Details for Patent: 10,206,879

Which drugs does patent 10,206,879 protect, and when does it expire?

Patent 10,206,879 protects CRESEMBA and is included in one NDA.

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

This patent has eight patent family members in seven countries.

Summary for Patent: 10,206,879

Title:	Active ingredient containing stabilised solid forms and method for the production thereof
Abstract:	The invention relates to solid medicinal forms containing at least one active ingredient and at least one pharmaceutically compatible, water soluble drying agent which is selected from the group consisting of trimagnesium dicitrate and/or calcium chloride, the solid medicinal form having a drying loss of at most 6% and a relative equilibrium moisture content of 25% or less. The invention also relates to solid medicinal forms containing a moisture-sensitive active ingredient and trimagnesium dicitrate.
Inventor(s):	Peter Gruber, Dirk Spickermann
Assignee:	Astellas Pharma Inc
Application Number:	US15/705,599
Patent Litigation and PTAB cases:	See patent lawsuits and PTAB cases for patent 10,206,879
Patent Claim Types: see list of patent claims	Compound; Dosage form;

United States Patent 10,206,879: Claim Scope, Exclusivity, and Patent Landscape

U.S. Patent No. 10,206,879 protects a moisture-control formulation platform rather than a named drug. Independent claim 1 covers a non-effervescent dosage form in an HPMC capsule containing a moisture-sensitive active ingredient, trimagnesium dicitrate, and microcrystalline cellulose within specified weight ranges and moisture limits. The claim excludes trimagnesium dicitrate as the active ingredient but does not identify any other API.

The patent's commercial significance depends on whether an approved product uses all of the following features: an HPMC capsule, the claimed composition ranges, the claimed drying-loss and equilibrium-moisture limits, and, for dependent claims, the specified excipients, packaging, or dry-granulation process. The claims do not by themselves establish coverage of a particular marketed drug, Orange Book listing, patent expiration date, Paragraph IV dispute, license, or settlement.

What does U.S. Patent 10,206,879 protect?

The patent protects a solid oral formulation designed to stabilize a moisture-sensitive active ingredient against hydrolysis during storage.

The core claimed architecture is:

Claim element	Requirement in claim 1
Dosage form	Non-effervescent solid medicinal form
Capsule	HPMC capsule
Active ingredient	Moisture-sensitive active ingredient other than trimagnesium dicitrate
Active ingredient loading	30% to 40% by weight of the capsule filling
Drying agent	Trimagnesium dicitrate
Trimagnesium dicitrate loading	20% to 50% by weight of the capsule filling
Filler	Microcrystalline cellulose
Microcrystalline cellulose loading	5% to 30% by weight of the capsule filling
Drying loss	0.5% to 2.5%, measured at 120°C for 30 minutes
Relative equilibrium moisture	No more than 15% at 25°C

The claim uses “comprising,” which generally makes it open-ended. A product can contain additional excipients and still fall within claim 1 if it includes every recited limitation. The open-ended language does not eliminate the requirement that the named ingredients and measured properties fall within the stated ranges.

How do claims 2 through 8 narrow the patent scope?

Claims 2 through 8 add formulation, packaging, and manufacturing limitations.

Claim	Added limitation	Commercial relevance
2	Microcrystalline cellulose is 10% to 20% by weight	Narrows the filler range
3	Relative equilibrium moisture is no more than 10% at 25°C	Adds a stricter moisture-performance threshold
4	Stearic acid is 0.3% to 2% by weight	Covers a lubricant-containing formulation
5	Stearic acid is 1% to 2% by weight	Narrower stearic-acid range
6	Silica is 0.2% to 2% by weight	Covers a silica-containing formulation
7	External drying agent and tight, substantially water-impermeable packaging	Extends the claimed system to packaging and desiccation
8	Active ingredient and trimagnesium dicitrate are dry granulated together	Adds a process limitation

Claims 4 and 5 overlap. A formulation containing 1% to 2% stearic acid falls within both claims, assuming it also meets claim 1. Claim 5 is narrower because it excludes formulations containing 0.3% to less than 1% stearic acid.

Claim 7 is important for products sold in bottles, blisters, or other moisture-controlled packaging. It requires more than a desiccant somewhere in the supply chain. The packaging must be “tight” and “substantially impermeable to water,” and the product must be packaged together with an external drying agent.

Claim 8 creates a manufacturing-process limitation. A formulation that contains the same ingredients but uses direct blending, wet granulation, or separate granulation may avoid claim 8 while remaining within claim 1.

What is the likely scope of the independent claim?

Claim 1 is a multi-variable formulation claim. A potentially infringing product must satisfy every required category:

1. It must be a solid medicinal form.
2. It must be non-effervescent.
3. It must use an HPMC capsule.
4. The API must be moisture-sensitive.
5. The API must be present at 30% to 40% by weight of the capsule filling.
6. Trimagnesium dicitrate must be present at 20% to 50%.
7. Microcrystalline cellulose must be present at 5% to 30%.
8. Drying loss must be 0.5% to 2.5% under the stated test.
9. Relative equilibrium moisture must be no more than 15% at 25°C.

The claim is therefore narrower than a general claim to using trimagnesium dicitrate as a desiccant. It does not cover every tablet, capsule, or powder containing magnesium citrate. It also does not cover every HPMC capsule containing a moisture-sensitive drug.

The word “comprising” creates latitude for additional materials, but the numerical limitations remain material. A competitor cannot rely solely on adding an unclaimed excipient if the finished product still satisfies the recited ranges and moisture tests.

Does the claim cover a specific drug?

No specific drug is identified in the supplied claims.

The phrase “a moisture-sensitive active ingredient” is functional and generic. The exclusion of trimagnesium dicitrate indicates that the magnesium salt is intended to operate as the drying agent rather than as the claimed active ingredient. The claim could potentially read on multiple moisture-sensitive small-molecule APIs, subject to the other limitations.

This breadth creates two competing characteristics:

• The claim has platform potential because it is not limited to one named API.
• The claim may face written-description, enablement, anticipation, or obviousness challenges if the specification does not adequately support the full range of moisture-sensitive active ingredients and the claimed performance results.

The patent specification, prosecution history, cited references, and any terminal disclaimer would be necessary to evaluate those issues conclusively. The claim text alone establishes the boundaries of the issued claims, not the full validity position.

What formulations are protected by the patent?

The strongest coverage applies to HPMC capsules using a relatively high loading of moisture-sensitive API and trimagnesium dicitrate as a drying agent.

Formulations within the apparent claim architecture

A formulation is structurally positioned for claim coverage when it has:

• 30% to 40% API;
• 20% to 50% trimagnesium dicitrate;
• 5% to 30% microcrystalline cellulose;
• no effervescence;
• an HPMC capsule shell;
• drying loss of 0.5% to 2.5%; and
• relative equilibrium moisture of 15% or less.

The dependent claims increase exposure where the product also contains:

• 10% to 20% microcrystalline cellulose;
• 0.3% to 2% stearic acid;
• 1% to 2% stearic acid;
• 0.2% to 2% silica;
• an external desiccant; or
• a dry-granulation step combining the API and trimagnesium dicitrate.

Formulations that may fall outside claim 1

A product may avoid literal claim 1 if it uses:

• a gelatin capsule instead of HPMC;
• less than 30% or more than 40% API;
• less than 20% or more than 50% trimagnesium dicitrate;
• no microcrystalline cellulose;
• relative equilibrium moisture above 15%;
• drying loss below 0.5% or above 2.5%; or
• an effervescent dosage form.

A design-around based on moisture values carries analytical risk because test conditions, sampling, equilibration time, batch variability, and laboratory method can affect the result. The patent expressly defines the temperature and, for drying loss, the test duration, but the supplied claim does not provide the full analytical protocol.

How should the weight percentages be interpreted?

The percentages are stated as percentages by weight of the “capsule filling,” not necessarily of the complete dosage form including the HPMC shell.

This distinction matters. The capsule shell is excluded from the formulation denominator if the claim language is applied literally. A product can therefore have a different percentage by total capsule weight while still meeting the claim based on the fill weight.

The recited ranges also overlap in a way that requires formulation-specific analysis. The minimum listed amounts in claim 1 total 55% of the capsule filling before optional excipients. The maximum amounts total 120%. Because the claim uses “comprising,” the ranges should be read as allowable individual ranges, but a physical formulation still cannot exceed 100% of the relevant filling weight. The practical scope is the portion of the multidimensional range that can coexist in a real formulation.

What is the patent’s technical point?

The technical point is moisture management through a combination of:

• an HPMC capsule;
• trimagnesium dicitrate as an internal drying agent;
• microcrystalline cellulose as a carrier or filler;
• controlled water content;
• optional stearic acid and silica;
• external desiccation; and -, in claim 8, dry granulation of the API with trimagnesium dicitrate.

The claims do not merely require a low-moisture product. They require a particular formulation structure coupled with moisture-performance results. This gives the patent both composition and product-property characteristics.

The performance limitations may strengthen infringement proof if validated by reproducible testing. They may also create validity and enforcement issues if the measurements are sensitive to test protocol or if the specification does not disclose adequate methods across the full claim scope.

How strong is the patent estate for U.S. Patent 10,206,879?

Based on the supplied claims, the issued U.S. estate appears concentrated in one formulation patent with eight claims. Its practical strength depends on five factors:

Factor	Assessment from the claims
API breadth	Broad because no API is named
Dosage-form breadth	Narrow because HPMC and non-effervescent solid requirements apply
Composition breadth	Moderate; several ingredients have broad overlapping ranges
Product-property limitations	Narrowing and potentially difficult to reproduce
Manufacturing coverage	Limited to dry granulation in claim 8

The estate is stronger against a product that copies the same capsule platform and manufacturing approach. It is weaker against products using different capsule materials, different fillers, different drying agents, or moisture-control methods that produce values outside the claimed ranges.

A platform claim can have high strategic value even without naming a drug, but its enforceability depends on whether the patent specification supports the breadth of the generic active-ingredient language. The claim's exclusion of trimagnesium dicitrate as the active ingredient also reduces the possibility that the patent covers magnesium citrate products in which the salt itself is the therapeutic API.

When does U.S. Patent 10,206,879 lose exclusivity?

The patent issued on February 19, 2019. The ordinary U.S. patent term is generally 20 years from the earliest effective nonprovisional filing date, subject to patent-term adjustment, patent-term extension, terminal disclaimers, and applicable priority claims under 35 U.S.C. § 154.[1]

The issue date alone does not establish the expiration date. A precise expiration calculation requires the patent's effective filing and priority history, any continuation or divisional relationship, patent-term adjustment, and terminal-disclaimer data. The claims supplied do not contain those details.

The patent does not receive biologic exclusivity merely because it covers a medicinal product. Any FDA regulatory exclusivity would attach to the approved product and its regulatory history, not automatically to the formulation patent.

What is the Orange Book status of U.S. Patent 10,206,879?

The claims alone do not establish an Orange Book listing.

The FDA Orange Book identifies patents and exclusivity associated with approved drug products. A formulation patent may be listed when it claims an approved drug product, a formulation, or an approved method of use and satisfies FDA listing requirements.[2] Because the patent does not identify a named active ingredient or approved product in the supplied material, no product-specific Orange Book conclusion follows from the claims.

If the patent is listed for an approved drug, the relevant listing would typically be evaluated against the drug's NDA, dosage form, formulation, and labeling. A generic applicant could then address the patent through a Paragraph III certification, Paragraph IV certification, or other applicable certification under the Hatch-Waxman framework.[3]

Are Paragraph IV challenges or generic-launch disputes associated with this patent?

No Paragraph IV litigation, generic challenger, settlement, or launch date is established by the supplied information.

For a generic capsule to face a Paragraph IV issue, the patent would first need to be listed for the relevant reference-listed drug. The applicant would then need to determine whether its proposed product is covered by the listed claims and whether those claims are invalid, unenforceable, or not infringed.

The most likely technical challenge points would be:

• whether the proposed capsule is actually made from HPMC;
• whether the API qualifies as moisture-sensitive;
• whether the API and excipient percentages are calculated using the same capsule-filling denominator;
• whether trimagnesium dicitrate functions as the claimed drying agent;
• whether the product meets the drying-loss range;
• whether relative equilibrium moisture is no more than 15%; and
• whether the formulation is non-effervescent.

A generic could seek to avoid infringement through a different capsule shell, a different desiccant, a different filler, or a formulation outside the numerical ranges. It could also contest validity based on prior art combinations involving moisture-sensitive APIs, magnesium salts, cellulose excipients, HPMC capsules, and desiccant packaging.

Does biosimilar risk apply to this patent?

Biosimilar risk is generally not the relevant framework for this patent.

The claimed product is a solid HPMC capsule containing a conventional pharmaceutical active ingredient and excipients. That profile is consistent with a small-molecule drug, for which generic competition proceeds under the ANDA pathway rather than the biosimilar pathway. The Biologics Price Competition and Innovation Act applies to biological products, not ordinary small-molecule capsule formulations.[4]

If an active ingredient covered by the claim were later treated as a biological product, the analysis would depend on the product's regulatory classification. The claim language itself does not create biosimilar exclusivity.

What manufacturing and packaging barriers does the patent create?

The patent may create barriers at three stages.

Formulation development

A competing developer must control the API, trimagnesium dicitrate, and microcrystalline cellulose within the claimed ranges. The developer must also determine whether its formulation's moisture values fall within the claimed windows.

Process development

Claim 8 may create additional exposure where the API and trimagnesium dicitrate are dry granulated together. A different granulation sequence may reduce risk, but the formulation could still fall within claim 1.

Commercial packaging

Claim 7 reaches products packaged with an external drying agent in tight, water-resistant packaging. A product using a bottle desiccant or another external moisture-control system requires a packaging-specific infringement review.

The patent's packaging limitation may have particular relevance for products that need long shelf life under ordinary distribution conditions. It is less relevant to products sold in packaging without an external drying agent, although those products may still satisfy claim 1.

How does this patent compare with a conventional drug-specific formulation patent?

Issue	U.S. Patent 10,206,879	Drug-specific formulation patent
API identification	Generic moisture-sensitive API	Usually names one API
Platform breadth	Potentially broad across APIs	Narrower by API
Product identification	Requires claim charting against formulation properties	Easier to map to a marketed product
Infringement proof	Requires composition and moisture testing	Often focuses on formulation composition
Validity exposure	Breadth may create enablement and written-description issues	Drug-specific disclosure may be easier to support
Orange Book analysis	Product connection is not apparent from claims	Usually more direct
Generic design-around	Capsule, excipient, moisture, or process changes	Often requires a different formulation

The patent is best viewed as a formulation-platform asset. Its commercial value depends on whether a commercially important product uses the claimed combination, not simply on the breadth of the phrase “moisture-sensitive active ingredient.”

What geographic coverage does the patent provide?

U.S. Patent 10,206,879 provides U.S. patent rights only. Equivalent protection in Europe, Japan, China, Canada, or other jurisdictions would require separate national or regional patent rights in the same family.

The supplied claims do not identify foreign counterparts, priority filings, national-stage applications, granted foreign patents, or pending continuations. Geographic freedom-to-operate cannot be inferred from the U.S. patent number alone.

A global landscape should separately examine:

• PCT publications;
• European regional applications;
• national-phase cases;
• continuation and divisional applications;
• granted foreign counterparts;
• terminal disclaimers;
• abandoned applications; and
• jurisdiction-specific claim amendments.

What licensing deals or settlements affect the patent?

No license, covenant not to sue, co-development agreement, Paragraph IV settlement, or other commercial resolution is established by the supplied claims.

Patent ownership and licensing must be distinguished. The assignee shown in the official patent record may not be the current owner, exclusive licensee, or party entitled to enforce the patent. Assignment records and litigation dockets are required to establish those relationships.

What is the practical generic-entry risk?

The risk is highest for a generic product that deliberately replicates the claimed moisture-control architecture:

• HPMC capsule;
• 30% to 40% moisture-sensitive API;
• 20% to 50% trimagnesium dicitrate;
• 5% to 30% microcrystalline cellulose;
• low drying loss;
• equilibrium moisture of 15% or less;
• optional external desiccant packaging; and
• dry granulation of the API with trimagnesium dicitrate.

The risk is lower where the generic uses a hard-gelatin capsule, a different drying agent, a lower trimagnesium dicitrate concentration, a different filler, or a moisture profile outside the claim. A design-around based only on changing an optional excipient may be inadequate because claim 1 is open-ended.

Key Takeaways

• U.S. Patent 10,206,879 is a moisture-control formulation patent, not a drug-specific patent based on the supplied claims.
• Claim 1 requires an HPMC capsule, a moisture-sensitive API other than trimagnesium dicitrate, trimagnesium dicitrate, microcrystalline cellulose, defined loading ranges, and two moisture-related performance limits.
• Claims 2 through 8 add narrower limits for cellulose, moisture, stearic acid, silica, packaging, and dry granulation.
• The claims use “comprising,” so additional excipients do not necessarily avoid infringement.
• No specific active ingredient, approved product, Orange Book listing, Paragraph IV challenge, biosimilar dispute, license, or settlement is established by the claim text.
• The patent issued February 19, 2019, but its expiration date cannot be calculated from the claims alone.
• Generic design-around options include changing the capsule shell, drying agent, filler, formulation ranges, moisture profile, packaging, or granulation process.
• The strongest commercial exposure is for products that copy the full HPMC, trimagnesium dicitrate, microcrystalline cellulose, and low-moisture combination.

FAQs

Can a product infringe if it uses trimagnesium citrate but not trimagnesium dicitrate?

Literal infringement would depend on whether the material is legally and chemically the claimed trimagnesium dicitrate. A different magnesium citrate salt may provide a design-around, but equivalence and claim-construction issues would require a product-specific analysis.

Does a product infringe claim 1 if it uses a gelatin capsule with the same powder filling?

A gelatin capsule would not literally satisfy the HPMC capsule limitation. Claims 2 through 8 depend on claim 1 and would ordinarily carry the same capsule limitation.

Is the 15% equilibrium-moisture limit measured on the powder or the complete capsule?

The claim text supplied does not specify the precise sampling object or analytical protocol. The patent's specification and prosecution history would control the construction and testing methodology.

Can claim 8 be avoided by dry granulating the ingredients separately?

Potentially, because claim 8 requires the active ingredient and trimagnesium dicitrate to be dry granulated together. Separate granulation may avoid claim 8, but it does not necessarily avoid claim 1.

Does the patent block all moisture-sensitive drug formulations?

No. The patent does not claim every moisture-sensitive formulation. It requires the specific HPMC capsule, ingredient ranges, non-effervescent form, and moisture-performance limits recited in claim 1.

References

1. United States Patent and Trademark Office. (2024). 35 U.S.C. § 154: Contents and term of patent; provisional rights. https://www.uspto.gov/web/offices/pac/mpep/consolidated_laws.pdf
2. U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations: Orange Book. https://www.fda.gov/drugs/drug-approvals-and-databases/orange-book
3. United States Code. (2024). 21 U.S.C. § 355(j): Abbreviated new drug applications and patent certifications. https://uscode.house.gov/view.xhtml?req=granuleid:USC-prelim-title21-section355
4. U.S. Food and Drug Administration. (2024). Biosimilar and interchangeable products. https://www.fda.gov/drugs/biosimilars/biosimilar-and-interchangeable-products
5. United States Patent and Trademark Office. (2019). U.S. Patent No. 10,206,879. https://patents.google.com/patent/US10206879B2/en

Drugs Protected by US Patent 10,206,879

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Patented / Exclusive Use	Submissiondate
Astellas	CRESEMBA	isavuconazonium sulfate	CAPSULE;ORAL	207500-002	Nov 22, 2022		RX	Yes	No	10,206,879*PED				Y
Astellas	CRESEMBA	isavuconazonium sulfate	CAPSULE;ORAL	207500-001	Mar 6, 2015		RX	Yes	Yes	10,206,879*PED				Y

Foreign Priority and PCT Information for Patent: 10,206,879

Foriegn Application Priority Data
Foreign Country	Foreign Patent Number	Foreign Patent Date
	06020008	Sep 25, 2006

International Family Members for US Patent 10,206,879

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Austria	E459342
Australia	2007302320
Canada	2663941