Ex Parte Prasad

Board of Patent Appeals and Interferences

May 18, 2010

11000878 (B.P.A.I. May. 18, 2010)

UNITED STATES PATENT AND TRADEMARK OFFICE
__________

BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
__________

Ex parte C. KRISHNA PRASAD
__________

Appeal 2009-011921
Application 11/000,878
Technology Center 1600
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Decided: May 18, 2010
__________

Before ERIC GRIMES, JEFFREY N. FREDMAN and STEPHEN WALSH,
Administrative Patent Judges.

WALSH, Administrative Patent Judge.

DECISION ON APPEAL
This is an appeal under 35 U.S.C. § 134(a) involving claims to a
method of making a metformin composition. The Patent Examiner rejected
the claims on the grounds of written description and obviousness. We have
jurisdiction under 35 U.S.C. § 6(b). We affirm.
Appeal 2009-011921
Application 11/000,878

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STATEMENT OF THE CASE
The invention relates to “methodologies and formulations used in the
creation of metformin hydrochloride tablets.” (Spec. 1:8-10.) According to
the Specification, “[a] problem associated with metformin HCl is that
metformin HCl, itself, cannot be readily compressed into a tablet.” (Id. at
1:18-20.) “To produce [Appellant’s] pharmaceutical composition, a binding
solution of povidone, starch and water is created.” (Id. at 5:1-3.)
Claims 10 and 13-17, which are all the pending claims, are on appeal.
Claim 10 is representative and reads as follows:
10. A method of creating a directly compressible pharmaceutical
composition that has metformin HCl as an active ingredient,
comprising the steps of:
providing metformin HCl;
creating a binding solution that contains starch, water, and a
binding catalyst that binds said starch to said metformin HCl;
mixing said binding solution with metformin HCl to form a first
composition;
drying said first composition to a moisture content of less than
2% by weight, wherein said first composition contains over 90%
metformin HCl by weight;
and
milling said first composition into granules.

The Examiner rejected the claims as follows:
• claims 10 and 13-17 under 35 U.S.C. § 112, first paragraph, as
failing to comply with the written description requirement;
• claims 10, 13-15 and 17 under 35 U.S.C. § 103(a) in view of
Cheng1 and Vandecruys;2 and

1 Xiu Xiu Cheng et al., U.S. Patent No. 6,099,859, issued Aug. 8, 2000.
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Application 11/000,878

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• claims 10 and 13-173 under 35 U.S.C. § 103(a) in view of Cheng,
Vandecruys and Rogosky.4
The claims have not been argued separately and therefore stand or fall
together. 37 C.F.R. § 41.37(c)(1)(vii).

WRITTEN DESCRIPTION
The Issue
The Examiner’s position is that the term “binding catalyst” “was not
described in the specification in such a way as to reasonably convey to one
skilled in the relevant art that the inventor[], at the time the application was
filed, had possession of the claimed invention.” (Ans. 4.) The Examiner
found that “binding catalyst” was used in the Specification “to solely
describe the role of povidone,” and not to describe types of material included
in the term. (Id.)
Appellant contends that there is “no law or rule that states that if an
example for a type of element is claimed [sic], an applicant can only claim
the example offered for that element and not the element itself.” (App. Br.
4-5.)

2 Roger Petrus Gerebern Vandecruys et al., U.S. Patent No. 6,667,060 B1,
issued Dec. 23, 2003.
3 The Examiner’s Answer omitted claim 16 from the claims rejected in an
apparent typo. (Compare Ans. 8 with Final Rej. 8 and App. Br. 8.)
4 Karen M. Rogosky, U.S. Patent No. 6,100,300, issued Aug. 8, 2000.
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Application 11/000,878

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Findings of Fact
1. The Specification states: “To help the starch bind the metformin HCl,
different molecular weights of povidone are added as binding
catalysts.” (Spec. 6:19-21.)
2. The Specification states: “The povidone binds to the metformin HCl
and acts as a binding catalyst for the pregelentinized [sic,
pregelatinized] starch.” (Id. at 8:10-12.)

Principles of Law
When an Applicant claims a class, the Applicant “must describe that
class in order to meet the description requirement of the statute.” In re
Lukach, 442 F.2d 967, 968 (CCPA 1971). “In written description cases,
‘[t]he primary consideration is factual and depends on the nature of the
invention and the amount of knowledge imparted to those skilled in the art
by the disclosure.’” Union Oil Co. of Cal. v. Atlantic Richfield Co.,
208 F.3d 989, 996 (Fed. Cir. 1991) (citation omitted, emphasis in original).
“The inquiry for adequate written description simply does not depend on a
particular claim format, but rather on whether the patent’s description would
show those of ordinary skill in the . . . art that the inventors possessed the
claimed invention at the time of filing.” Id. at 997-98.
The amount of description needed to meet the requirement can vary
with the scientific and technologic knowledge already in existence. Capon
v. Eshhar, 418 F.3d 1349, 1357 (Fed. Cir. 2005). “When no such
description can be found in the specification, the only thing the PTO can
reasonably be expected to do is point out its nonexistence.” Hyatt v. Dudas,
492 F.3d 1365, 1370 (Fed. Cir. 2007).
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Analysis
The Specification uses “binding catalyst” in only two places, and both
usages describe what povidone does. (FF 1 and 2.) We agree with (1) the
Examiner’s interpretation of the claims as using the term to represent a
genus of compounds, and (2) the Examiner’s finding that the Specification
did not describe the class of compounds included in the genus. Where the
Applicant “was clearly notified of what exactly the examiner felt was
missing by way of written description,” “[t]he burden was then properly
shifted to [the Applicant] to cite to the examiner where adequate written
description could be found, or to make amendment to address the
deficiency.” Hyatt v. Dudas, 492 F.3d 1365, 1371 (Fed. Cir. 2007).
Appellant has not cited where an adequate written description of the
“binding catalyst” class of compounds could be found, see Lukach, 442 F.2d
at 968, or made amendment to address the deficiency.
For example, if “binding catalyst” was known in the art as a generic
term for a group of compounds at the time the Application was filed,
Appellant could have offered relevant evidence that might have informed the
Examiner on the point. Capon, 418 F.3d at 1357; see also, Union Oil,
208 F.3d at 998-1000 (discussing evidence that apparently functional claim
terms were terms known to those skilled in the art for identifying
compositions). However, Appellant offered no explanation, evidence, or
amendment, to address the Examiner’s concerns, except to deny the burden
that Lukach and other cases place on the Applicant for patent. An Applicant
“cannot avoid addressing the PTO’s concerns by instead challenging the
PTO’s view that the burden was properly shifted.” Hyatt, 492 F.3d at 1371.

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OBVIOUSNESS
The Issue
The Examiner’s position is that Cheng taught the claimed method but
for the inclusion of starch in the binding solution. (Ans. 6.) The Examiner
found that Vandecruys taught advantages to using starch in hydrophilic
controlled release preparations, like Cheng’s, and concluded that it would
have been obvious to add starch to Cheng’s binding solution. (Id. at 6-7.)
The Examiner found that Rogosky taught using crospovidone in metformin
formulations, found that crospovidone added desireable features to tablets,
and concluded that it would have been obvious to include crospovidone in
Cheng’s method, along with starch as suggested by Vandecruys. (Id. at 8-9.)
Appellant contends that “[t]he combined references [Cheng and
Vandecruys] do not show the use of a binding catalyst to bind starch to
metformin in order to improve the compressibility of the metformin HCl.”
(App. Br. 7-8.) Appellant further contends that “[l]ike the Chen[g] and
Vandecruys patents, the Rogosky patent makes no disclosure of preparing a
binding solution of starch, water and a binding catalyst prior to mixing the
starch with the metformin HCl.” (Id. at 9.)

Further Findings of Fact
3. Cheng’s Example 1 described preparation of a controlled release
metformin HCl tablet comprising 90.54% metformin HCl, 4.38%
povidone, 4.58% sodium tribasic phosphate, and 0.5% magnesium
stearate. (Cheng, col. 6, ll. 1-15.)
4. Cheng’s Example 1 described the steps:
providing metformin HCl (id. at col. 6, ll. 19-22);
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creating a binding solution that contained povidone K-30 and sodium
tribasic phosphate in water (id. at col. 6, ll. 22-23);
mixing the binding solution with metformin HCl (id. at col. 6, ll. 23-
29);
drying the granules until the loss on drying was less than 2% (id. at
col. 6, ll. 30-32); and
passing the dried granules through a Comil equipped with an 18 mesh
screen (id. at col. 6, ll. 32-33).
5. Vandecruys taught that pregelatinized starch should be used to
prevent “dose-dumping” from hydrophilic controlled release drug
formulations. (Vandecruys, col. 4, ll. 7-31.)
6. According to Vandecruys, dose-dumping “is well known by a person
skilled in the art and defines a sudden release of a major part or all of
the active ingredient(s) incorporated in a formulation intended to be
used as a controlled release formulation.” (Id. at col. 4, ll. 57-60.)
7. Vandecruys taught using pregelatinized starch in formulations
comprising anti-diabetic drugs such as metformin HCl (id. at col. 5, l.
65), and povidones (id. at col. 9, ll. 26-30).
8. Vandecruys taught that the weight percentage of pregelatinized starch
should range “preferably from about 0.01% to about 5%.” (Id. at col.
8, ll. 55-60.)
9. The Examiner found that preventing dose-dumping would have been
very desirable for “sustained bioavailability especially in a diabetic.”
(Ans. 6.)
10. The Examiner found that pregelatinized starch was commonly used,
and “especially favorable for hydrophilic drugs like metformin.” (Id.)
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11. The Examiner found that “[m]etformin is a hydrophilic drug and any
means to stabilize and produce controlled release for appropriate and
sustained bioavailability of the drug, especially for diabetics where
good sugar stabilization is not available, and to prevent dose-dumping
(sudden release of the drug) is very desirable.” (Id. at 7.)
12. The Examiner found that starch is “substantially less expensive than”
povidone, and that it would have been desirable to substitute starch for
some portion of the povidone. (Id.)
13. Rogosky taught formulating metformin HCl in tablets with
crospovidone or starch, and magnesium stearate. (Rogosky, col. 4, ll.
28-42.)

Principles of Law
A rejection for obviousness must include “articulated reasoning with
some rational underpinning to support the legal conclusion.” KSR Int’l Co.
v. Teleflex Inc., 550 U.S. 398, 418 (2007), quoting In re Kahn, 441 F.3d 977,
988 (Fed. Cir. 2006). The proper question to ask is whether a person of
ordinary skill in the art, facing the wide range of needs created by
developments in the field of endeavor, would have seen a benefit to
combining the prior art teachings. KSR, 550 U.S. at 424; see also In re
Fulton, 391 F.3d 1195, 1200 (Fed. Cir. 2004) (the desirability of the
combination may arise from nature of the problem, teachings of references,
or the ordinary knowledge of those skilled in the art). “The combination of
familiar elements according to known methods is likely to be obvious when
it does no more than yield predictable results.” KSR, 550 U.S. at 416. “[I]f
a technique has been used to improve one device, and a person of ordinary
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Application 11/000,878

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skill in the art would recognize that it would improve similar devices in the
same way, using the technique is obvious unless its actual application is
beyond his or her skill.” KSR, 550 U.S. at 417. “One of the ways in which a
patent’s subject matter can be proved obvious is by noting that there existed
at the time of invention a known problem for which there was an obvious
solution encompassed by the patent’s claims.” Id. at 419-420.

Analysis
Appellant contends that “[t]he combined references [Cheng and
Vandecruys] do not show the use of a binding catalyst to bind starch to
metformin in order to improve the compressibility of the metformin HCl.”
(App. Br. 7-8.) The Examiner has not relied on evidence that starch was
known for its ability to improve compressibility. The Examiner instead
relied on Vandecruys’ teachings regarding starch’s ability to alleviate the
dose-dumping problem for hydrophilic controlled release formulations like
Cheng’s metformin formulation. Appellant has not challenged the
correctness of the Examiner’s finding that avoiding dose-dumping was a
known problem, particularly for diabetic patients, and that it would have
been alleviated by applying Vandecruys’ teaching to add starch at the
binding solution step in Cheng’s method. Appellant’s claims encompass
that obvious solution. See KSR, 550 U.S. at 419-420. To show obviousness,
it is not necessary that the prior art address the identical problem that an
Applicant addresses. See KSR, 550 U.S. at 419 (“In determining whether the
subject matter of a patent claim is obvious, neither the particular motivation
nor the avowed purpose of the patentee controls. What matters is the
objective reach of the claim.”).
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As to Appellant’s contention that the combined references do not
disclose “preparing a binding solution of starch, water and a binding catalyst
prior to mixing the starch with the metformin HCl” (App. Br. 9), the
combined references suggest that step. Cheng explicitly disclosed preparing
a binding solution of povidone (a binding catalyst) in water prior to mixing
the povidone solution with the metformin. (FF 4.) The Examiner explained
how Vandecruys suggested adding starch, and why it would have been
obvious to include the starch in the binding solution. The evidence supports
the Examiner’s reliance on specific teachings in the references, and
Appellant does not challenge the Examiner’s additional findings of general
knowledge in the art concerning cost considerations and the desirability of
avoiding dose-dumping particularly for diabetic patients.

CONCLUSION
The evidence supports the Examiner’s findings concerning the scope
and content of the prior art, and Appellant does not challenge the Examiner’s
findings of general knowledge in the art concerning cost of starch and the
particular need to reduce dose-dumping for diabetic patients. We conclude
that the rejections properly set out a prima facie case of obviousness.

SUMMARY
We affirm the rejection of claims 10 and 13-17 under 35 U.S.C.
§ 112, first paragraph, as failing to comply with the written description
requirement.
We affirm the rejection of claims 10, 13-15 and 17 under 35 U.S.C.
§ 103(a) in view of Cheng and Vandecruys.
Appeal 2009-011921
Application 11/000,878

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We affirm the rejection of claims 10 and 13-17 under 35 U.S.C.
§ 103(a) in view of Cheng, Vandecruys and Rogosky.
No time period for taking any subsequent action in connection with
this appeal may be extended under 37 C.F.R. § 1.136(a).

AFFIRMED

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