Ex parte Allen et al.

Board of Patent Appeals and Interferences

Apr 15, 1998

07994040 (B.P.A.I. Apr. 15, 1998)

Application for patent filed December 21, 1992. 1
According to appellants, this application is a continuation of
Application 07/449,961 filed December 11, 1989, now abandoned.
1
THIS OPINION WAS NOT WRITTEN FOR PUBLICATION
The opinion in support of the decision being entered today (1)
was not written for publication in a law journal and (2) is
not binding precedent of the Board.
Paper No. 29
UNITED STATES PATENT AND TRADEMARK OFFICE
__________
BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
__________
Ex parte DOUGLAS J. M. ALLEN and KEVIN M. NEPVEUX
__________
Appeal No. 95-4433
Application No. 07/994,0401
__________
ON BRIEF
__________
Before GARRIS, OWENS and WALTZ, Administrative Patent Judges.
GARRIS, Administrative Patent Judge.
DECISION ON APPEAL
This is a decision on an appeal from the final rejection
of claims 1 through 3 which are all of the claims in the
application.
Appeal No. 95-4433
Application No. 07/994,040
2
The subject matter on appeal relates to crystalline
azithromycin dihydrate and to a method for the preparation
thereof. Further details of this subject matter are readily
apparent from a review of the appealed claims which read as
follows:
1. Crystalline azithromycin dihydrate.
2. A method of preparing crystalline azithromycin
dihydrate which comprises crystallization of amorphous
azithromycin or azithromycin monohydrate from a mixture of
tetrahydrofuran and a (C -C ) aliphatic hydrocarbon in the5 7
presence of at least 2 molar equivalents of water.
3. A method of claim 2 wherein the hydrocarbon is
hexane.
The references relied upon by the examiner as evidence of
obviousness are:
Desposato et al. (Desposato) 4,219,641 Aug.
26, 1980
Bright 4,474,768 Oct. 2,
1984
Claims 1 through 3 stand rejected under 35 U.S.C. § 103
as being unpatentable over Bright in view of Desposato.
This rejection cannot be sustained.
Appeal No. 95-4433
Application No. 07/994,040
On the record before us, it is undisputed that2
azithromycin monohydrate constitutes the product of Example 3.
3
On this appeal, the examiner and the appellants have
advanced respectively reference evidence of obviousness and
declaration evidence of nonobviousness. Accordingly, we will
assess the patentability of the here claimed invention under
35 U.S.C. § 103 based upon the totality of the record, by a
preponderance of evidence with due consideration to
persuasiveness of argument. In re Oetiker, 977 F.2d 1443,
1445, 24 USPQ2d 1443, 1444 (Fed. Cir. 1992).
Example 3 of the Bright reference discloses making a
crystalline product said to constitute azithromycin
monohydrate using ethanol and water. Consistent with the2
appellants’ arguments, it is questionable whether one with
ordinary skill in the art would have found in the Desposato
reference any reason, suggestion or incentive to modify
Bright’s aforementioned disclosure in such a manner as to
obtain a crystalline azithromycin dihydrate as required by
appealed claim 1 or a method for the preparation thereof from
a mixture of tetrahydrofuran and a (C -C ) aliphatic5 7
hydrocarbon in the presence of at least two molar equivalents
Appeal No. 95-4433
Application No. 07/994,040
4
of water as required by appealed claim 2. This is because
Desposato, although disclosing the existence of erythromycin
dihydrate (see line 6 in column 3), contains no disclosure
regarding the crystalline form of this compound much less
crystalline azithromycin dihydrate. Similarly, although
patentee discloses crystallizing erythromycin ethyl succinate
from an aqueous mixture containing tetrahydrofuran as solvent
or ethyl acetate as solvent combined with hexane (e.g., see
lines 37 through 56 in column 1), Desposato contains no
disclosure of using a mixture of tetrahydrofuran and a C -C5 7
aliphatic hydrocarbon in the presence of at least two molar
equivalents of water in order to prepare crystalline
azithromycin dihydrate.
As rebuttal evidence, the appellants have advanced a
number of declarations. These declarations include the
Forcier Declaration signed March 19, 1992 and the Hangac
Declaration signed February 16, 1994 which compare
respectively the hygroscopicity and stability characteristics
of crystalline azithromycin dihydrate and azithromycin
monohydrate. Notwithstanding the examiner’s criticisms
thereof, these declarations quite plainly show that the
Appeal No. 95-4433
Application No. 07/994,040
5
aforementioned characteristics of crystalline azithromycin
dihydrate are significantly and unexpectedly superior to those
of crystalline azithromycin monohydrate.
Under the circumstances recounted above, it is our
determination that the evidence of record, on balance, weighs
most heavily in favor of a nonobviousness conclusion. It
follows that we cannot sustain the examiner’s § 103 rejection
of claims 1 through 3 as being unpatentable over Bright in
view of Desposato.
Appeal No. 95-4433
Application No. 07/994,040
6
The decision of the examiner is reversed.
REVERSED
BRADLEY R. GARRIS )
Administrative Patent Judge)
)
)
)
TERRY J. OWENS ) BOARD OF
PATENT
Administrative Patent Judge) APPEALS AND
) INTERFERENCES
)
)
THOMAS A. WALTZ )
Administrative Patent Judge)
Appeal No. 95-4433
Application No. 07/994,040
7
Gregg C. Benson
Pfizer Inc.
Eastern Point Road
Groton, CT 06340