NOTE: This disposition is nonprecedential.

United States Court of Appeals 

for the Federal Circuit ______________________ 

APTALIS PHARMATECH, INC., IVAX 

INTERNATIONAL GMBH,

Plaintiffs-Appellees

v.

APOTEX INC., APOTEX CORP.,

Defendants-Appellants

______________________ 

2017-1344

______________________ 

Appeal from the United States District Court for the 

District of Delaware in No. 1:14-cv-01038-SLR-SRF, 

Judge Sue L. Robinson.

______________________ 

Decided: January 4, 2018

______________________ 

 JOHN R. LANE, Fish & Richardson, PC, Houston, TX, 

argued for plaintiffs-appellees. Also represented by 

SUSAN E. MORRISON, Wilmington, DE; JONATHAN ELLIOT 

SINGER, San Diego, CA.

 WILLIAM R. ZIMMERMAN, Knobbe, Martens, Olson & 

Bear, LLP, Washington, DC, argued for defendantsappellants. Also represented by THOMAS P. KRZEMINSKI;

KAREN MARIE CASSIDY, CRAIG S. SUMMERS, Irvine, CA.
2 APTALIS PHARMATECH, INC. v. APOTEX INC. 

______________________ 

Before REYNA, WALLACH, and STOLL, Circuit Judges.

STOLL, Circuit Judge. 

In this Hatch-Waxman case, Apotex Inc. and Apotex 

Corp. appeal from the district court’s claim construction of 

“extended release coating” and its finding that Apotex’s 

product infringes U.S. Patent Nos. 7,790,199 and 

7,829,121. We conclude that the district court erred by 

not construing the term “extended release coating” to 

require a continuous outer film, as taught by the intrinsic 

evidence. Accordingly, we vacate the infringement finding and remand for further proceedings.

I.

The goal of a drug delivery system is to achieve rapidly a therapeutically effective concentration of drug in the 

body and to maintain that concentration throughout the 

treatment period. When a patient swallows a tablet, 

gastrointestinal fluids dissolve the drug inside the tablet, 

and the drug is absorbed into the body. In an immediate 

release formulation, the majority of the drug dissolves 

within an hour because the tablet disintegrates once it is 

swallowed, and the body’s gastrointestinal fluids contact 

and dissolve the drug. Therefore, patients seeking continuous relief from their symptoms must take an immediate release formulation several times per day. 

An extended release formulation, as its name implies,

can sustain therapeutically effective drug concentrations

over a prolonged period by releasing the drug at a slower 

rate. These formulations employ controlled release materials that surround the drug and create a barrier through 

which gastrointestinal fluids must travel to access the 

drug, or “active” substance. The controlled release material decreases the rate at which gastrointestinal fluids 

penetrate the tablet to dissolve the drug and the rate at 
APTALIS PHARMATECH, INC. v. APOTEX INC. 3

which the dissolved drug escapes the tablet to be absorbed 

into the body. 

Aptalis Pharmatech, Inc. and Ivax International 

GmbH own the ’199 and ’121 patents (collectively, the 

“asserted patents”), which relate generally to extended 

release dosage forms of cyclobenzaprine hydrochloride, a 

skeletal muscle relaxant.1 Instead of requiring three 

daily doses of cyclobenzaprine, as in the prior art, the 

asserted patents disclose an extended release cyclobenzaprine formulation that provides twenty-four hour relief 

from muscle spasms with a single dose. 

The asserted patents teach two different formulations

that use a water insoluble polymer coating to achieve an 

extended release profile. The parties refer to these alternatives as membrane systems and matrix systems. In a 

membrane system, a water insoluble polymer coating is 

applied onto an active-containing core:

The active core of the dosage form of the present

invention may comprise an inert particle such as 

a sugar sphere, or an acidic or alkaline buffer 

crystal, which is coated with a skeletal muscle relaxant such as cyclobenzaprine . . . . The drug 

layered beads may be coated with a protective 

seal coating of OPADRY® Clear to produce IR 

[immediate release] Beads. . . . 

ER [extended release] Beads can be produced 

by applying a functional membrane comprising a 

water insoluble polymer alone or in combination 

with a water soluble polymer onto IR Beads.

1 The asserted patents share a common specification, and unless otherwise noted, all citations are to the 

’199 patent.

 
4 APTALIS PHARMATECH, INC. v. APOTEX INC. 

’199 patent col. 3 l. 67 – col. 4 l. 17. In a matrix system, 

the water insoluble polymer is mixed together with the 

drug and compacted into a tablet:

[T]he drug substance, optionally a binder such as 

PVP, a dissolution rate controlling polymer (if 

used), and optionally other pharmaceutically acceptable excipients are blended together in a 

planetary mixer or a high shear granulator such 

as Fielder and granulated by adding/spraying a 

granulating fluid such as water or alcohol. The 

wet mass can be extruded and spheronized to 

produce spherical particles (beads) using an extruder/marumerizer.

Id. at col. 6 ll. 23–31. 

Although the specification discloses two different extended release formulations, the claims are not expressly

limited to a specific formulation by name (i.e., “membrane

system” or “matrix system”), as demonstrated by representative claim 1: 

1. A pharmaceutical dosage form comprising 

a population of extended release beads, wherein 

said extended release beads comprise:

an active-containing core particle comprising 

cyclobenzaprine hydrochloride as the active; and

an extended release coating comprising a water insoluble polymer membrane surrounding said 

core, wherein said water insoluble polymer membrane comprises a polymer selected from the 

group consisting of ethers of cellulose, esters of 

cellulose, cellulose acetate, ethyl cellulose, polyvinyl acetate, neutral copolymers based on ethyl 

acrylate and methyl methacrylate, copolymers of 

acrylic and methacrylic acid esters with quaternary ammonium groups, pH-insensitive ammonio 
APTALIS PHARMATECH, INC. v. APOTEX INC. 5

methacrylic acid copolymers, and mixtures thereof;

wherein the total amount of cyclobenzaprine 

hydrochloride in the pharmaceutical dosage form 

is 30 mg;

wherein following a single oral administration 

of the pharmaceutical dosage form, the pharmaceutical dosage form provides a maximum blood 

plasma concentration (Cmax) of 19.851±5.8765 

ng/mL of cyclobenzaprine HCl and an AUC0-168 of 

736.60±259.414 ng·hr/mL.

Id. at col. 10 ll. 23–45 (emphasis added). 

 After Apotex filed an Abbreviated New Drug Application seeking to produce and market a generic version of 

AMRIX®,2 Aptalis sued Apotex for infringing claims 1, 2, 

and 5 of the ’199 patent, as well as claims 14, 16, and 17 

of the ’121 patent. Apotex argued that it does not infringe 

because its products contain a matrix-style formulation.

The parties’ dispute centers on the construction of “an 

extended release coating comprising a water insoluble 

polymer membrane surrounding said core,” which is found 

in every asserted claim. Before the district court issued 

its claim construction order, the parties stipulated to a 

construction for part of the disputed term. They agreed 

that “a water insoluble polymer membrane surrounding 

said core” means “a water insoluble polymer covering that 

surrounds the active core.” J.A. 1619. The district court 

subsequently construed “extended release coating,” the 

remainder of the disputed claim term, as “[a] layer of any 

2 The asserted patents are listed in the FDA’s Approved Drug Products with Therapeutic Equivalence 

Evaluations for Aptalis’ AMRIX® extended release product. 

 
6 APTALIS PHARMATECH, INC. v. APOTEX INC. 

substance that is applied onto the surface of another, the 

purpose of which is to delay the release of a drug in order 

to maintain the drug at therapeutically effective concentrations over an extended period of time.” J.A. 23. Applying this claim construction, the district court found that 

Apotex’s ANDA product contained an extended release 

coating and infringed the asserted claims of the ’199 and 

’121 patents. Aptalis Pharmatech, Inc. v. Apotex Inc., 

220 F. Supp. 3d 544, 550–55 (D. Del. 2016) (“Dist. Ct. 

Op.”). 

Apotex appealed the district court’s claim construction 

and its infringement finding. We have jurisdiction pursuant to 28 U.S.C. § 1295(a)(1). 

II.

Claim construction seeks to ascribe the “ordinary and 

customary meaning” to claim terms as a person of ordinary skill in the art would have understood them at the 

time of invention. Phillips v. AWH Corp., 415 F.3d 1303, 

1312–14 (Fed. Cir. 2005) (en banc) (citing Vitronics Corp. 

v. Conceptronic, Inc., 90 F.3d 1576, 1582 (Fed. Cir. 1996)). 

“Where the district court’s claim construction relies only 

on intrinsic evidence, the construction is a legal determination reviewed de novo.” Ruckus Wireless, Inc. v. Innovative Wireless Sols., LLC, 824 F.3d 999, 1002 (Fed. Cir. 

2016) (citing Teva Pharm. USA, Inc. v. Sandoz, Inc., 

135 S. Ct. 831, 841 (2015)). 

When construing claims, “there is sometimes a fine 

line between reading a claim in light of the specification, 

and reading a limitation into the claim from the specification.” Comark Commc’ns, Inc. v. Harris Corp., 156 F.3d 

1182, 1186 (Fed. Cir. 1998). This case tiptoes that line. 

The specification does not provide a lexicographic definition of “coating,” and the prosecution history contains no 

clear and unmistakable disavowal of claim scope. Nonetheless, Apotex contends that the intrinsic evidence would 

have taught an ordinarily skilled artisan at the time of 
APTALIS PHARMATECH, INC. v. APOTEX INC. 7

the invention that an “extended release coating” is limited 

to a continuous outer film, not simply “[a] layer of any 

substance that is applied onto the surface of another.” 

For the reasons explained below, we agree and adopt 

Apotex’s proposed construction of “extended release 

coating” as “a continuous outer film applied onto the 

surface of the active-containing core to provide an extended release of the active core.” See Appellants Br. 21. 

We begin, as we must, with the plain claim language. 

Phillips, 415 F.3d at 1312 (“[T]he claims are ‘of primary 

importance[] in the effort to ascertain precisely what it is 

that is patented.’” (quoting Merrill v. Yeomans, 94 U.S. 

568, 570 (1876)). Here, the claim language recites an 

“extended release coating comprising a water insoluble 

polymer membrane surrounding said [active-containing]

core.” ’199 patent col. 10 ll. 28–29 (emphases added). It is

clear that the coating must surround the core. As the 

district court recognized, dictionaries define “surround” as 

“to enclose on all sides.” Dist. Ct. Op., 220 F. Supp. 3d at 

548 n.10.3 A coating that surrounds the core or encloses it

on all sides connotes a continuous coating, i.e., one that 

covers the entire surface of the core. And, because the 

extended release coating must surround the core, the 

plain claim language suggests that the coating must be 

located outside of the core. In other words, the water 

insoluble polymer membrane is an outer coating relative 

to the core. Our construction reflects these limitations by 

requiring a “continuous outer film applied onto the surface of the active-containing core.”

3 The parties do not dispute that “surrounding,” as 

used in the ’199 patent, means “to enclose on all sides”; 

instead, they dispute whether “surround” means that the 

coating must be “continuous.” See Appellants Br. 22; 

Appellees Br. 39.

 
8 APTALIS PHARMATECH, INC. v. APOTEX INC. 

The specification bolsters our conclusion that the extended release coating must be a continuous outer film. 

See Phillips, 415 F.3d at 1315 (“[T]he specification ‘is 

always highly relevant to the claim construction analysis.’” (internal citation omitted)). First, every embodiment 

in the specification that discusses a coating describes a 

process in which the water insoluble polymer coating is 

external to the active-containing core. See, e.g., ’199 

patent col. 4 ll. 15–17 (“ER Beads can be produced by 

applying a functional membrane comprising a water 

insoluble polymer alone or in combination with a water 

soluble polymer onto IR Beads.”); id. at col. 5 ll. 38–41 

(“The [active]-containing particle may be coated with an 

extended release (ER) coating comprising a water insoluble polymer or a combination of a water insoluble polymer 

and a water soluble polymer to provide ER beads.”); id. at 

col. 4 ll. 33–36 (“ER beads include a core particle (IR 

(immediate release) bead) containing a skeletal muscle 

relaxant and an ER (extended release) coating comprising 

a water insoluble polymer surrounding the core.”); id. at 

col. 5 ll. 60–64 (describing process of “coating the IR bead 

with a plasticized water-insoluble polymer alone such as 

ethylcellulose or in combination with a water soluble 

polymer such as hydroxypropylmethylcellulose to form an 

Extended Release (ER) bead”); id. at col. 7 ll. 32–35 (disclosing the step of “coating the active drug particle with a 

solution or suspension of a water insoluble polymer or a 

mixture of water soluble and water insoluble polymers to 

form an extended release coated drug particle (ER 

beads)”). The same is true for Example 2, which describes 

spraying an extended release polymer membrane “onto 

the IR beads for a weight gain of approximately 10%.” Id.

at col. 8 ll. 39–43; see id. at col. 8 l. 62 – col. 9 l. 13 (discussing Example 3’s application of extended release 

coating onto immediate release beads until a certain 

weight gain is reached). 
APTALIS PHARMATECH, INC. v. APOTEX INC. 9

These disclosures would have taught a person of ordinary skill that the extended release coating is an outer 

coating of polymer relative to the active-containing core.4 

And the specification’s frequent references to applying the 

extended release coating “onto” the active-containing core 

comports with our understanding of the spatial orientation required by the claims. See, e.g., id. at col. 3 ll. 64–

67, col. 4 ll. 15–17, col. 8 ll. 39–43, col. 8 ll. 62–66. 

Second, the specification demonstrates the inventors’ 

ability to describe a non-continuous coating when they so 

desired. The specification’s background of the invention 

4 The specification’s disclosure of an extended release matrix formulation does give us pause. See id. at 

col. 6 ll. 23–33 (describing an embodiment where the ratecontrolling polymer is blended together with the active 

drug and compressed into beads, as opposed to spraying 

the rate controlling polymer onto an active-containing 

core). But while a construction that excludes a preferred 

embodiment “is rarely, if ever, correct,” Vitronics Corp., 

90 F.3d at 1583, “[t]his does not mean . . . that each and 

every claim ought to be interpreted to cover each and 

every embodiment,” PPC Broadband, Inc. v. Corning 

Optical Commc’ns RF, LLC, 815 F.3d 747, 755 (Fed. Cir. 

2016). We note that the specification describes the steps 

in this embodiment as “blend[ing],” “granulat[ing],” 

“extrud[ing],” and “spheroniz[ing].” Id. at col. 6 ll. 26–30. 

The other embodiments and the claims, however, require

a “coating”; and, in any event, nothing in the specification 

forbids the application of an extended release coating onto 

this matrix embodiment. See Oral Arg. at 28:44–30:29, 

http://oralarguments.cafc.uscourts.gov/default.aspx?fl=20

17-1344.mp3. Thus, this does not alter our conclusion 

that the specification, when read as a whole, would have 

taught an ordinarily skilled artisan that an “extended 

release coating” requires a continuous outer film.

 
10 APTALIS PHARMATECH, INC. v. APOTEX INC. 

section referred to a prior art reference that disclosed the 

application of a water impermeable coating onto a core

followed by the creation of apertures in the coating. The 

inventors of the asserted patents described the coating in 

this prior art reference as “ha[ving] apertures exposing 

between about 5–75% of the core surface.” Id. at col. 2 

ll. 30–31. By contrast, the asserted claims require the 

coating to “surround[] said core.” The inventors’ decision 

to claim a coating that surrounds the core instead of 

claiming a coating with a certain percentage of exposed 

core surface would have informed a person of ordinary 

skill in the art that the claims require a continuous

coating. 

The prosecution history offers additional support for 

construing “extended release coating” to require a continuous outer film. See Markman v. Westview Instruments, 

Inc., 52 F.3d 967, 980 (Fed. Cir. 1995) (en banc) (“To 

construe claim language, the court should also consider 

the patent’s prosecution history, if it is in evidence.”). 

During prosecution of the ’199 patent, the applicants 

submitted a declaration from Dr. James W. McGinity. 

The Declaration summarizes Dr. McGinity’s interview 

with the examiner during the prosecution of a related 

patent application that shares the same specification as 

the asserted patents. According to Dr. McGinity, the 

process taught by the shared specification results in the 

formation of a continuous film:

If the liquid medium used in the coating process contains the polymer suspended as an aqueous dispersion, the polymer is initially deposited 

onto the core as discrete polymer spheres, which 

must then coalesce to form a continuous film. In 

such cases, a plasticizer may be added to the liquid medium to facilitate the coalescence process. 

On the other hand, if the liquid medium contains 

the polymer dissolved as a solution in an organic 
APTALIS PHARMATECH, INC. v. APOTEX INC. 11

solvent, a continuous film forms directly upon 

evaporation of the solvent. 

J.A. 1140–41, ¶ 9(c) (emphases added). A person of ordinary skill reading this Declaration would have understood 

that the extended release coatings of the invention were

continuous films. And an ordinarily skilled artisan would 

have understood the film to be an outer layer relative to 

the core because the coating is “deposited onto” the cores. 

We are not persuaded by Aptalis’ arguments in defense of the district court’s contrary construction. Aptalis 

first argues that the “applied onto the surface of the 

active-containing core” and “outer” requirements would 

exclude preferred embodiments. In Example 2, for instance, a seal coat is applied onto the active-containing 

core before the extended release coating, and an additional coating layer is added after the extended release coating. See ’199 patent col. 8 ll. 23–46. Because there is a 

seal coat between the extended release coating and the 

active-containing core, Aptalis argues that the extended 

release coating was applied onto the seal coat, not “onto 

the surface of the active-containing core.” Similarly, 

Aptalis interprets “outer” to mean “outermost” and points 

out that there is a coating layer applied onto the extended 

release coating in Example 2. 

Neither argument is persuasive. The specification refers to seal-coated active-containing cores as “core[s],” id.

at col. 7 ll. 4–14, so the presence of a seal coat does not 

mean that the extended release coating is not applied 

“onto the surface of the active-containing core.” And 

although Aptalis is correct that there is no basis for 

requiring the extended release coating to be the “outermost” coating, our construction imposes no such requirement. The extended release coating need only be an outer

coating relative to the active-containing core, which is 

consistent with Example 2’s teachings. 
12 APTALIS PHARMATECH, INC. v. APOTEX INC. 

Aptalis next asserts that the word “continuous” does 

not appear in the asserted patents and that a “continuous” extended release coating would not be functional 

because the coating must be permeable to gastrointestinal 

fluids. Aptalis conflates continuity with permeability, as 

demonstrated by Dr. McGinity’s Declaration: 

Extended release drug products may be made 

by coating water-insoluble polymers (e.g., the water-insoluble polymers claimed by Applicants) onto a core containing the active drug. In general, 

the applied polymer coatings do not dissolve when 

the drug product is ingested; instead, the coatings 

are semi-permeable such that water can enter and 

exit the core, thereby releasing the dissolved drug 

at a controlled rate. 

J.A. 1140, ¶ 9(a) (emphasis added). It follows that a 

continuous film covering the surface of the activecontaining core would not defeat the extended release 

functionality because the polymer coatings described by 

the invention are semi-permeable to water. 

Finally, Aptalis contends that the prosecution history 

is irrelevant to the claim construction question here 

because there is no clear and unmistakable disavowal of 

claim scope. Our precedent does not support this proposition. We have stated that “[a]ny explanation, elaboration, 

or qualification presented by the inventor during patent 

examination is relevant, for the role of claim construction 

is to ‘capture the scope of the actual invention’ that is 

disclosed, described, and patented.” Fenner Invs., Ltd. v. 

Cellco P’ship, 778 F.3d 1320, 1323 (Fed. Cir. 2015) (quoting Retractable Techs., Inc. v. Becton, Dickinson & Co., 

653 F.3d 1296, 1305 (Fed. Cir. 2011)). Although the 

prosecution history may lack the clarity imbued by the 

specification, it “can often inform the meaning of the 

claim language by demonstrating how the inventor understood the invention and whether the inventor limited 
APTALIS PHARMATECH, INC. v. APOTEX INC. 13

the invention in the course of prosecution, making the 

claim scope narrower than it would otherwise be.” Phillips, 415 F.3d at 1317. Accordingly, even in the absence of 

a clear and unmistakable disavowal, we conclude that the 

prosecution history can be evaluated to determine how a 

person of ordinary skill would understand a given claim 

term.

III.

We have considered the parties’ remaining claim construction arguments and find them unpersuasive. Because we conclude that the district court erred in 

construing the claims, we vacate and remand the district 

court’s infringement finding for further proceedings 

consistent with our claim construction.

VACATED AND REMANDED

COSTS

Costs to Appellants.