Ex Parte Sawada et al

Board of Patent Appeals and Interferences

May 1, 2012

09834410 (B.P.A.I. May. 1, 2012)

UNITED STATES PATENT AND TRADEMARK OFFICE
__________

BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
__________

Ex parte TOYOHIRO SAWADA, KAZUHIRO SAKO, TATSUNOBU
YOSHIOKA, and SHUNSUKE WATANABE
__________

Appeal 2011-007934
Application 09/834,410
Technology Center 1600
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Before ERIC GRIMES, FRANCISCO C. PRATS, and JEFFREY N.
FREDMAN, Administrative Patent Judges.

GRIMES, Administrative Patent Judge.

DECISION ON APPEAL
This is an appeal under 35 U.S.C. § 134 involving claims relating to
timed-release drug compositions. The Examiner has rejected the claims as
obvious. We have jurisdiction under 35 U.S.C. § 6(b). We reverse.
STATEMENT OF THE CASE
Claims 1, 3, 5-7, 13-15, 18-21, and 24-36 are on appeal. Claim 1 is
representative and reads as follows:
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1. A timed-release compression-coated solid composition for oral
administration to a subject, said composition comprising:
a) a core tablet comprising a drug and a freely erodible filler, wherein
the freely erodible filler is 1 or 2 or more selected from the group consisting
of malic acid, citric acid, tartaric acid, polyethylene glycol having a
molecular weight of about 400 to 20,000, sucrose, and lactulose, wherein
said core tablet erodes approximately 40% to approximately 90% in the
digestive tract of said subject, wherein said core tablet does not contain a
hydrogel-forming polymer;
i) wherein said drug is metabolized by cytochrome P-450; or
ii) wherein said drug inhibits metabolism by cytochrome P-450; or
iii) wherein said drug is absorbed via a carrier on an epithelial cell of
the small intestine;
b) an outer layer, said outer layer is made from a hydrogel-forming
polymer substance and a hydrophilic base, wherein said hydrogel-forming
polymer substance is made from at least one type of polyethylene oxide with
a viscosity-average molecular weight of 2,000,000 or higher, and said
hydrophilic base is polyethylene glycol; and
c) wherein the outer layer does not contain the drug.

The Examiner has rejected claims 1, 3, 5-7, 13-15, 18-21, and 24-36
under 35 U.S.C. § 103(a) as being obvious in view of Giannini,1 Sako,2 and
Taniguchi.3 The Examiner finds that Giannini discloses granules of sucrose
coated with amoxicillin (Answer 4). The Examiner finds that the “coated
drug core is further coated with a combination of ethylcellulose and

1 Giannini et al., US 4,925,674, May 15, 1990. The Examiner actually refers
to U.S. Patent 4,925,675 as the “Evidence Relied Upon” (Answer 3), but
cites the correct reference in the statement of the rejection.
2 Sako et al., EP 0 661 045 A1, July 5, 1995.
3 Tanaka et al., EP 0 709,386 A1, May 1, 1996. The Examiner and
Appellants refer to this reference as “Taniguchi” (Answer 3-4, Appeal Br. 9)
so we do as well.
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polyethylene glycol.… Ethylcellulose is a hydrogel forming polymer and
polyethylene glycol is a hydrophilic polymer.” (Id.)
The Examiner finds that Sako discloses “a compression molded oral
formulation comprising a core comprising a drug …, along with solubilizers
… such as citric acid, tartaric acid, and polyethylene glycol,” which “is
coated with a hydrogel formulation comprising a hydrophilic base such as
polyethylene glycols … and hydrogel-forming polymers … such as
polyethylene oxides” (id. at 5). The Examiner finds that Sako’s formulation
can include drugs that are metabolized by CYP3A4 (cytochrome P-450) (id.)
and that, upon administration, “water is absorbed into the core of the
formulation during its stay in the upper intestine, essentially dissolving the
core and releasing the drug slowly as it travels to the colon” (id.).
The Examiner concludes that “it would have been obvious to combine
the prior art in order to provide a stable controlled release formulation with
improved lower digestive tract release. Following the suggestions of
[Giannini] to coat the core tablet with a mixture of polyethylene glycol and
oxide, it would have been obvious to use the fillers of [Sako] in order to
provide proper release of the core active agents.” (Id. at 7.) The Examiner
relies on Taniguchi only with regard to limitations of dependent claims (id.
at 5-6).
The Examiner also reasons that Giannini “provides the general
conditions of the instant claims but is deficient in the specific outer coating
hydrogel polymer and the specific drug.… [Sako] meets the drug and
coating deficiencies by disclosing an outer coating that is similar to that of
[Giannini’s], while disclosing the same polymer combination of the instant
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claims.” (Id. at 10.) The Examiner concludes that the “artisan of ordinary
skill would have been motivated to combine the coating of [Sako] to the
similar coating of [Giannini] … since the coating would have provide[d]
stable, steady and precise sustained release of the drug load along the GI
tract” (id. at 11).
Appellants argue that Sako discloses “a homogeneous tablet
formulation that comprises a drug, a hydrogel-forming polymer, and an
additive providing for the penetration of water into the core of the
preparation” (Appeal Br. 15). Appellants argue that “the Examiner cites
Sako and Taniguchi for allegedly providing filler, coating, and drug
elements to be substituted into the granule structure set forth in Giannini.…
The explicit motivation for this substitution of elements, however, is detailed
only in vague terms.” (Id. at 16.) Appellants argue that the Examiner has
not provided “a ‘clear articulation of the reason(s) why the claimed
invention would have been obvious.’” (Id.).
We agree with Appellants that the Examiner has not adequately
explained how the cited references would have made obvious the
composition of claim 1. “In rejecting claims under 35 U.S.C. § 103, the
examiner bears the initial burden of presenting a prima facie case of
obviousness.” In re Rijckaert, 9 F.3d 1531, 1532 (Fed. Cir. 1993).
Here, the Examiner has not provided evidence to show that, based on
the cited references, a person of ordinary skill in the art would have
considered it obvious to incorporate the polyethylene oxide of Sako’s
sustained release formulation into Giannini’s immediate release dosage
form. Giannini discloses granules that comprise “an inert seed which has a
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pharmaceutically active coating applied thereto.… A taste mask coating is
applied to the pharmaceutically active seed.” (Giannini, col. 4, ll. 27-30.)
The “taste mask coating preferably comprises a mixture of ethylcellulose
and polyethylene glycol” (PEG) (id. at col. 5, ll. 36-37). Giannini discloses
the amoxicillin granules with a taste masking coating of ethylcellulose and
PEG as an immediate release preparation (id. at col. 13, ll. 55-57).
Sako discloses a “sustained-release preparation comprising (1) at least
one drug, (2) an additive providing for a penetration of water into the core of
the preparation, and (3) a hydrogel-forming polymer, which preparation
undergoes … gelation during its stay in the upper digestive tract … and is
capable of releasing a drug in the colon” (Sako 2:40-43). Sako discloses that
the additive providing for water penetration can be PEG (id. at 3:52-58) and
that the hydrogel forming polymer is preferably polyethylene oxide (id. at
4:47). Sako discloses that the PEG, polyethylene oxide, and active agent are
mixed and then compression molded into tablets (id. at 12:21-26).
Thus, the ethylcellulose of Giannini and the polyethylene oxide of
Sako are performing different functions in their respective formulations: the
ethylcellulose in Giannini’s granules is intended to be part of a taste-mask
coating for an immediate release preparation, while the polyethylene oxide
of Sako is combined with the active agent and PEG so that a sustained
release gel encompassing the active agent is formed upon administration. In
view of these differences, the Examiner has not adequately explained why
one of skill in the art would have substituted the polyethylene oxide of Sako
for the ethylcellulose of Giannini.
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We disagree with the Examiner’s finding that, in Sako, a “core is
coated with a hydrogel formulation comprising a hydrophilic base such as
polyethylene glycols … and hydrogel-forming polymers … such as
polyethylene oxides” (Answer 5), because Sako describes making its
formulation as a homogeneous mixture of drug, hydrophilic base and
hydrogel-forming polymer (Sako 12:21-26). Although Sako states that a
sugar coating or film coating can then be applied to the above mixture (id. at
12:26-27), it does not suggest coating a drug tablet with a mixture of
hydrophilic base and hydrogel-forming polymer. Thus, we reverse the
rejection of independent claim 1 as being obvious in view of Giannini and
Sako.
Like claim 1, independent claims 21, 25, 27, and 30 also require
pharmaceutical compositions having an outer layer comprising polyethylene
oxide and PEG. Thus, the reasoning above also applies to these claims. We
therefore reverse the rejection of all of the claims on appeal.
SUMMARY
We reverse the rejection claims 1, 3, 5-7, 13-15, 18-21, and 24-36
under 35 U.S.C. § 103(a).

REVERSED

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