United States Patent 10,925,871: Sitagliptin Composition Claims, Patent Scope, and Generic-Entry Risk

US Patent 10,925,871 is directed to stable solid pharmaceutical compositions containing sitagliptin base, a selected organic acid or other pH-modifying agent, and less than 0.2% of a specified sitagliptin-related impurity. The independent claim combines composition limitations with a multi-stage granulation and tableting process.

The patent’s commercial relevance depends on whether a competing product uses sitagliptin base, falls within the claimed acid and pH ranges, contains the specified impurity below the stated threshold, and is manufactured using a process that meets the claim’s granulation sequence. The claims do not broadly cover all sitagliptin products, sitagliptin phosphate products, or all sitagliptin tablets.

What does US Patent 10,925,871 claim?

Claim 1 requires every one of the following elements:

Claim element	Required scope
Active ingredient	Sitagliptin base
Beneficial agent	A pH-modifying agent
Beneficial-agent concentration	About 1% to about 20% by weight
Composition pH	About pH 3 to about pH 8
Permitted pH agents	Gluconic, lactic, glycolic, ascorbic, malic, tartaric, tartronic, or mucic acid
Impurity limitation	Less than 0.2% by weight of impurity-I
Initial granulation	Sitagliptin base is mixed with excipients and granulated separately
Second granulation	The pH agent is mixed with excipients and granulated separately
Final processing	The two granule populations are blended and compressed into a tablet

The claim is therefore narrower than a conventional composition claim covering sitagliptin and an acid. It requires the specified impurity level and the claimed manufacturing sequence.

What is the claimed impurity?

The impurity is identified as:

3-Trifluoromethyl-5,6,7,8-tetrahydro-[1,2,4]triazolo[4,3-a]pyrazine hydrochloride

The claim calls this “impurity-I” and requires its concentration to be below 0.2% by weight of the finished composition. The impurity limitation can create a significant evidentiary issue because infringement analysis would require reliable analytical testing of the finished product or an equivalent batch specification.

A competitor may avoid literal infringement if the product contains the impurity at 0.2% or higher, assuming the measurement is valid and the claim’s “less than” threshold is not met. The opposite strategy may raise regulatory and quality concerns because deliberately increasing a specified process impurity may conflict with applicable impurity specifications.

How broad is claim 1 of US 10,925,871?

Claim 1 is a combination claim with multiple mandatory limitations. Its practical scope can be divided into four technical categories:

Active-form limitation: sitagliptin must be present as the base rather than necessarily as sitagliptin phosphate or another salt.
Acid and pH limitation: the formulation must contain one of eight listed agents at about 1% to about 20% by weight and produce a pH between about 3 and about 8.
Impurity limitation: impurity-I must be below 0.2% by weight.
Process limitation: sitagliptin-containing granules and beneficial-agent-containing granules must be formed separately, then blended and compressed.

A formulation that satisfies only the first two categories would not necessarily meet the literal language of claim 1. The process language materially limits the claim’s reach against products made by direct blending, single-step granulation, wet coating without the separate granulation sequence, or another manufacturing route.

Does “about” expand the claimed ranges?

The terms “about 1% to about 20%” and “about pH 3 to about pH 8” create ordinary claim-construction issues. Their scope depends on the specification, prosecution history, examples, measurement methods, and any disclaimer made during examination.

“About” does not automatically create an unlimited tolerance. Courts generally evaluate the term in its technical and patent-specific context. A product at 20.1% acid or pH 8.1 cannot be classified without considering the intrinsic record and the relevant measurement precision.

What do dependent claims 2 through 7 protect?

Claim	Added limitation	Commercial effect
2	Sitagliptin in amorphous form	Covers amorphous sitagliptin compositions that satisfy claim 1
3	Sitagliptin in crystalline form	Covers crystalline sitagliptin compositions that satisfy claim 1
4	Average particle size below 25 microns	Adds a particle-size limitation that may affect dissolution and content uniformity
5	Specified excipient categories	Covers formulations containing diluents, binders, disintegrants, glidants, lubricants, taste-masking agents, compression aids, colorants, flavors, or combinations
6	Solid dispersion	Adds a solid-dispersion structure
7	Malic acid	Narrows the pH-modifying agent to malic acid

Claims 2 and 3 are alternative dependent claims. A product cannot ordinarily be both amorphous and crystalline in the same relevant form unless the claim construction and analytical definition recognize a mixed or partially crystalline state.

Claim 4 is potentially important for formulation development because particle size below 25 microns may be common in an API process designed to improve dissolution. Its value depends on whether competing manufacturers use particle-size controls that fall below the threshold.

Claim 7 is the most commercially specific dependent claim. It may be relevant where malic acid is selected for stability, taste, pH control, or compatibility with a tablet process.

What formulations are protected by US 10,925,871?

The patent covers, at minimum, tablet formulations having:

Sitagliptin base;
One of the eight listed organic acids;
About 1% to about 20% of that acid;
A finished-composition pH of about 3 to about 8;
Less than 0.2% impurity-I;
Separate granulation of the sitagliptin and acid components;
Final blending and compression into a tablet.

The dependent claims extend the potential scope to amorphous sitagliptin, crystalline sitagliptin, sub-25-micron sitagliptin, broad excipient systems, solid dispersions, and malic-acid formulations.

Are sitagliptin phosphate products covered?

The claims as provided recite “sitagliptin base.” A product containing sitagliptin phosphate is not automatically within that limitation. The analysis would depend on whether the commercial dosage form contains the claimed base, converts to the base during processing or dissolution, or is legally treated as the claimed chemical form under the intrinsic patent record.

A sitagliptin phosphate product manufactured without the claimed separate-granulation sequence presents a further non-infringement position. That position would still require analysis of the actual formulation and process.

Are combination products such as sitagliptin/metformin covered?

The claims do not expressly require metformin. A sitagliptin/metformin product could fall within claim 1 if it also contains the required pH agent, impurity level, and claimed manufacturing process. Metformin is not excluded by the claim, but its presence alone does not establish infringement.

The claim’s excipient language in claim 5 does not expressly add metformin as an active pharmaceutical ingredient. A combination product must therefore be analyzed under claim 1 and any relevant construction of “composition comprising.”

How does the process limitation affect infringement?

Claim 1 requires a sequence involving two separately granulated material streams:

Sitagliptin base plus excipients are granulated.
The beneficial agent plus excipients are granulated separately.
The resulting granules are blended.
The blend is compressed into a tablet.

The phrase “with or without a binder solution” broadens the claim to both binder-assisted and binder-free granulation. Optional coating language also prevents a competitor from avoiding the claim merely by omitting a coating step.

A process may fall outside the literal claim if it uses:

Direct compression of a homogeneous powder blend;
One-step granulation of sitagliptin and the acid together;
A premixed acid-sitagliptin granulate;
Spray drying without the claimed separate granulation steps;
A capsule or sachet rather than a compressed tablet;
A different dosage-form manufacturing sequence.

Is this a product-by-process claim?

Claim 1 is drafted as a composition claim that includes process limitations. US courts generally treat process language in a product-by-process claim as limiting for infringement and patentability analysis. The Federal Circuit has held that a product made by a materially different process may avoid infringement where the claim requires the claimed process, although the treatment of process language depends on the exact claim structure and prosecution history. See Abbott Laboratories v. Sandoz, Inc., 566 F.3d 1282 (Fed. Cir. 2009); Amgen Inc. v. Sandoz Inc., 923 F.3d 1023 (Fed. Cir. 2019).

The process limitation is therefore a potential strength against a manufacturer using the same two-granule architecture. It is also a potential weakness because a competitor may design around the sequence while preserving the same acid, pH, impurity, and stability result.

How strong is the patent estate for US 10,925,871?

The supplied claims indicate a focused formulation patent rather than a basic composition-of-matter patent. Its strength is highest in the following circumstances:

Strength factor	Assessment
Technical specificity	High; the claims identify the active form, acid class, pH range, impurity threshold, and process
Ease of design-around	Moderate to high; competitors may alter the acid, pH, dosage form, granulation route, or sitagliptin form
Analytical enforceability	Moderate; impurity and pH testing are measurable, but sampling and method validation matter
Manufacturing relevance	High for products using separate granulation
Breadth against all sitagliptin products	Low; the claims do not cover every sitagliptin formulation
Relevance to sitagliptin base products	High if the formulation and process match
Relevance to sitagliptin phosphate products	Fact-dependent and potentially limited
Relevance to injectable products	Low based on the tablet-compression limitation
Relevance to direct-compression tablets	Potentially low unless the process limitation is met

The patent’s strongest enforcement theory is likely against a tablet manufacturer that independently reproduces the claimed formulation architecture and process. Its weakest position is against products using a different pH agent, a different dosage form, direct compression, a single combined granulation, or a different active form.

When does US Patent 10,925,871 lose exclusivity?

Patent expiration is generally calculated from the earliest effective nonprovisional US filing date, subject to patent-term adjustment, patent-term extension, terminal disclaimers, and other statutory adjustments. The grant date, February 23, 2021, does not itself determine the expiration date.

The effective expiration date must be taken from the patent’s front page and USPTO Patent Center record. A precise expiration date cannot be derived from the claim text alone. The relevant legal framework is 35 U.S.C. §§ 154 and 156.

The patent may also be subject to:

Patent-term adjustment for USPTO examination delay;
Terminal disclaimer against an earlier patent;
Patent-term extension for qualifying regulatory delay;
Post-grant correction or disclaimer;
Continuation or divisional relationships with separate claim scope.

A patent expiration date should therefore be distinguished from FDA exclusivity. FDA regulatory exclusivity attaches to an approved drug application, while US 10,925,871 is a formulation patent. The two periods can overlap or expire at different times.

What is the Orange Book status of US 10,925,871?

Orange Book listing cannot be inferred from the claim language. FDA generally lists patents submitted by an NDA holder that claim the approved drug, an approved method of using the drug, or a drug product or formulation meeting the applicable regulatory criteria. The listing process is governed principally by 21 C.F.R. § 314.53 and FDA’s Orange Book publication.

The claims here present several potential listing limitations:

They recite sitagliptin base rather than necessarily the approved sitagliptin phosphate active ingredient.
They require a particular formulation and manufacturing sequence.
They are directed to a tablet composition rather than a broad approved indication.
They do not, as supplied, claim a method of treating a disease.
They may not correspond to the formulation approved under the relevant sitagliptin NDA.

Accordingly, the patent’s Orange Book status must be established from the FDA patent-listing database and the relevant NDA records. The claim text alone does not establish that US 10,925,871 is listed against Januvia, Janumet, or another sitagliptin product.

What Paragraph IV risk does the patent create?

A generic applicant may submit a Paragraph IV certification if it asserts that a listed patent is invalid, unenforceable, or will not be infringed. If the patent is not listed for the relevant reference product, it ordinarily would not create a standard Orange Book Paragraph IV certification obligation for that product.

For a product designed to avoid the patent, the main non-infringement positions would be:

Use sitagliptin phosphate or another non-base form.
Select a pH modifier outside the eight listed acids.
Use a concentration outside the claimed range.
Use a formulation pH outside the claimed range.
Use a direct-compression or single-granulation process.
Manufacture a capsule, powder, liquid, or other non-tablet dosage form.
Exceed the claimed impurity threshold, subject to regulatory acceptability.
Use a particle size of 25 microns or greater to avoid claim 4.
Avoid a solid dispersion to avoid claim 6.
Avoid malic acid to avoid claim 7.

Invalidity arguments would likely focus on anticipation, obviousness, written description, enablement, indefiniteness, and the scope of the process limitations. A prior-art formulation containing sitagliptin base and one of the listed acids may not be enough by itself if it does not disclose the impurity threshold and separate-granulation process. Conversely, the claim may face obviousness scrutiny if the specification or prior art teaches pH adjustment and impurity reduction using conventional pharmaceutical excipients and granulation methods.

What patent litigation affects US 10,925,871?

The supplied claim text does not establish a litigation history, Paragraph IV complaint, settlement, license, or final judgment involving US 10,925,871. Litigation status should be verified through PACER, USPTO Patent Center, FDA Orange Book records, and publicly available settlement disclosures.

For commercial diligence, the relevant litigation questions are:

Issue	Business implication
Listed against an NDA	Determines whether a Paragraph IV certification is required
ANDA litigation filed	May trigger a 30-month stay under Hatch-Waxman
Claim-construction ruling	Determines the scope of “sitagliptin base,” “about,” and the process sequence
Preliminary injunction	Can delay launch before trial
Settlement agreement	May establish an authorized or licensed generic entry date
Terminal disclaimer	May align expiration with another patent
Inter partes review	May affect validity and enforcement timing
Covenant not to sue or license	Can reduce practical blocking value

No company can be identified as a confirmed challenger or licensee from the claim text alone.

How does this patent compare with the core sitagliptin patent landscape?

The sitagliptin patent landscape generally separates into four layers:

Patent layer	Typical protection	Relevance to US 10,925,871
Basic compound patents	Sitagliptin molecule and therapeutic use	Broadest historical protection; generally more important for original market entry
Salt and solid-form patents	Sitagliptin phosphate, hydrates, polymorphs, crystalline forms	May be more relevant to approved commercial API forms
Formulation patents	Stability, dissolution, impurity control, tablet architecture	US 10,925,871 falls principally in this category
Combination and method-of-use patents	Sitagliptin/metformin and diabetes-treatment methods	May create separate Orange Book or litigation exposure

Merck’s original sitagliptin compound patent, commonly identified as US 6,699,871, is part of the foundational sitagliptin landscape. Its expiration and any pediatric or patent-term adjustments are separate from the expiration of US 10,925,871. A generic manufacturer may clear the compound patent while still facing a formulation patent, or may design around the formulation patent while remaining blocked by a separate salt, polymorph, or use patent.

What generic launch scenarios exist?

Scenario 1: Same formulation and same process

This is the highest-risk scenario. A product using sitagliptin base, malic acid or another listed acid, the claimed pH range, low impurity-I, separate granulation, and tablet compression could implicate claim 1 directly.

Scenario 2: Same composition, different process

Risk depends heavily on construction of the process language. Direct compression or single-step granulation could provide a non-infringement position, but the manufacturing record must substantiate the alternative process.

Scenario 3: Sitagliptin phosphate formulation

This may reduce risk under the “sitagliptin base” limitation, but the full chemical and formulation record must be reviewed. Other sitagliptin salt or solid-form patents may become more important.

Scenario 4: Different acid

A formulation using citric acid, succinic acid, fumaric acid, or another non-listed pH modifier may avoid the literal closed Markush group in claim 1. The doctrine of equivalents could still be asserted, although the listed-acid limitation and prosecution history would be central.

Scenario 5: Non-tablet product

A capsule, oral solution, suspension, or powder product may avoid the compression limitation, although other patents and FDA product-equivalence requirements would apply.

Key Takeaways

US 10,925,871 is a narrow-to-moderate formulation patent focused on stable sitagliptin-base tablets.
Claim 1 requires a listed pH-modifying acid, about 1% to about 20% concentration, pH about 3 to about 8, impurity-I below 0.2%, and a separate two-granulation tableting process.
Claims 2 and 3 cover amorphous and crystalline sitagliptin alternatives.
Claim 4 adds sub-25-micron particle size; claim 6 adds solid dispersion; claim 7 specifically covers malic acid.
The process limitation may materially reduce infringement risk for direct-compression and single-granulation products.
The claims do not automatically cover all sitagliptin phosphate products, Januvia, Janumet, or every sitagliptin tablet.
Orange Book listing, patent expiration, litigation, settlement, and licensing status require record-level verification separate from the claim language.
The principal design-around routes are changing the sitagliptin form, pH agent, pH range, dosage form, granulation sequence, or solid-state architecture.

FAQs About US Patent 10,925,871

Does US 10,925,871 cover sitagliptin phosphate?

Not expressly based on the supplied claims. Claim 1 recites sitagliptin base. A sitagliptin phosphate product requires separate analysis of its chemical form, processing, and any conversion to the claimed base.

Is malic acid required in every claim?

No. Claim 1 permits eight pH-modifying agents. Claim 7 narrows the invention to malic acid.

Can a direct-compression tablet avoid claim 1?

Potentially. Claim 1 requires separate granulation of the sitagliptin-containing mixture and the beneficial-agent-containing mixture before blending and compression. A genuine direct-compression process may not satisfy that limitation.

Does the patent cover a sitagliptin/metformin tablet?

Potentially, but only if the combination product also satisfies the claim 1 limitations. Metformin is not itself required by the supplied claims.

What is the most important technical limitation for freedom-to-operate analysis?

The combined process and impurity limitations are likely the most discriminating. A competing product must be assessed not only by finished composition but also by API form, acid concentration, pH, impurity-I level, granulation sequence, and compression process.

References

United States Patent No. 10,925,871. (2021). Claims 1-7.
United States Patent and Trademark Office. (n.d.). Patent term adjustment and patent term extension provisions. 35 U.S.C. §§ 154, 156.
U.S. Food and Drug Administration. (n.d.). Approved drug products with therapeutic equivalence evaluations. Orange Book.
U.S. Food and Drug Administration. (n.d.). 21 C.F.R. § 314.53, submission of patent information.
Abbott Laboratories v. Sandoz, Inc., 566 F.3d 1282 (Fed. Cir. 2009).
Amgen Inc. v. Sandoz Inc., 923 F.3d 1023 (Fed. Cir. 2019).
United States Patent No. 6,699,871. (2004). Sitagliptin compound and related pharmaceutical applications.

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Patented / Exclusive Use	Submissiondate
Zydus Lifesciences	ZITUVIO	sitagliptin	TABLET;ORAL	211566-001	Oct 18, 2023		RX	Yes	No	10,925,871	⤷ Start Trial	Y				⤷ Start Trial
Zydus Lifesciences	ZITUVIO	sitagliptin	TABLET;ORAL	211566-002	Oct 18, 2023		RX	Yes	No	10,925,871	⤷ Start Trial	Y				⤷ Start Trial
Zydus Lifesciences	ZITUVIO	sitagliptin	TABLET;ORAL	211566-003	Oct 18, 2023		RX	Yes	Yes	10,925,871	⤷ Start Trial	Y				⤷ Start Trial
>Applicant	>Tradename	>Generic Name	>Dosage	>NDA	>Approval Date	>TE	>Type	>RLD	>RS	>Patent No.	>Patent Expiration	>Product	>Substance	>Delist Req.	>Patented / Exclusive Use	>Submissiondate

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
India	651MU2014	⤷ Start Trial
Philippines	12016501686	⤷ Start Trial
World Intellectual Property Organization (WIPO)	2015128877	⤷ Start Trial
South Africa	201606075	⤷ Start Trial
>Country	>Patent Number	>Estimated Expiration	>Supplementary Protection Certificate	>SPC Country	>SPC Expiration

Details for Patent: 10,925,871

Which drugs does patent 10,925,871 protect, and when does it expire?

Summary for Patent: 10,925,871