Details for Patent: 8,361,972

Which drugs does patent 8,361,972 protect, and when does it expire?

Patent 8,361,972 protects BYDUREON, BYDUREON PEN, BYDUREON BCISE, FARXIGA, and QTERN, and is included in four NDAs.

Protection for BYDUREON has been extended six months for pediatric studies, as indicated by the *PED designation in the table below.

This patent has sixty-three patent family members in twenty-eight countries.

Summary for Patent: 8,361,972

Title:	Pharmaceutical formulations containing an SGLT2 inhibitor
Abstract:	Pharmaceutical formulations are provided which are in the form of capsules or tablets for oral use and which include a medicament dapagliflozin or its propylene glycol hydrate and a pharmaceutical acceptable carrier therefor, which formulation is designed for immediate release.
Inventor(s):	Dilbir S. Bindra, Mandar V. Dali, Prakash V. Parab, Jatin M. Patel, Li Tao, Ravindra W. Tejwani, Nipa Vatsaraj, Yongmei Wu
Assignee:	AstraZeneca AB
Application Number:	US13/529,463
Patent Litigation and PTAB cases:	See patent lawsuits and PTAB cases for patent 8,361,972
Patent Claim Types: see list of patent claims	Use; Composition; Formulation; Dosage form;

United States Patent 8,361,972: Dapagliflozin Formulation Claims, Scope, Expiration and Generic Risk

United States Patent No. 8,361,972 protects methods of treating diabetes and related metabolic disorders using immediate-release formulations containing dapagliflozin propylene glycol hydrate. The strongest protection is concentrated in formulation-specific claims covering excipient ranges, exact tablet compositions, and two capsule stock-granulation embodiments. The patent does not broadly claim dapagliflozin as a chemical entity or every dapagliflozin product.

The patent’s commercial relevance depends on whether an accused generic uses the claimed dapagliflozin propylene glycol hydrate form and falls within the specified excipient, dosage-form, and immediate-release limitations. A product containing dapagliflozin but using a different solid form, formulation architecture, or noninfringing excipient profile may avoid literal infringement.

What does United States Patent 8,361,972 protect?

Patent 8,361,972 protects a method of treating or delaying the onset or progression of diabetes and associated metabolic diseases by administering an immediate-release pharmaceutical formulation containing dapagliflozin propylene glycol hydrate. The formulation must be a tablet, capsule, or stock granulation and must contain specified classes of excipients. (U.S. Patent No. 8,361,972, 2013).

The protected subject matter has four principal layers:

Protection layer	Claims	Core limitation
Broad treatment and formulation combination	1	Immediate-release dapagliflozin propylene glycol hydrate formulation with defined excipient categories and ranges
Dosage form	3-4	Capsule or tablet
Formulation composition	5, 11	Defined ranges for active ingredient, lactose, microcrystalline cellulose, disintegrants, glidants and magnesium stearate
Specific commercial-style embodiments	6-10, 12-15	Exact capsule granulations and 1 mg, 2.5 mg, 5 mg, 10 mg and 50 mg tablet embodiments
Diabetes treatment and combination therapy	16-22	Type 2 diabetes and coadministration with other antidiabetic, lipid-lowering, antihypertensive or anti-obesity agents

The patent is a formulation and method-of-use patent. It is not principally a compound patent.

How broad is independent claim 1?

Claim 1 is broad in therapeutic scope but narrower in pharmaceutical implementation.

Therapeutic scope

The claim covers treatment or delayed progression of:

• Type 1 and Type 2 diabetes
• Impaired glucose tolerance
• Insulin resistance
• Nephropathy, retinopathy, neuropathy and cataracts
• Hyperglycemia and hyperinsulinemia
• Hypercholesterolemia, dyslipidemia, hyperlipidemia and hypertriglyceridemia
• Obesity
• Wound healing and tissue ischemia
• Atherosclerosis and hypertension
• Metabolic Syndrome, also called Syndrome X

The broad disease list expands the potential method-of-use coverage. It also creates claim-construction and validity questions because the formulation limitations, rather than the disease list, are likely to determine practical infringement.

Pharmaceutical limitations

Claim 1 requires all of the following:

1. Dapagliflozin propylene glycol hydrate.
2. An immediate-release formulation.
3. A tablet, capsule or stock granulation.
4. A daily dose of approximately 0.1 mg to 750 mg.
5. Administration one to four times daily.
6. Active ingredient content of 0.1% to 70% of tablet or capsule fill.
7. One or more specified bulking agents or binders.
8. Optional disintegrants within stated maximum ranges.
9. Talc or silicon dioxide as glidant or anti-adherent.
10. Magnesium stearate at 0.1% to 5% of tablet or capsule fill.

A generic manufacturer would therefore face a literal infringement risk only if its product and proposed use satisfy the full combination. A tablet that contains dapagliflozin propylene glycol hydrate but omits magnesium stearate, uses a different solid form, or falls outside the relevant formulation ranges may avoid literal infringement of claim 1.

What do claims 5 through 15 add?

Claims 5 through 15 provide the patent’s most commercially focused formulation protection.

Claim 5: broad formulation platform

Claim 5 requires:

• Dapagliflozin propylene glycol hydrate at approximately 0.1% to 30%.
• Lactose and/or microcrystalline cellulose as bulking agents.
• Pregelatinized starch as binder.
• Croscarmellose sodium, crospovidone or sodium starch glycolate as disintegrant.
• Talc and/or silicon dioxide as glidant or anti-adherent.
• Magnesium stearate at approximately 0.2% to 2%.
• An optional protective coating.

This claim is broader than the exact-dose claims but narrower than claim 1 because it requires a particular excipient architecture.

Claims 6 and 7: capsule stock granulations

These claims cover two specific capsule compositions:

Component	Claim 6	Claim 7
Dapagliflozin propylene glycol hydrate	10.00%	22.80%
Microcrystalline cellulose	68.75%	55.95%
Pregelatinized starch	15.00%	15.00%
Sodium starch glycolate	3.00%	3.00%
Silicon dioxide	2.00%	2.00%
Magnesium stearate	1.25%	1.25%

These claims are narrow but potentially valuable if the reference formulation was used in development, clinical testing or an authorized product. Their exact-percentage limitations make them easier to design around than claims based on broader ranges.

Claims 8 through 10: exact tablet formulas

Claims 8, 9 and 10 cover 2.5 mg, 10 mg and 50 mg dapagliflozin dose tablets. The 2.5 mg and 10 mg formulations use the same principal excipients, with the active ingredient and microcrystalline cellulose adjusted for dose strength.

Ingredient	2.5 mg tablet	10 mg tablet	50 mg tablet
Dapagliflozin propylene glycol hydrate	3.08 mg	12.30 mg	61.66 mg
Microcrystalline cellulose	67.11 mg	57.89 mg	114.09 mg
Anhydrous lactose	25.00 mg	25.00 mg	62.60 mg
Crospovidone	8.75 mg	8.75 mg	21.91 mg
Croscarmellose sodium	3.75 mg	3.75 mg	9.39 mg
Talc	12.50 mg	12.50 mg	31.30 mg
Silicon dioxide	2.88 mg	2.88 mg	7.20 mg
Magnesium stearate	1.94 mg	1.94 mg	4.85 mg

Claims 8 through 10 are vulnerable to formulation substitution because they require a precise composition. They are strongest where a competitor’s formulation substantially reproduces the claimed quantities.

Claims 12 through 15: dose-specific range claims

Claims 12 through 15 cover 1 mg, 2.5 mg, 5 mg and 10 mg tablets using specified active-ingredient amounts and excipient ranges. They also allow an antioxidant or chelating agent in an amount of zero, making that element optional.

The claims cover:

• 1.23 mg of hydrate for a 1 mg dapagliflozin dose.
• 3.075 mg for a 2.5 mg dose.
• 6.15 mg for a 5 mg dose.
• 12.3 mg for a 10 mg dose.

These claims are more flexible than claims 8 through 10 because several excipients are defined by ranges. They may present greater design-around difficulty for a generic using the same conventional direct-compression or granulation platform.

What is the scope of claim 2?

The text supplied for claim 2 is incomplete: “wherein the dapagliflozin propylene glycol hydrate is...” The missing limitation prevents a complete claim construction.

Claims 17 and 22 depend on claim 2, so their scope also cannot be determined from the supplied text. The operative issued patent document, including the complete claim language and certificate history, controls over an incomplete transcription.

What patent protects the dapagliflozin active ingredient?

The principal early dapagliflozin compound protection is associated with U.S. Patent No. 6,515,117, which covers C-aryl glucoside SGLT2 inhibitors, including dapagliflozin-related compounds. That patent is distinct from U.S. Patent No. 8,361,972, which focuses on pharmaceutical formulations and treatment methods. (U.S. Patent No. 6,515,117, 2003).

The relevant patent estate should be separated into four categories:

Estate segment	Representative protection	Commercial purpose
Chemical compound	U.S. Patent No. 6,515,117	Dapagliflozin and related SGLT2 inhibitors
Solid form	Dapagliflozin propylene glycol hydrate patents and applications	Controls the active pharmaceutical ingredient form
Formulation	U.S. Patent No. 8,361,972	Immediate-release tablets, capsules and granulations
Therapeutic use	Diabetes, heart failure, renal and cardiometabolic indications	Controls selected clinical uses

A freedom-to-operate review must evaluate the entire family and not only patent 8,361,972. A generic could avoid this patent while still encountering compound, solid-form, method-of-use or manufacturing patents.

When does United States Patent 8,361,972 expire?

The patent issued on February 5, 2013. Its effective expiration depends on the earliest effective nonprovisional filing date, patent-term adjustment, terminal disclaimers and any applicable extension.

Based on the patent’s priority and filing history, the ordinary statutory term is generally expected to fall in the late 2020s, subject to the official USPTO term calculation. The relevant date for regulatory and litigation analysis is the expiration date recorded in the FDA Orange Book and the USPTO Patent Center record, not the issue date.

Milestone	Date
Patent issued	February 5, 2013
Patent number	8,361,972
Patent type	Formulation and method-of-use
Regulatory relevance	Potential Orange Book listing for dapagliflozin products
Expiration analysis	Filing date plus 20 years, adjusted for PTA and any disclaimer

Patent expiration does not automatically remove all dapagliflozin market barriers. Separate listed patents, pediatric exclusivity, unlisted patents, regulatory exclusivity and litigation settlements may affect launch timing.

What is the Orange Book status of patent 8,361,972?

The Orange Book is the controlling FDA source for patents listed against approved small-molecule drug products. A patent’s presence or absence in the Orange Book affects the statutory certification pathway available to an ANDA applicant. (FDA, 2024a).

For an ANDA applicant, the key possibilities are:

• Paragraph I: no patent information is listed.
• Paragraph II: the listed patent has expired.
• Paragraph III: approval is requested after patent expiration.
• Paragraph IV: the applicant asserts that the patent is invalid, unenforceable or not infringed.

The commercial importance of patent 8,361,972 depends on whether it remains listed against the relevant dapagliflozin reference product and whether the listed claims correspond to the approved product’s formulation or approved uses. An Orange Book listing does not establish infringement or validity. It triggers regulatory procedures and, if challenged, can support a 30-month stay following timely patent litigation. (FDA, 2024b).

Which companies are challenging dapagliflozin exclusivity?

Dapagliflozin has attracted ANDA activity because Farxiga is a high-revenue SGLT2 inhibitor marketed by AstraZeneca. Publicly reported generic activity has involved multiple manufacturers and has generated Paragraph IV litigation concerning different Farxiga patents and patent families.

The relevant potential challengers include major U.S. and Indian generic manufacturers such as:

• Aurobindo
• Zydus
• Lupin
• Sun Pharmaceutical
• Torrent Pharmaceuticals
• Alembic
• MSN Laboratories
• Other ANDA applicants identified in FDA and federal court records

The precise defendant list must be matched to each asserted patent. A company named in litigation over a compound, solid-form or method-of-use patent is not necessarily challenging patent 8,361,972. Litigation dockets, Paragraph IV notices and settlement terms should be reviewed patent by patent.

What generic entry risks exist for Farxiga?

The main generic-entry scenarios are as follows:

Scenario	Effect on patent 8,361,972
Generic uses a different solid form	Potentially avoids claims requiring dapagliflozin propylene glycol hydrate
Generic uses the same hydrate but changes excipients	May avoid narrow composition claims, but claim 1 risk remains
Generic copies dose and excipient architecture	Higher literal infringement risk under claims 5 and 11-15
Generic uses a carved-out indication	May reduce method-of-use exposure, but formulation claims remain relevant
Generic launches after patent expiration	Patent 8,361,972 no longer blocks launch
Authorized generic or settlement launch	Entry date depends on settlement and regulatory terms

The most important technical design-around is substitution of the active pharmaceutical ingredient form. If the approved or proposed generic contains an anhydrous form, a different hydrate, a co-crystal or another solid-state form, the “dapagliflozin propylene glycol hydrate” limitation may not be satisfied. That strategy must be tested against the actual pharmaceutical form, not merely the label’s use of the word dapagliflozin.

How strong is the patent estate for patent 8,361,972?

The estate is strongest against a competitor that reproduces the claimed formulation platform. It is weaker as a standalone barrier against all dapagliflozin products.

Strengths

• Claims cover both treatment and formulation.
• Claims reach tablets, capsules and stock granulations.
• Claims cover commercially relevant dapagliflozin dose strengths.
• Claims 11 through 15 use ranges rather than only exact compositions.
• The formulation includes common excipients likely to appear in immediate-release products.

Weaknesses and challenge points

• The patent requires dapagliflozin propylene glycol hydrate, creating a solid-form dependency.
• Exact-percentage claims are comparatively easy to modify.
• The therapeutic list is broad relative to the formulation disclosure.
• The 0.1 mg to 750 mg dose range may create written-description and enablement arguments at its outer limits.
• Claims that use optional excipient ranges may raise interpretation issues regarding the required combination of components.
• A method claim requires proof of administration for the claimed treatment, not merely manufacture or sale of a tablet.

The patent’s practical strength is therefore medium to high against a close formulation copy and moderate or low against a carefully engineered design-around.

What manufacturing and intellectual-property barriers remain after expiration?

Manufacturing barriers may persist even after patent expiry. Dapagliflozin propylene glycol hydrate requires control of:

• Solid-state form and hydration state.
• Crystallization conditions.
• Water activity and residual solvent.
• Particle-size distribution.
• Blend uniformity at low dose strengths.
• Content uniformity.
• Granulation and compression behavior.
• Dissolution and stability.
• Analytical methods capable of distinguishing solid forms.

These manufacturing parameters can create process know-how that is separate from patent 8,361,972. Trade secrets, regulatory requirements and supply-chain qualification may delay launch even when patent barriers fall away.

How does patent 8,361,972 compare with biologic exclusivity?

Dapagliflozin is a small molecule, not a biologic. The relevant competitive pathway is an ANDA with paragraph certifications, not a biosimilar application under the Biologics Price Competition and Innovation Act.

There is no biosimilar risk for dapagliflozin. The competitive risks are generic substitution, authorized generic entry, formulation design-around and indication-specific labeling. FDA approval depends on pharmaceutical equivalence, bioequivalence and compliance with applicable patent certifications. (FDA, 2024b).

Does the patent cover Farxiga’s approved clinical uses?

Farxiga is approved for several indications, including Type 2 diabetes, heart failure and chronic kidney disease. The supplied claims expressly cover Type 2 diabetes and numerous metabolic conditions, but they do not automatically cover every later-approved indication.

Claims 16 through 22 narrow the invention to Type 2 diabetes and combination therapy. They may be relevant to a product label that includes Type 2 diabetes treatment. They do not create a universal block against all dapagliflozin uses.

Key Takeaways

• U.S. Patent 8,361,972 is a formulation and method-of-use patent, not the foundational dapagliflozin compound patent.
• Claim 1 requires dapagliflozin propylene glycol hydrate in an immediate-release tablet, capsule or stock granulation with specified excipient categories.
• Claims 6 through 10 protect exact capsule and tablet compositions.
• Claims 11 through 15 provide broader dose-specific formulation coverage.
• A generic using a different dapagliflozin solid form or substantially different excipient system may have a credible design-around.
• Paragraph IV risk depends on the patent’s current Orange Book listing and the formulation used by each ANDA applicant.
• Dapagliflozin has no biosimilar pathway because it is a small molecule.
• Patent 8,361,972 should be analyzed with compound, solid-form, method-of-use and manufacturing patents in the broader Farxiga estate.
• The supplied text for claim 2 is incomplete, preventing a complete analysis of claims 2, 17 and 22.

FAQs

Does patent 8,361,972 cover dapagliflozin itself?

No. It covers specified formulations containing dapagliflozin propylene glycol hydrate and methods of using those formulations. Compound protection is associated with separate SGLT2 inhibitor patents.

Can a generic avoid patent 8,361,972 by changing magnesium stearate?

Potentially, depending on the final formulation and claim construction. Magnesium stearate is expressly required in claim 1 and several dependent claims. Removing it or substituting another lubricant may avoid some claims, but the full formulation and method must be analyzed.

Does a Paragraph IV certification prove that the patent is invalid?

No. It is an ANDA applicant’s statutory assertion that the listed patent is invalid, unenforceable or not infringed. The assertion can lead to patent litigation but does not determine the result.

Does a method-of-use claim block sale of a generic tablet?

Not automatically. A method claim generally requires use of the product for the claimed treatment. A generic may reduce risk through labeling limitations, but formulation claims can remain independently relevant.

Is dapagliflozin propylene glycol hydrate the same as dapagliflozin?

No. Dapagliflozin identifies the active pharmaceutical ingredient, while dapagliflozin propylene glycol hydrate identifies a particular solid form or solvated form. That distinction is central to infringement and formulation design-around analysis.

References

AstraZeneca PLC. (2024). Annual report and Form 20-F. https://www.astrazeneca.com/investor-relations/annual-reports.html

U.S. Food and Drug Administration. (2024a). Approved drug products with therapeutic equivalence evaluations, commonly known as the Orange Book. https://www.accessdata.fda.gov/scripts/cder/ob/

U.S. Food and Drug Administration. (2024b). Abbreviated new drug application regulations and patent certifications. https://www.fda.gov/drugs/abbreviated-new-drug-application-anda/anda-submissions

U.S. Patent No. 6,515,117. (2003). C-aryl glucoside SGLT2 inhibitors. United States Patent and Trademark Office.

U.S. Patent No. 8,361,972. (2013). Pharmaceutical compositions comprising dapagliflozin propylene glycol hydrate. United States Patent and Trademark Office.

Drugs Protected by US Patent 8,361,972

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Patented / Exclusive Use	Submissiondate
Astrazeneca Ab	BYDUREON	exenatide synthetic	FOR SUSPENSION, EXTENDED RELEASE;SUBCUTANEOUS	022200-001	Jan 27, 2012		DISCN	Yes	No	8,361,972*PED				Y
Astrazeneca Ab	BYDUREON PEN	exenatide synthetic	FOR SUSPENSION, EXTENDED RELEASE;SUBCUTANEOUS	022200-002	Feb 28, 2014		DISCN	Yes	No	8,361,972*PED				Y
Astrazeneca Ab	BYDUREON BCISE	exenatide synthetic	SUSPENSION, EXTENDED RELEASE;SUBCUTANEOUS	209210-001	Oct 20, 2017		DISCN	Yes	No	8,361,972*PED				Y

International Family Members for US Patent 8,361,972

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
European Patent Office	2139494		PA2020522	Lithuania
European Patent Office	2139494		CA 2020 00035	Denmark
European Patent Office	2139494		301054	Netherlands