DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Formal Matters
Receipt of Applicant’s response dated 08/05/2026 is acknowledged.
Claims 31-37 and 39-70 are pending.
Claims 1-30 and 38 are canceled.
Claims 31-32, 39-43, 45-46, and 48 are amended.
Claims 50-70 remain withdrawn from consideration as being drawn to a nonelected invention.
Claims 31-37 and 39-49 are under consideration in the instant Office action to the extent of the elected species, i.e., the modified cellulose is ethylcellulose, the water-insoluble, water-swellable cross-linked polycarboxylic polymer is polycarbophil, the pH regulator is sodium bicarbonate, and the active substance is diltiazem.
OBJECTIONS/REJECTIONS WITHDRAWN
Claim Objections
The objections to claims 31-32, 40, 42-43, 45, and 48 set forth in the Office action dated 04/16/2026 are hereby withdrawn in light of Applicant’s amendments to the claims.
Claim Rejections - 35 USC § 103
The rejection of claims 31-49 set forth in the Office action dated 04/16/2026 is hereby withdrawn in light of Applicant’s amendments to the claims and in favor of the new grounds of rejection set forth below as necessitated by Applicant’s amendments to the claims.
OBJECTIONS MAINTAINED
Claim Objections
Claims 41 and 46 remain objected to because each claim should be amended to remove comma appearing after the percent sign in line 1.
Appropriate correction is required.
Response to Applicant’s Arguments - Claim Objections
In Applicant’s remarks dated 08/05/2026, it is stated that “All of the objections to the claims identified by the Examiner have been addressed”, however a comma remains present after the percent sign in each of claims 41 and 46. For this reason, the objections to claims 41 and 46 are hereby maintained.
NEW GROUNDS OF REJECTION
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claims 31-49 are rejected under 35 U.S.C. 103 as being unpatentable over Caviglioli et al (US 2012/0122845 A1, published 05/17/2012) in view of Maddiboyina et al (Heliyon, 2020, 6, e0545, 1-12, published 11/13/2020).
Caviglioli et al teach a method for the preparation of a compact bioadhesive matrix, which can be a tablet, which comprises the following steps: preparing a uniform mixture of powders comprising at least one alkylcellulose or one hydroxyalkylcellulose and a non-water-soluble, water-swellable, cross-linked, polycarboxylic polymer; preparing compressed or compacted units starting from said powder mixture by direct compression or dry compaction; subjecting the compressed or compacted units thus obtained to heating at a temperature in the range of 80-250 °C, preferably in the range of 90-160 °C, for a time in the range of 1-60 minutes (See entire document, e.g., [0029]-[0032], [0038]). Caviglioli et al teach the at least one alkylcellulose or one hydroxyalkylcellulose may be selected from a group including ethylcellulose and the non-water-soluble, water-swellable, cross-linked, polycarboxylic polymer is preferably polycarbophil (e.g., [0002], [0036]-[0037]). Caviglioli et al teach that it is possible to use, in partial substitution of the at least one alkylcellulose or one hydroxyalkylcellulose, substances including excipients known for forming effervescent mixtures or systems (e.g., [0037]). Caviglioli et al teach that the powder mixtures can also comprise, and preferably comprises, at least one active substance, e.g., Diltiazem hydrochloride (e.g., Abstract, [0048], examples). Caviglioli et al teach that a preferred composition comprises an active substance, MicroceLac (i.e., an excipient), ethylcellulose, and polycarbophil, wherein polycarbophil generally constitutes 5-35% by weight of the total weight of the powder mixture before compression and heat treatment, wherein the combination of ethylcellulose and MicroceLac generally constitute 45-95% by weight of the total weight of the mixture before compression and heat treatment, wherein ethylcellulose and MicroceLac are generally present in the powder mixture in a weight ratio variable from 1:2 to 2:1, wherein ethylcellulose and polycarbophil are generally present in a weight ratio variable from 1:5 to 5:1, and wherein the active substance is contained in the powder mixture in a quantity variable from 0.001 ppm to 50% by weight of the total weight of the mixture before compression and heat treatment (e.g., [0048]-[0049], [0054]).
Caviglioli et al do not teach suitable excipients known for forming effervescent mixtures or systems, and therefore, do not specifically teach sodium bicarbonate as suitable.
This deficiency is made up for in the teaching of Maddiboyina et al.
Maddiboyina et al teach a gastro retentive drug delivery system, obtained by direct compression method, comprising a hydrophilic swelling agent/polymer, buoyancy enhancer, and gas generating agent (See entire document, e.g., Abstract). Maddiboyina et al teach ethylcellulose as buoyancy enhancer and sodium bicarbonate as gas generating agent, and exemplify a tablet comprising 20%–30 % w/w of hydrophilic swelling agent/polymer, 10% to 15% w/w of sodium bicarbonate as gas generating agent, and 5% to 10 w/w of ethylcellulose as buoyancy enhancer (e.g., Section 2.2.2 spanning Page 2 Col. 2 and Page 3 Col. 1).
It would have been prima facie obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, based on the teachings of Caviglioli et al and Maddiboyina et al, to provide a method for the preparation of a compact bioadhesive matrix, in the form of a tablet, comprising the following steps: preparing a uniform mixture of powders comprising ethylcellulose as the at least one alkylcellulose or one hydroxyalkylcellulose, 5-35% by weight of polycarbophil as the a non-water-soluble, water-swellable, cross-linked, polycarboxylic polymer, 10-15% by weight of sodium bicarbonate as an excipient known for forming effervescent mixtures or systems, and from 0.001 ppm to 50% by weight of diltiazem hydrochloride as the at least one active substance, wherein ethylcellulose and sodium bicarbonate are present in a combined amount of 45-95% by weight, ethylcellulose and sodium bicarbonate are present in a weight ratio variable from 1:2 to 2:1, and ethylcellulose and polycarbophil are generally present in a weight ratio variable from 1:5 to 5:1; preparing compressed or compacted units starting from said powder mixture by direct compression or dry compaction; subjecting the compressed or compacted units thus obtained to heating at a temperature in the range of 80-250 °C, preferably in the range of 90-160 °C, for a time in the range of 1-60 minutes.
One of ordinary skill in the art would have been motivated to include sodium bicarbonate as an excipient known for forming effervescent mixtures or systems in the powder mixture, and there would have been a reasonable expectation of success, because Caviglioli et al teach that excipients known for forming effervescent mixtures or systems may be included in the powder mixture and Maddiboyina et al teach sodium bicarbonate as a suitable gas generating agent in a gastro retentive drug delivery system, obtained by direct compression method, also comprising a hydrophilic swelling agent/polymer and ethylcellulose. One of ordinary skill in the art would have been motivated to include sodium bicarbonate in the powder mixture in an amount of 10-15% by weight, and there would have been a reasonable expectation of success, because Maddiboyina et al teach inclusion of 10-15% by weight of sodium bicarbonate as a gas generating agent in a gastro retentive drug delivery system, obtained by direct compression method, also comprising a hydrophilic swelling agent/polymer and ethylcellulose. One of ordinary skill in the art would have been motivated to include the combination of ethylcellulose and sodium bicarbonate in the powder mixture in an amount of 45-95% by weight, and there would have been a reasonable expectation of success, because Caviglioli et al teach that the combination of ethylcellulose and MicroceLac (i.e., an excipient) generally constitute 45-95% by weight of the total weight of the mixture before compression and heat treatment, Caviglioli et al teach that excipients may also include excipients known for forming effervescent mixtures or systems, and Maddiboyina et al teach sodium bicarbonate as a suitable gas generating agent in a gastro retentive drug delivery system, obtained by direct compression method, also comprising a hydrophilic swelling agent/polymer and ethylcellulose.
Regarding the ranges required by the instant claims, a prima facie case of obviousness typically exists when the ranges of a claimed composition overlap the ranges disclosed in the prior art (In re Peterson, 315 F.3d 1325, 1329 (Fed. Cir. 2003)). Specifically regarding the weight ratio range required by instant claim 44 and the weight percent ranges required by instant claims 45-46, where the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation (In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955)).
Because the method of Caviglioli et al in view of Maddiboyina et al comprises the steps of preparing a uniform mixture of powders comprising sodium bicarbonate as an excipient known for forming effervescent mixtures or systems, preparing compressed or compacted units starting from said powder mixture by direct compression or dry compaction, subjecting the compressed or compacted units thus obtained to heating at a temperature in the range of 80-250 °C, preferably in the range of 90-160 °C, for a time in the range of 1-60 minutes, and results in a compact bioadhesive matrix comprising sodium bicarbonate as an excipient known for forming effervescent mixtures or systems, the method of Caviglioli et al in view of Maddiboyina et al meets the limitation of “wherein the sodium bicarbonate is present in the homogeneous mixture prior to the direct compression or dry compaction step and remains incorporated in the compressed or compact units during the heating step” required by instant claim 1.
Because the matrix produced by the method of Caviglioli et al in view of Maddiboyina et al is the same as the matrix produced by the method of the instant claims, the matrix produced by the method of Caviglioli et al in view of Maddiboyina et al is necessarily gastroretentive. A chemical composition and its properties are inseparable. Therefore, if the prior art teaches the identical chemical structure, the properties applicant discloses and/or claims are necessarily present. "Products of identical chemical composition cannot have mutually exclusive properties" (In re Spada, 911 F.2d 705, 709, 15 USPQ2d 1655, 1658 (Fed. Cir. 1990). Mere recognition of latent properties in the prior art does not render nonobvious an otherwise known invention. In re Wiseman, 596 F.2d 1019, 201 USPQ 658 (CCPA 1979). "The fact that appellant has recognized another advantage which would flow naturally from following the suggestion of the prior art cannot be the basis for patentability when the differences would otherwise be obvious." Ex parte Obiaya, 227 USPQ 58, 60 (Bd. Pat. App. & Inter. 1985).
Thus, the method for the preparation of a compact bioadhesive matrix of Caviglioli et al in view of Maddiboyina et al renders obvious the method of instant claims 31-37 and 39-49.
Response to Applicant’s Arguments
Applicant’s arguments filed 08/05/2026 regarding the rejection under 35 USC 103 set forth 04/16/2026 have been fully considered by the Examiner, however are considered moot as the rejection under 35 USC 103 over Caviglioli et al in view of Nangia et al set forth in the Office action dated 04/16/2026 has been withdrawn and the combination of Caviglioli et al and Nangia et al is not being applied in a prior art rejection in the instant Office action. The Examiner notes that the art being applied as “Caviglioli et al” herein corresponds to US 2012/0122845 A1, published 05/17/2012, which is different from the “Caviglioli et al” art applied in the rejection under 35 USC 103 set forth in the Office action dated 04/16/2026.
Conclusion
No claims are allowed.
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to KAELEIGH ELIZABETH OLSEN whose telephone number is (703)756-1962. The examiner can normally be reached M-F 8-5 PM.
Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, David Blanchard can be reached at (571)272-0827. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000.
/K.E.O./Examiner, Art Unit 1619
/NICOLE P BABSON/Primary Examiner, Art Unit 1619
