United States Court of Appeals 

for the Federal Circuit ______________________

HOSPIRA, INC.,

Plaintiff-Appellant

v.

FRESENIUS KABI USA, LLC,

Defendant-Appellee

______________________

2019-1329, 2019-1367

______________________

Appeals from the United States District Court for the 

Northern District of Illinois in Nos. 1:16-cv-00651, 1:17-cv07903, Judge Rebecca R. Pallmeyer.

______________________

Decided: January 9, 2020

______________________

ADAM G. UNIKOWSKY, Jenner & Block LLP, Washington, DC, argued for plaintiff-appellant. Also represented 

by BRADFORD PETER LYERLA, AARON A. BARLOW, YUSUF 

ESAT, REN-HOW HARN, SARA TONNIES HORTON, Chicago, IL. 

 IMRON T. ALY, Schiff Hardin LLP, Chicago, IL, argued 

for defendant-appellee. Also represented by KEVIN 

MICHAEL NELSON, JOEL M. WALLACE; AHMED M.T. RIAZ, 

New York, NY. 

 ______________________

Before LOURIE, DYK, and MOORE, Circuit Judges.
2 HOSPIRA, INC. v. FRESENIUS KABI USA, LLC

LOURIE, Circuit Judge.

Hospira Inc. (“Hospira”) appeals from the judgment of 

the United States District Court for the Northern District 

of Illinois that claim 6 of U.S. Patent 8,648,106 (“the ’106 

patent”) is invalid as obvious. Hospira, Inc. v. Fresenius 

Kabi USA, LLC, 343 F. Supp. 3d 823 (N.D. Ill. 2018) 

(“Opinion”). Because we find that the district court’s factual findings were not clearly erroneous and that those 

findings support a conclusion of obviousness, we affirm.

BACKGROUND

Hospira makes and sells dexmedetomidine products 

under the brand name Precedex, including a ready-to-use 

product known as Precedex Premix. Hospira owns a number of patents that cover its Precedex Premix product. 

Fresenius Kabi USA LLC (“Fresenius”) filed an Abbreviated New Drug Application (“ANDA”) seeking approval to 

enter the market with a generic ready-to-use dexmedetomidine product. Hospira sued for infringement of five 

patents and eventually dropped all but two claims, one of 

which was claim 6 of the ’106 patent.1 Fresenius stipulated 

to infringement of claim 6, and the district court held a 

bench trial on its validity.

I. Prior Art Dexmedetomidine

Dexmedetomidine is a chemical compound that is effective as a sedative. ’106 patent col. 1 ll. 36–37. Dexmedetomidine was first developed and patented by Farmos 

Yhtyma Oy (“Farmos”) in the 1980s. Farmos was issued 

U.S. Patent 4,910,214, which disclosed the dexmedetomidine compound and its use as a sedative.

 

1 The other asserted claim was claim 8 of U.S. Patent 

9,616,049, which the district court held would have been 

obvious and is not at issue in this appeal.
HOSPIRA, INC. v. FRESENIUS KABI USA, LLC 3

In 1989, Farmos submitted an Investigational New 

Drug application (“the Farmos IND”) to the U.S. Food and 

Drug Administration (“FDA”) seeking approval to begin 

safety testing dexmedetomidine formulations in humans. 

Farmos conducted at least two human safety studies using 

intravenous administration of 20 μg/mL dexmedetomidine 

hydrochloride but subsequently abandoned its safety testing after the studies showed adverse effects.

In 1994, Farmos’s successor granted Abbott Laboratories (Hospira’s predecessor-in-interest) an exclusive license 

to make, use, and sell dexmedetomidine for human use in 

the United States. In 1999, Abbott Laboratories received 

FDA approval to market a 100 μg/mL dexmedetomidine hydrochloride formulation known as “Precedex Concentrate.” 

Precedex Concentrate is supplied in 2 mL clear glass vials 

and 2 mL clear glass ampoules made from Type IA sulfurtreated glass sealed with coated rubber stoppers. The 

100 μg/mL concentration of Precedex Concentrate is too 

strong to be directly administered to patients, and thus the 

label provides instructions for diluting the drug to a concentration of 4 μg/mL before intravenous administration.

Dexmedetomidine is also available as a sedative for 

commercial veterinary use. In 2002, the European Medicines Evaluation Agency authorized use of a product called 

Dexdomitor, which is a ready-to-use 500 μg/mL formulation of dexmedetomidine hydrochloride. Dexdomitor is 

stored in a 10 mL glass vial sealed with a coated rubber 

stopper and has a two-year shelf life.

II. The ’106 Patent

The ’106 patent is entitled “Dexmedetomidine Premix 

Formulation” and is directed to pharmaceutical compositions comprising dexmedetomidine (or a pharmaceutically 

acceptable salt of dexmedetomidine) formulated as a liquid 

for parenteral administration to a patient, “wherein the 

composition is disposed within a sealed container as a premixture.” ’106 patent at Abstract; see also ’106 patent col. 
4 HOSPIRA, INC. v. FRESENIUS KABI USA, LLC

1 ll. 19–20 (“The present invention relates to patient-ready, 

premixed formulations of dexmedetomidine, or a pharmaceutically acceptable salt thereof . . . .”). The ’106 patent 

describes the alleged problems associated with prior art 

dexmedetomidine formulations that the patented invention was intended to solve:

To date, dexmedetomidine has been provided as a 

concentrate that must be diluted prior to administration to a patient. The requirement of a dilution step in the preparation of the 

dexmedetomidine formulation is associated with 

additional costs and inconvenience, as well as the 

risk of possible contamination or overdose due to 

human error. Thus, a dexmedetomidine formulation that avoids the expense, inconvenience, delay 

and risk of contamination or overdose would provide significant advantages over currently available concentrated formulations.

Id. col. 1 l. 61–col. 2 l. 3. 

To address the perceived shortcomings of the prior art, 

the ’106 patent states that its invention relates to “premixed pharmaceutical compositions of dexmedetomidine,

or a pharmaceutically acceptable salt thereof, that are formulated for administration to a patient, without the need 

to reconstitute or dilute the composition prior to administration.” Id. col. 2 ll. 7–11. The patent specifies that the 

invention can be formulated as a “ready to use” composition, which is a premixed dexmedetomidine composition 

that is “suitable for administration to a patient without dilution.” Id. col. 3 l. 66–col. 4 l. 2. 

Importantly, the ’106 patent states that “[t]he present 

invention is based in part on the discovery that dexmedetomidine prepared in a premixed formulation that does 

not require reconstitution or dilution prior to administration to a patient, remains stable and active after prolonged 

storage.” Id. col. 3 ll. 6–10 (emphasis added). The patent 
HOSPIRA, INC. v. FRESENIUS KABI USA, LLC 5

describes “stability studies” that were conducted to measure the loss in potency of the drug over time. Id. col. 13–

col. 25 (Examples 1, 2, 4, and 6, which describe studies of 

dexmedetomidine potency over time under different conditions). For instance, Example 1 describes a study of potency of a 4 μg/mL dexmedetomidine hydrochloride 

formulation over time when stored in different storage containers, and Example 4 describes testing under different 

stresses and concludes that “[u]nder oxidative conditions, 

the sample showed highest amount of degradation.” Id. col. 

17 ll. 25–26. 

In Example 5, the patent describes a process by which 

a 4 μg/mL dexmedetomidine hydrochloride formulation

“can be manufactured.” Id. col. 17 ll. 57–58. That example 

manufacturing process includes “[n]itrogen sparging . . . throughout the manufacturing process.” Id. col. 17 

ll. 60–62. At the conclusion of the process, “[a]n atmosphere of filtered nitrogen gas is maintained in the headspace of the surge bottle,” and “the headspace of the 

container is gassed with nitrogen to achieve not more than 

5% of oxygen in the headspace.” Id. col. 18 ll. 58–62.

Claim 1 is the only independent claim in the ’106 patent:

1. A ready to use liquid pharmaceutical composition for parenteral administration to a subject, 

comprising dexmedetomidine or a pharmaceutically acceptable salt thereof disposed within a 

sealed glass container, wherein the liquid pharmaceutical composition when stored in the glass container for at least five months exhibits no more 

than about 2% decrease in the concentration of dexmedetomidine.

Id. col. 26 ll. 18–24. Claim 6, which depends from 

claim 1, is the only claim at issue in this appeal:
6 HOSPIRA, INC. v. FRESENIUS KABI USA, LLC

6. The ready to use liquid pharmaceutical composition of claim 1, wherein the dexmedetomidine or 

pharmaceutically acceptable salt thereof is at a 

concentration of about 4 μg/mL.

Id. col. 26 ll. 41–43.

III. District Court Proceedings

The district court held a five-day bench trial on Fresenius’s defense that claim 6 of the ’106 patent is invalid as 

obvious over the prior art combinations of Precedex Concentrate in combination with the knowledge of a person of 

ordinary skill in the art and Precedex Concentrate in combination with Dexdomitor. After the parties submitted 

their post-trial briefs, the court issued its findings of fact 

and conclusions of law, holding that Fresenius had proven 

by clear and convincing evidence that claim 6 would have 

been obvious over the prior art.

The district court determined that “to prove that a 

claim covering multiple alternative embodiments is invalid, a defendant need only prove that one of the embodiments is invalid.” Opinion, 343 F. Supp. 3d at 845–46 

(citing In re Cuozzo Speed Techs., LLC, 793 F.3d 1268, 1281 

(Fed. Cir. 2015)). Thus, the court focused on one allegedly 

obvious embodiment of claim 6, namely, “a ready-to-use, 

sealed glass container—made from Type I glass and a 

coated rubber stopper—with 4 μg/mL dexmedetomidine 

HCl,” which the court referred to as the “4 μg/mL preferred 

embodiment.”2 The court found that the 4 μg/mL preferred 

embodiment was expressly taught by the prior art, and the 

 

2 For consistency, we will similarly refer to this embodiment as the “4 μg/mL preferred embodiment” herein. 
HOSPIRA, INC. v. FRESENIUS KABI USA, LLC 7

only dispute between the parties concerned the “about 2%” 

limitation in claim 6.3 Id. at 846.

Based on the evidence in the trial record, the district 

court found that Fresenius had proven the following facts 

by clear and convincing evidence:

All stability data in the record for 4 μg/mL dexmedetomidine HCl formulations stored in Type I glass 

vials, sealed with coated rubber stoppers, and 

stored at room temperature shows that there was 

“no more than about 2%” loss in concentration at 

five months.

The “about 2%” limitation of the ’106 Patent is inherent in a 4 μg/mL dexmedetomidine HCl formulation, stored in a Type I glass vial sealed with a 

coated rubber stopper, and stored at room temperature for five months.

Opinion, 343 F. Supp. 3d at 841. To reach those findings, 

the district court relied on fact and expert testimony regarding the stability data for more than 20 tested samples 

of 4 μg/mL dexmedetomidine hydrochloride in the record,4

all of which met the about 2% limitation. Id. at 846-47. 

The court also relied on the conclusion of Fresenius’s expert 

that the concentration of dexmedetomidine does not have 

an effect on its stability. The court rejected Hospira’s 

 

3 The “about 2%” limitation refers to the claim limitation that reads “wherein the liquid pharmaceutical composition when stored in the glass container for at least five 

months exhibits no more than about 2% decrease in the 

concentration of dexmedetomidine.” 

4 The samples included 18 batch configurations in 

the Precedex Premix New Drug Application (three vial 

sizes, each of which was analyzed in three upright and 

three inverted configurations) and three samples in Fresenius’s ANDA. Opinion, 343 F. Supp. 3d at 833, 836.
8 HOSPIRA, INC. v. FRESENIUS KABI USA, LLC

arguments regarding stability data from 20 μg/mL samples 

in the Farmos IND, finding that Fresenius’s expert’s analysis of that data was more reliable than that of Hospira’s 

expert. Id. at 849–50. Furthermore, the court noted that, 

although a district judge in Delaware had previously found 

(in a separate litigation brought by Hospira against a different defendant) that the about 2% limitation had not 

been proven to be inherent, that decision was based on a 

different record and was not binding in this case. Id. at 

850–51 (citing Hospira, Inc. v. Amneal Pharm. LLC, 285 F. 

Supp. 3d. 776, 800 (D. Del. 2018), aff’d, 748 F. App’x 1024 

(Fed. Cir. 2019)).

The district court then considered whether a person of 

ordinary skill would have had a reasonable expectation of 

success in achieving the about 2% limitation from combining the other limitations disclosed in the prior art. On that 

issue, the court found:

A [person of ordinary skill in the art] would have a 

considerable understanding of organic chemistry. 

Based on his or her understanding of the chemical 

properties of dexmedetomidine, a [person of ordinary skill in the art] would have expected it to be 

stable in room-temperature storage conditions for 

at least five months. 

Opinion, 343 F. Supp. 3d at 841. To reach that finding, the 

court relied on expert testimony that the chemical structure of dexmedetomidine would be “a rock stable molecule” 

under normal conditions based on its aromatic ring structure and lack of hydrolyzable and oxidizable groups. Id. at 

852. The court also relied on information in the Precedex 

Concentrate and Dexdomitor labels, which do not contain 

chemical stabilizers despite their low concentrations. And 

the court credited expert testimony that the about 2% limitation is consistent with standard industry expectations 

for drug stability. Moreover, the court rejected each of Hospira’s arguments, finding that Hospira had failed to show 
HOSPIRA, INC. v. FRESENIUS KABI USA, LLC 9

that a person of skill would have expected a lower concentration to reduce stability or that a person of skill would 

have expected oxidation to occur in the absence of nitrogen 

sparging. Id. at 854–57.

Based on its factual findings, the district court concluded that claim 6 of the ’106 patent is invalid as obvious 

and entered judgment in favor of Fresenius. Hospira appealed the court’s judgment. We have jurisdiction under 

28 U.S.C. § 1295(a)(1).

DISCUSSION

On appeal from a bench trial, we review a district 

court’s conclusions of law de novo and its findings of fact 

for clear error. Braintree Labs., Inc. v. Novel Labs., Inc., 

749 F.3d 1349, 1358 (Fed. Cir. 2014) (citing Brown & Williamson Tobacco Corp. v. Philip Morris Inc., 229 F.3d 1120, 

1123 (Fed. Cir. 2000)). “A factual finding is clearly erroneous when, despite some supporting evidence, we are left 

with a definite and firm conviction that the district court 

was in error.” Alcon Research Ltd. v. Barr Labs., Inc., 745 

F.3d 1180, 1186 (Fed. Cir. 2014) (citing Alza Corp. v. Mylan 

Labs., Inc., 464 F.3d 1286, 1289 (Fed. Cir. 2006)). “The 

burden of overcoming the district court’s factual findings 

is, as it should be, a heavy one.” Polaroid Corp. v. Eastman 

Kodak Co., 789 F.2d 1556, 1559 (Fed. Cir. 1986). “Where 

there are two permissible views of the evidence, the factfinder’s choice between them cannot be clearly erroneous.” 

Anderson v. Bessemer City, 470 U.S. 564, 574 (1985) (citing 

United States v. Yellow Cab Co., 338 U.S. 338, 342 (1949)).

Obviousness is a question of law based on underlying 

facts, including the scope and content of the prior art. See 

Kinetic Concepts, Inc. v. Smith & Nephew, Inc., 688 F.3d 

1342, 1360 (Fed. Cir. 2012). “The inherent teaching of a 

prior art reference is a question of fact.” Par Pharm. v. TWI 

Pharm., Inc., 773 F.3d 1186, 1194 (Fed. Cir. 2014) (citation 

omitted). When the prior art does not expressly disclose a 

claim limitation, “inherency may supply a missing claim 
10 HOSPIRA, INC. v. FRESENIUS KABI USA, LLC

limitation in an obviousness analysis.” Id. at 1194–95 (collecting cases). Inherency is established in the context of 

obviousness when “the limitation at issue necessarily must 

be present, or the natural result of the combination of elements explicitly disclosed by the prior art.” Id. at 1195–96.

In this appeal, Hospira challenges the district court’s 

conclusion that claim 6 of the ’106 patent is invalid as obvious based on the inherency of the “about 2%” limitation. 

First, Hospira argues that the district court incorrectly 

considered the inherency of the about 2% limitation in nonprior art embodiments rather than the allegedly obvious 

prior art combination. Second, Hospira argues that the 

court applied a lower “reasonable expectation of success 

standard” rather than the higher “necessarily present” 

standard to the inherency question. We address each of 

these arguments in turn.

I

We first consider Hospira’s argument that the district 

court erred in its application of the inherency doctrine by 

considering the inherent properties of non-prior art embodiments. Hospira argues that every tested sample of the 

4 μg/mL preferred embodiment in the record was either 

from Hospira’s NDA for Precedex Premix or from Fresenius’s ANDA for its ready-to-use product, none of which 

were in the prior art. Hospira’s primary contention is that 

each of those samples was manufactured using the particular manufacturing process described in Example 5 of the 

’106 patent, and thus the stability data from those samples 

cannot suffice to prove that all samples of the allegedly obvious combination—a formulation of the 4 μg/mL preferred 

embodiment which may or may not have been prepared using the manufacturing process of Example 5—would “necessarily” meet the about 2% limitation. 

Fresenius responds that the district court did not err 

in relying on the tested samples of the 4 μg/mL preferred 

embodiment in the record, and it is irrelevant for the 
HOSPIRA, INC. v. FRESENIUS KABI USA, LLC 11

inherency analysis whether or not those samples were 

prior art. Fresenius contends that Hospira’s argument 

that unclaimed manufacturing variables from Example 5 

distinguish the tested samples from the prior art is a new 

argument raised for the first time on appeal and is therefore improper, and in any event is unfounded.

As a threshold matter, we agree with Fresenius that 

the district court did not err in relying on data obtained 

after the priority date of the ’106 patent in its inherency 

analysis. Extrinsic evidence can be used to demonstrate 

what is “necessarily present” in a prior art embodiment 

even if the extrinsic evidence is not itself prior art. See 

Monsanto Tech. LLC v. E.I. DuPont de Nemours & Co., 

878 F.3d 1336, 1345 (Fed. Cir. 2018) (allowing “non-prior 

art data” to be used to support inherency); Schering Corp. 

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

2003) (finding that the prior art need not recognize the inherent property). Moreover, the work of the inventor or the 

patentee can be used as the evidence of inherency. See, e.g.,

Alcon Research, Ltd. v. Apotex Inc., 687 F.3d 1362, 1369 

(Fed. Cir. 2012) (analyzing inherency based on the disclosure of the “patent itself”); Telemac Cellular Corp. v. Topp 

Telecom, Inc., 247 F.3d 1316, 1327–28 (Fed. Cir. 2001) 

(finding that features were inherent “as evidenced by [the 

patentee]’s own documents”). The later evidence is not itself prior art; it only helps to elucidate what the prior art 

consisted of. Therefore, it was not legally incorrect for the 

district court to rely on non-prior art data from Hospira’s 

NDA and Fresenius’s ANDA as evidence of the inherent 

stability of the 4 μg/mL preferred embodiment.

Furthermore, we agree with Fresenius that the unclaimed manufacturing variables in Example 5 do not, as a 

matter of law, preclude a finding of inherency in this case. 

First, although Hospira faults the district court for looking 

only at samples prepared by the manufacturing process of 

Example 5, it is not entirely clear that Hospira actually argued below that the inherency analysis required stability 
12 HOSPIRA, INC. v. FRESENIUS KABI USA, LLC

data from samples prepared by manufacturing processes 

other than Example 5. But even assuming that Hospira 

preserved that argument by raising it to the district court, 

it is without merit. Claim 6 is directed to a composition of 

4 μg/mL dexmedetomidine disposed in a sealed glass container. ’106 patent col. 26 ll. 18–24, 41–43. Claim 6 is not 

a method claim, it is not a product-by-process claim, and 

there are no limitations in claim 6 regarding the manufacturing process by which the recited 4 μg/mL dexmedetomidine composition must be prepared. Importing such 

limitations from Example 5 into the claim, as Hospira 

seeks to do, would be improper. See Phillips v. AWH Corp., 

415 F.3d 1303, 1323 (Fed. Cir. 2005). Thus, the district 

court did not misapply the law of inherency by considering

the samples in the record without regard to the process by 

which those samples were prepared.

Because the district court did not legally err in applying the inherency doctrine, what remains for our review is 

the court’s factual finding that the about 2% limitation was 

necessarily present in the 4 μg/mL preferred embodiment. 

At trial, Fresenius presented evidence in support of its inherency contention. That evidence included data from 

more than 20 samples of the 4 μg/mL preferred embodiment, every one of which met the about 2% limitation. The 

evidence also included expert testimony that concentration 

does not affect the stability of dexmedetomidine, which 

demonstrates that dexmedetomidine is a very stable drug. 

The district court relied on that evidence to find that the 

about 2% limitation was necessarily present in the 4 μg/mL 

preferred embodiment in the prior art. 

Hospira disagrees with the factual findings of the district court. For example, Hospira asks us to find that the 

samples in the record are not representative of every possible formulation of the 4 μg/mL preferred embodiment. 

But Hospira did not present evidence of even a single sample of the 4 μg/mL preferred embodiment that failed to 

meet the about 2% limitation. Additionally, Hospira did 
HOSPIRA, INC. v. FRESENIUS KABI USA, LLC 13

not present evidence sufficient to persuade the district 

court that the manufacturing process of Example 5 was the 

reason why all tested samples met the about 2% limitation, 

or that samples prepared by a different process might not 

meet that limitation. See Acorda Therapeutics, Inc. v. Roxane Labs., Inc., 903 F.3d 1310, 1335–36 (Fed. Cir. 2018) 

(noting that the patent owner “cites no support” for the assumption that inherent properties would differ between 

the prior art and the claim).

Hospira also insists that the district court erred by not 

requiring Fresenius to present a quantitative drug loss 

model. But Hospira presented that factual contention at 

trial, and the court rejected it. The court instead credited 

the testimony of Fresenius’s expert that there was not 

enough drug loss to be able to discern one drug loss model 

from another. The court found that, “[i]f anything, the inability to assign a loss model to dexmedetomidine underscores Fresenius Kabi’s position that the 4 μg/mL preferred 

embodiment will necessarily experience no more than two 

percent loss in concentration at five months.” Opinion, 

343 F. Supp. 3d at 849. 

Hospira’s arguments on appeal cannot change the trial 

record, which included more than 20 samples that all met 

the about 2% limitation. The trial record also included testimonial and statistical evidence that dexmedetomidine is 

a very stable drug at any concentration; thus, simply adding solvent to dilute it by a factor of 25—from 100 μg/mL, 

which was known to be stable, to 4 μg/mL—does not affect 

its inherent stability. On that record, it was not clearly 

erroneous for the district court to find that the about 2% 

limitation was necessarily present in the prior art.

II

We turn to Hospira’s argument that the district court 

applied the wrong standard to the inherency question. 

Hospira argues that the district court applied the “reasonable expectation of success” standard in its inherency 
14 HOSPIRA, INC. v. FRESENIUS KABI USA, LLC

analysis of the chemical structure of dexmedetomidine. 

Thus, Hospira argues, the district court did not conduct a 

complete inherency analysis under the correct “necessarily 

present” standard.

Fresenius responds that the district court completed its 

inherency analysis when it found that the about 2% limitation was necessarily present in the prior art based on the 

evidence of the tested samples in the record. Fresenius argues that, after completing that correct analysis of inherency, the court then separately found that a person of 

ordinary skill would have had a reasonable expectation of 

success in achieving the about 2% limitation.

“An obviousness determination requires that a skilled 

artisan would have perceived a reasonable expectation of 

success in making the invention in light of the prior art.” 

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

1362 (Fed. Cir. 2009). In this appeal, the parties do not 

dispute that Fresenius met its burden of proof on that issue. See Appellant’s Br. 37 (“[T]he District Court found a 

reasonable expectation of success; although Hospira respectfully disagrees with the District Court’s conclusion on 

this issue, it acknowledges the deferential standard of review and does not contend that this finding is clearly erroneous.”). Thus, the only dispute is whether the district 

court’s inherency analysis was correct. We agree with 

Fresenius that it was.

As explained above, the district court engaged in a 

thorough and extensive analysis of the stability data in the 

record to reach its factual finding that the about 2% limitation was necessarily present in the prior art. Opinion, 

343 F. Supp. 3d at 841, 845–51. But the district court then 

engaged in unnecessary analysis in evaluating whether the 

chemical properties of the dexmedetomidine molecule, the 

information in the Precedex Concentrate and Dexdomitor 

labels, and the industry guidance for stability testing 

would enable a person of ordinary skill to have had a 
HOSPIRA, INC. v. FRESENIUS KABI USA, LLC 15

reasonable expectation of successfully achieving the about 

2% limitation. Id. at 851–57. The court thus conflated the 

standards for inherency and reasonable expectation of success. However, that was harmless error that did not infect 

its inherency analysis and findings. See Vanderbilt Univ.

v. ICOS Corp., 601 F.3d 1297, 1308 (Fed. Cir. 2010) (“The 

district court’s findings demonstrate that under the correct 

legal test, [the plaintiff] did not carry its burden. Thus, any 

erroneous interpretations of our case law were harmless 

error.”); see also Environ Prods. v. Furon Co., 215 F.3d 

1261, 1266 (Fed. Cir. 2000) (“When the error as to the 

weight of proof could not have changed the result, the erroneous instruction is harmless.” (citing 11 CHARLES ALAN 

WRIGHT & ARTHUR R. MILLER, FEDERAL PRACTICE AND 

PROCEDURE § 2886 (2d ed. 1995))). If a property of a composition is in fact inherent, there is no question of a reasonable expectation of success in achieving it. The claimed 

dexmedetomidine formulation already is, as the evidence 

in this case shows, possessed of the about 2% limitation. 

III

Having concluded that the district court’s factual findings were not clearly erroneous, we finally turn to the legal 

question of whether those findings support a conclusion 

that claim 6 would have been obvious. We conclude that 

they do.

It is well-settled that the inclusion of an inherent, but 

undisclosed, property of a composition does not render a 

claim to the composition nonobvious. Atlas Powder Co. v. 

Ireco Inc., 190 F.3d 1342, 1347 (Fed. Cir. 1999) (“[T]he discovery of a previously unappreciated property of a prior art 

composition, or of a scientific explanation for the prior art’s 

functioning, does not render the old composition patentably new to the discoverer.” (citing Titanium Metals Corp. v. 

Banner, 778 F.2d 775, 782 (Fed. Cir. 1985))). A patent can 

be invalid based on inherency when the patent itself makes 

clear that a limitation is “not an additional requirement 
16 HOSPIRA, INC. v. FRESENIUS KABI USA, LLC

imposed by the claims . . . , but rather a property necessarily present.” In re Kubin, 561 F.3d 1351, 1357 (Fed. Cir. 

2009); see also Persion Pharm. LLC v. Alvogen Malta Operations Ltd., Case No. 18-2361, slip op. at 13 (Fed. Cir. Dec. 

27, 2019) (“[T]he district court did not err by finding that 

the pharmacokinetic limitations of the asserted claims 

were inherent and added no patentable weight to the pharmacokinetic claims.”); Alcon Research, 687 F.3d at 1369 

(“[T]his claim language does not impose any additional requirement because the ’805 patent itself defines mast cell 

stabilization as a property that is necessarily present at 

those concentrations.”); In re Kao, 639 F.3d 1057, 1070

(Fed. Cir. 2011) (“Substantial evidence supports the 

Board’s finding, based upon the specification, which confirms that the claimed ‘food effect’ is an inherent property 

of oxymorphone itself . . . .”). 

Here, the ’106 patent itself states that the invention 

was based on “the discovery that dexmedetomidine prepared in a premixed formulation . . . remains stable and 

active after prolonged storage.” ’106 patent, col. 3 ll. 6–10 

(emphasis added). Claim 6 does not recite any manufacturing limitations that are related to stability or an added 

component that enhances stability; it simply recites a composition, with a “wherein” clause that describes the stability of that recited composition, a result that was inherent 

in the prior art.

In sum, the district court did not clearly err in finding 

as a factual matter that the about 2% limitation was necessarily present in the prior art, and as a legal matter the 

inclusion of the inherent about 2% limitation does not 

make claim 6 nonobvious. We therefore agree with the district court’s conclusion that claim 6 of the ’106 patent would 

have been obvious over the prior art.
HOSPIRA, INC. v. FRESENIUS KABI USA, LLC 17

CONCLUSION

We have considered Hospira’s remaining arguments, 

but we find them unpersuasive. Accordingly, the judgment 

of the district court is affirmed.

AFFIRMED