Jun Sang. Park et al.

Patent Trials and Appeals Board

Dec 2, 2019

12525058 - (D) (P.T.A.B. Dec. 2, 2019)

UNITED STATES PATENT AND TRADEMARK OFFICE
UNITED STATES DEPARTMENT OF COMMERCE
United States Patent and Trademark Office
Address: COMMISSIONER FOR PATENTS
P.O. Box 1450
Alexandria, Virginia 22313-1450
www.uspto.gov
APPLICATION NO. FILING DATE FIRST NAMED INVENTOR ATTORNEY DOCKET NO. CONFIRMATION NO.
12/525,058 07/29/2009 Jun Sang Park 16425-000002-US-NP 4725
28997 7590 12/02/2019
Harness Dickey (St. Louis)
7700 Bonhomme, Suite 400
ST. LOUIS, MO 63105
EXAMINER
CHANNAVAJJALA, LAKSHMI SARADA
ART UNIT PAPER NUMBER
1611
NOTIFICATION DATE DELIVERY MODE
12/02/2019 ELECTRONIC
Please find below and/or attached an Office communication concerning this application or proceeding.
The time period for reply, if any, is set in the attached communication.
Notice of the Office communication was sent electronically on above-indicated "Notification Date" to the
following e-mail address(es):
bkamer@hdp.com
stldocket@hdp.com
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
__________

BEFORE THE PATENT TRIAL AND APPEAL BOARD
__________

Ex parte JUN SANG PARK, U-HUN SONG, and JI-YEON SIM
__________

Appeal 2019-002636
Application 12/525,0581
Technology Center 1600
__________

Before FRANCISCO C. PRATS, DEBORAH KATZ, and
RACHEL H. TOWNSEND, Administrative Patent Judges.

TOWNSEND, Administrative Patent Judge.

DECISION ON APPEAL
This is an appeal under 35 U.S.C. § 134 involving claims to an oral
sustained-release triple-layer tablet, which have been rejected as failing to
comply with the written description requirement and/or as being obvious.
We have jurisdiction under 35 U.S.C. § 6(b).
We reverse.
STATEMENT OF THE CASE
Oral sustained-release formulations are used to control the release of
active ingredient at a designed rate and to obtain optimal therapeutic

1 We use the word “Appellant” to refer to “applicant” as defined in 37
C.F.R. § 1.42. Appellant identifies the real party in interest as GL
Pharmtech Corp. (Appeal Br. 3.)
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concentration in the blood of that active ingredient. (Spec. 1.) Dosage
forms that rely on “simple matrix containing water-soluble polymers” are
known, but have “some drawbacks such as an initial burst” of active
ingredient. (Id.) Attempts have been made “to introduce an additional
release-controlling layer into the matrix formulation, for the purpose of
avoiding an initial burst and initiating the release of active ingredient after a
predetermined time.” (Id.) Appellant’s invention is directed at a triple layer
tablet having
an inner immediate-release layer containing a pharmaceutically
active ingredient and two outer layers containing swellable
polymers. On exposure to aqueous media, the two outer layers
swell to form gelled layers surrounding the lateral side of the
inner layer rapidly, thereby control effectively the release of
drug from the inner immediate-release layer
(Id.)
Claims 13–17, 20–22, 24, and 27–33 are on appeal. Claim 32 is
representative and reads as follows:
32. An oral sustained-release triple-layer tablet comprising:
an inner immediate-release layer comprising a
pharmaceutically active ingredient, a pharmaceutical acceptable
diluent and a binder, and
two outer layers, each outer layer comprising a swellable
polymer which is polyethylene oxide having a viscosity of 400
cps or greater in 2% aqueous solution, or hydroxypropyl
methylcellulose having a viscosity of 4,000 cps or greater in 2%
aqueous solution, or a mixture of the polyethylene oxide and
the hydroxypropyl methylcellulose,
wherein the inner immediate-release layer is
characterized during dissolution testing in an aqueous medium
such that 80% or more of the pharmaceutically active ingredient
is released from the inner immediate-release layer without the
outer layers within one hour from exposure to the aqueous
medium,
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wherein the inner immediate-release layer has an exposed
lateral side which is not covered by the two outer layers,
wherein the two outer layers swell upon exposure to
aqueous medium to form gelled layers that surround the
exposed lateral side of the inner immediate-release layer, and
wherein the two outer layers comprise 40 to 95% by
weight of the swellable polymer, based on the total weight of
the tablet.
(Appeal Br. 24.)
The prior art relied upon by the Examiner is:
Name Reference Date
Dandiker 5,425,950 June 20, 1995
Conte et al. 5,626,874 May 6, 1997
Fassihi et al. 5,783,212 July 21, 1998
Fassihi et al. US 2006/0024368 A1 Feb. 2, 2006
Penhasi US 2006/0280795 A1 Dec. 14, 2006
DOW, Using Dow Excipients for Controlled Release of Drugs in
Hydrophilic Matrix Systems (2006), last accessed at www.dow.com June
25, 2011

The following grounds of rejection by the Examiner are before us on
review:
Claims 32 and 33 under 35 U.S.C. § 112, first paragraph, as failing to
comply with the written description requirement.
Claims 13–15, 20–22, 24, 32, and 33 under 35 U.S.C. § 103(a) as
unpatentable over Dandiker and Conte.
Claims 13–15, 20–22, 24, 28, 32, and 33 under 35 U.S.C. § 103(a) as
unpatentable over Dandiker, Conte, and Fassihi ’212 as evidenced by DOW.
Claims 13–16, 20–22, 24, and 27–33 under 35 U.S.C. § 103(a) as
unpatentable over Dandiker, Conte, Fassihi ’212 as evidenced by DOW, and
Fassihi ’368.
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Claims 13–17, 20–22, 24, and 27–33 under 35 U.S.C. § 103(a) as
unpatentable over Dandiker, Conte, Fassihi ’212, and Penhasi.
DISCUSSION
Written Description
The Examiner finds that claim 32 recites that the inner immediate-
release layer includes, inter alia, a “pharmaceutical acceptable diluent.”
(Final Action 5.) The Examiner notes that the Specification discloses
inclusion of “pharmaceutically acceptable excipients” but “lacks a
description of a ‘diluent’ per se.” (Id.) The Examiner recognizes that the
exemplary compositions comprise excipients but that “it is not clear that any
of these excipients are intended as ‘diluents’ and not a sweetener, binder,
and/or disintegrant.” (Id. at 6.)
We disagree with the Examiner’s conclusion that the Specification
does not provide support for the recitation of “diluent” in claim 32. “[T]he
test for sufficiency [of the written description] is whether the disclosure of
the application relied upon reasonably conveys to those skilled in the art that
the inventor had possession of the claimed subject matter as of the filing
date.” Ariad Pharm., Inc. v. Eli Lilly & Co., 598 F.3d 1336, 1351 (Fed. Cir.
2010) (en banc). To satisfy that test, it is not necessary that the application
describe the claim limitations exactly, but only so clearly that one having
ordinary skill in the relevant art would recognize from the disclosure that
Appellant invented the composition with the recited limitation. See In re
Herschler, 591 F.2d 693, 700–01 (CCPA 1979) (internal citations omitted)).
In particular, it is undisputed that a diluent is an excipient. (Ans. 16; Appeal
Br. 10; Reply Br. 2.) Moreover, it is undisputed that Appellant’s
Specification discloses excipients that are well-known diluents (Ans. 16–17
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(referring the Spec. ¶ 26); Appeal Br. 10), even if there are many more
diluents than those listed and even if some of the listed excipients can serve
in multiple roles in the pharmaceutical arts, such as being a filler. To
comply with the written description requirement, Appellant need not list
every known diluent in the pharmaceutical arts. Hybritech Inc. v.
Monoclonal Antibodies, Inc., 802 F.2d 1367, 1384 (Fed. Cir. 1986) (“[A]
patent need not teach, and preferably omits, what is well known in the art.”).
We agree with Appellant that “the disclosure [in the Specification] of
‘excipient’ in the inner immediate-release layer, particularly when paired
with the explicitly recited, well-known diluents [in the list of excipients that
may be included in the inner immediate-release layer], would ‘reasonably
convey’ to the skilled artisan that Appellant was in possession of an inner
immediate-release layer comprising a diluent.” (Appeal Br. 10.)
Thus, we reverse the rejection of claims 32 and 33 for lack of written
description support.
II
Non-Obviousness
The Examiner finds that Dandiker teaches a multi-layered tablet with
controlled release of an active agent that is part of the inner tablet layer but
that it does not teach a triple layer tablet as claimed where the inner layer has
an exposed lateral side. (Final Action 13, 15.) The Examiner finds that the
inner layer disintegrates rapidly, in less than 30 minutes, once exposed. (Id.
at 13.) The Examiner finds that the polymer of the outer layer “wets rapidly
to form a gel layer, fast enough to protect the interior of the dosage form
from either dissolving or disintegrating . . . .” (Id.)
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The Examiner finds that Conte is also directed to a three layered tablet
in lenticular form where “the central layer contains the active principle and
is exposed to the dissolution medium.” (Id. at 15.) The Examiner finds that
Conte’s external layers comprise swellable polymers that prevent, for a
programmable range of time, the release of the drug in the central layer.
(Id.) The Examiner notes that Conte teaches that this arrangement
overcomes the “inconsistent placement of the inner tablet” in a press-coating
of an inner tablet with an outer layer that “result[s] in inter-tablet
inconsistency in drug release and uncertainty in the effectiveness of the
tablet.” (Id.)
The Examiner concludes that it would have been obvious to a person
having “ordinary skill in the art seeking to improve the consistency of drug
release from the inner tablet of the tablets of Dandiker et al. to manufacture
the tablet using the method of Conte et al., using half of the outer layer
formulation of Ex. 12–15 . . . to form lower and upper external barrier
layers applied to a central core.” (Final Action 16.)
We disagree with the Examiner’s conclusion of obviousness.
Appellant’s claim 32, in addition to requiring an “inner immediate-release
layer [that] has an exposed lateral side which is not covered by the two outer
layers,” requires that the two outer layers swell upon exposure to aqueous
medium to form gelled layers that “surround the exposed lateral side of the
inner immediate-release layer.” We agree with Appellant, and there is no
dispute that, Dandiker describes a composition where the inner layer is
completely coated by an outer layer. In other words, Dandiker’s dosage
form looks like this,
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where the active ingredient is in the core that is completely surrounded by
two outer layers. The outer layer of Dandiker affects the release profile of
the active agent to achieve pulsed release. (See, e.g., Dandiker 3:17–28)
Conte’s dosage form, on the other hand, has three stacked layers, like
a sandwich,

(Conte Fig. 1). The active ingredient, as in Dandiker, is in the “central
layer.” However, in Conte, that central layer is exposed on the outer edges
and the initial release rate of the active ingredient is affected by how much
of the outer edge is presented to the dissolution environment. (Conte 3:30–
36.) The outer layers are not taught to swell around those edges to surround
them. Rather, Conte simply teaches those layers are selected so as to
prevent release of the active ingredient for a prearranged period of time
either by gelling or eroding to create a barrier, in conjunction with the
polymers included in the central layer which also act to modulate the release
of the active ingredient (id. at 4:31–34, 5:17–25). Conte explains that the
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barrier layers “leave exposed only a limited portion of the same core lateral
surface.” (Id. at 6:13–17.)
We agree with Appellant (Appeal Br. 15–16) that the two dosage
forms are very different in their arrangement of layers such that one of skill
in the art would not look to combine the two different structures together to
form some hybrid structure. We agree with Appellant that whether one were
modifying Dandiker in view of Conte or Conte in view of Dandiker, the
change in structure would be sufficiently different that the intended purpose
of the dosage form of either one of Dandiker or Conte would not be
achieved.
The Examiner states that “Dandiker also teaches that the outer
polymer layer does not have to be evenly distributed over the surface of the
core in order to provide a predictable release of the active agent.” (Ans. 19.)
However, that Dandiker does not have to be evenly coated and that the
thickness can be modified for a desired release rate does not equate to
providing a reason to provide a layer that leaves a portion of the core
uncovered. And the fact that both references are directed to oral drug
delivery systems and modulating the release of the active (id. at 22) does not
negate the very basic differences between these two dosage forms that if
modified in the way suggested by the Examiner would render their form to
operate in a vastly different manner than contemplated.
Dandiker teaches that “[t]he pharmaceutical compositions of the
invention are also able to provide a distinct pulse with no premature leakage
of the active ingredient from the core, even when highly water-soluble active
ingredients such as ranitidine are employed.” (Dandiker 3:3–6.) Modifying
Dandiker to not completely cover the core as in Conte would appear to allow
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for premature leakage. Indeed, the Examiner does not explain sufficiently,
nor do we ascertain from the portions of the references relied on by the
Examiner, that the combination would achieve a dosage form in which the
outer barrier layers swell to cover the exposed central/core surface if one
were to modify Dandiker with Conte. Conte does not appear to teach the
barrier layer is to swell to cover the central layer, and the Examiner has not
established Conte provides such a teaching.
It is not clear why the simple fact that Conte teaches leaving the
central layer open to control delivery would be motivation to do so in
Dandiker’s fully covered core dosage form that prevents premature leakage.
And it is not clear why one of ordinary skill in the art would modify Conte
to fully cover the central layer where Conte teaches that controlling the
amount of central layer surface that is exposed to aqueous medium in
combination with the barrier layer is the way to prevent, for a programmable
range of time, the release of the drug. (Conte 3:30–44, 5:17–19.)
For the foregoing reasons, we do not affirm the Examiner’s rejection
of claim 32 as being obvious over Dandiker and Conte.
This same deficiency applies to independent claims 13, 27, and 30 as
well. And none of the additional references cited by the Examiner to
address other limitations of the dependent claims addresses this gap in the
teachings of Dandiker and Conte. Accordingly, we reverse all of the
Examiner’s obviousness rejections.

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DECISION SUMMARY
In summary:
Claims
Rejected
35 U.S.C.
§
Reference(s)/Basis Affirmed Reversed
32, 33 112 First Paragraph,
Written
Description
32, 33
13–15, 20–
22, 24, 32,
33
Dandiker, Conte 13–15, 20–
22, 24, 32,
33
13–15, 20–
22, 24, 28,
32, 33
Dandiker, Conte,
Fassihi ’212, DOW
13–15, 20–
22, 24, 28,
32, 33
13–16, 20–
22, 24, 27–
33
Dandiker, Conte,
Fassihi ’212,
DOW, Fassihi ’368
13–16, 20–
22, 24, 27–
33
13–17, 20–
22, 24, 27–
33
Dandiker, Conte,
Fassihi ’212,
Penhasi
13–17, 20–
22, 24, 27–
33
Overall
Outcome
13–17, 20–
22, 24, 27–
33

REVERSED