan hydrobromide ad-
ministered includes from about 30 mg/day to about
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9
60 mg/day.”). The majority also ignores that to the extent
that the 16 described embodiments describe doses and
weight-to-weight ratios, they do not describe the claimed
doses and ratio in the asserted claims. Instead, they map
onto the dosages originally claimed, which were deter-
mined to be obvious and then disclaimed through amend-
ment.
The majority’s reliance on Osram GmbH v. Interna-
tional Trade Commission is similarly misplaced. Op. at
12–13 (citing 505 F.3d 1351, 1358 (Fed. Cir. 2007)). In that
case, the parties contested whether claim language refer-
ring to the “mean grain diameter” should calculate the
“mean” based on the number of grains or the volume.
Osram, 505 F.3d at 1355. After concluding that the speci-
fication indicated that a number-based average was the ap-
propriate measure, we noted that a volume-based measure
would exclude the product that the patents were designed
to cover, likening that situation to a patent that excludes a
preferred embodiment. Id. at 1357–58. However, here,
neither the preferred embodiments nor Otsuka’s product
are instructive. Patentee sought a patent with a broader
scope that would have undisputably covered its Nuedexta
product. It then had to give up much of that scope to avoid
an obviousness rejection. In light of the prosecution his-
tory, it is not unusual that Otsuka’s product, like the vast
majority of the described embodiments, now falls outside
the scope of the claims. This context undermines the rele-
vance of the product to construction of the claim terms.
III
The majority also incorrectly relies on a prosecution
statement made by the examiner describing the original
claims as claiming administration of “dextromethorphan or
dextromethorphan hydrobromide” and “quinidine or quini-
dine sulfate” to conclude that it is “clear that the examiner
shared Otsuka’s understanding of the terms.” Op. at 12
(quoting ’213 application at 6 (Oct. 3, 2008) (Non-Final
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OTSUKA AMERICA PHARMACEUTICAL , INC. v.
HETERO LABS LIMITED
10
Rejection)). That statement says nothing about the com-
putation of the weight-to-weight ratios and is merely an
imprecise summary of several claims that does not define
the scope of those claims, let alone the claims that were
actually granted.
When allowing the current version of the claims, the
examiner chose different terms and, without mentioning
the salt forms, described the claimed invention as simply
the administration of “dextromethorphan” and “quinidine.”
J.A. 1033. The examiner described the ’207 and ’248 pa-
tents as “[t]he closest prior art.” Id. Those patents in-
volved administering the molecules in the free base form,
but the examiner concluded that they “do not specifically
teach a weight to weight ratio of dextromethorphan to
quinidine of 1:0.5 or less.” J.A. 1034. Thus, the examiner
specifically noted the weight-to-weight ratio limitation in
the context of a ratio computed from the amounts of the
pure forms. Once the purpose of the invention became re-
ducing the amount of quinidine administered and the
weight-to-weight ratio became central to the claimed in-
vention, the examiner understood the limitations to be
based on the relative weight of the dextromethorphan and
quinidine molecules themselves, not the relative weight of
their salt forms.
Because, under the correct claim construction, Hetero
has raised a substantial question of noninfringement, I
would reverse the preliminary injunction. See Metalcraft
of Mayville, Inc. v. Toro Co., 848 F.3d 1358, 1364 (Fed. Cir.
2017). I respectfully dissent.
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