United States Patent 8,735,380: Ulipristal Acetate Tablet Claims, Scope and Patent Landscape

U.S. Patent No. 8,735,380 protects specific immediate-release oral tablet formulations containing ulipristal acetate, not ulipristal acetate as a molecule or every tablet containing the drug. The core combination requires defined ranges for ulipristal acetate, diluent, croscarmellose sodium and magnesium stearate, together with a rapid-dissolution result in an acidic paddle assay. Claim 18 is the commercially most important formulation claim because it identifies a narrow composition based on microcrystalline cellulose, mannitol, croscarmellose sodium, talc and magnesium stearate.

The patent creates formulation risk for a generic 5 mg, 10 mg, 15 mg or 30 mg ulipristal acetate tablet when the proposed product uses the claimed excipient architecture and meets the dissolution limitation. It does not create a broad monopoly over emergency contraception or over all oral ulipristal acetate products.

What does U.S. Patent 8,735,380 protect?

The patent claims an oral pharmaceutical tablet with five central elements:

Ulipristal acetate at 3% to 18% by weight and 1 mg to 50 mg per tablet.
A diluent selected from lactose monohydrate, microcrystalline cellulose, mannitol or combinations thereof, at 60% to 95% by weight.
Croscarmellose sodium at 1% to 10% by weight.
Magnesium stearate at 0.5% to 5% by weight.
At least 80% dissolution of the ulipristal acetate within approximately 20 minutes at 37°C and pH 1 in a paddle apparatus.

The claim is therefore a composition-and-performance claim. A product must satisfy both the compositional limitations and the dissolution limitation to fall within literal claim 1.

Claim element	Independent-claim requirement
Dosage form	Oral tablet
Ulipristal acetate	3-18 wt%; 1-50 mg
Diluent	60-95 wt%
Permitted diluent	Lactose monohydrate, microcrystalline cellulose, mannitol, or combinations
Binding agent	0-10 wt%
Croscarmellose sodium	1-10 wt%
Magnesium stearate	0.5-5 wt%
Dissolution	At least 80% in about 20 minutes
Test conditions	Paddle apparatus, 37°C ± 0.5°C, pH 1

The patent does not require a particular manufacturing process in the claims provided. It also does not require a coating, a particular tablet weight, a particular hardness, a particular granulation method or a particular particle-size distribution.

How do claims 2 through 18 narrow the patent scope?

Claims 2 through 17 narrow the formulation by adding quantitative, excipient, dosage-form or manufacturing-related restrictions. Claim 18 is the narrowest and most commercially specific formulation claim.

Claim	Added limitation
2	Binding agent at 1-10 wt%
3	Diluent at 65-92 wt%
4	Binding agent at 1.5-8.5 wt%
5	Croscarmellose sodium at 1.5-8.5 wt%
6	Magnesium stearate at 0.5-4 wt%
7	Ulipristal acetate at 5-30 mg
8	Ulipristal acetate at 5, 10 or 15 mg
9	Binding agent is a polymer
10	Binding agent is hydroxypropyl methylcellulose or povidone
11	Lactose monohydrate plus povidone
12	Microcrystalline cellulose as diluent
13	Microcrystalline cellulose plus mannitol
14	Microcrystalline cellulose plus talc
15	Microcrystalline cellulose formulation without binding agent
16	Microcrystalline cellulose and mannitol, without binding agent
17	Uncoated tablet
18	Specific quantitative microcrystalline cellulose/mannitol formulation with talc

Claim 18 recites approximately:

6.7 wt% ulipristal acetate
61 wt% microcrystalline cellulose
27 wt% mannitol
1.7 wt% croscarmellose sodium
2.6 wt% talc
1 wt% magnesium stearate

These percentages total approximately 100%. The claim does not expressly recite a binding agent, which is consistent with the claim 16 pathway requiring a formulation devoid of a binding agent.

What is the practical scope of claim 1?

Claim 1 is broader than claim 18 but remains formulation-specific. A competing tablet may avoid literal infringement by changing one or more of the following:

Using a diluent outside the listed group.
Reducing croscarmellose sodium below 1 wt% or eliminating it.
Using a different lubricant instead of magnesium stearate.
Using a non-tablet oral dosage form.
Using a formulation that does not achieve the claimed dissolution result.
Moving ulipristal acetate outside the 3-18 wt% range.
Using more than 50 mg or less than 1 mg of ulipristal acetate.

The dissolution limitation is commercially important. A generic developer cannot assess infringement from the formula alone. The finished dosage form must be tested under the specified acidic dissolution conditions. A formulation outside the literal range may still face a doctrine-of-equivalents argument, but substantial quantitative departures generally improve design-around position.

The word "about" in "within about 20 minutes" introduces a claim-construction issue. The more objective limitation is the requirement that at least 80% of the active ingredient be dissolved under defined apparatus, temperature and pH conditions. Method validation, sampling intervals, agitation speed and the definition of the dissolution endpoint may become important in litigation.

Which formulation features create the highest infringement risk?

The highest-risk formulation is one that resembles claim 18 and satisfies the dissolution limitation. The following profile is particularly exposed:

Product characteristic	Risk assessment
5, 10 or 15 mg ulipristal acetate	High under claim 8
Microcrystalline cellulose	High under claims 1, 12, 15, 16 and 18
Mannitol with microcrystalline cellulose	High under claims 13, 16 and 18
Croscarmellose sodium around 1.7 wt%	High under claims 1, 5 and 18
Magnesium stearate around 1 wt%	High under claims 1, 6 and 18
Talc around 2.6 wt%	Relevant to claims 14 and 18
No binding agent	High under claims 15, 16 and 18
Uncoated tablet	Relevant under claim 17
At least 80% dissolution in 20 minutes at pH 1	Critical to claim 1 and all dependent claims

A product using lactose monohydrate and povidone presents a separate risk under claim 11. A product using hydroxypropyl methylcellulose or povidone as a polymeric binder may fall within claims 9 and 10 if the remaining claim 1 requirements are met.

When does U.S. Patent 8,735,380 lose exclusivity?

U.S. Patent No. 8,735,380 issued on May 27, 2014. The patent concerns a pharmaceutical formulation and is associated with the ulipristal acetate product marketed as ella. The ordinary patent-term framework is 20 years from the earliest effective nonprovisional or international filing date, subject to patent-term adjustment, patent-term extension and terminal-disclaimer issues.[1]

The patent's enforceable expiration date should be taken from the current USPTO patent record and any applicable patent-term calculation. The issue date alone does not establish the expiration date. A priority date or publication date also does not, by itself, establish the enforceable term.

For commercial planning, the relevant distinction is:

Exclusivity type	Relevance to this patent
Patent term	Controls enforceability of the formulation claims
FDA chemical exclusivity	Applies to the active ingredient regulatory product, not automatically to this formulation patent
Orphan exclusivity	Not relevant to ulipristal acetate emergency contraception
Pediatric exclusivity	Could extend listed FDA protections if granted
Regulatory exclusivity	Separate from the patent term
Orange Book listing	Determines whether an ANDA applicant must address listed patents

A generic entrant can obtain FDA approval after regulatory exclusivity expires but still face a patent block if a listed patent remains enforceable.

What is the FDA and Orange Book status of the ulipristal acetate product?

Ulipristal acetate 30 mg was approved by the FDA as ella under NDA 022474 for emergency contraception.[2] The product is an oral tablet. The FDA-approved label identifies ulipristal acetate as a selective progesterone receptor modulator and directs administration of a single 30 mg tablet.[3]

The Orange Book status must be assessed by NDA, patent number, use code and current annual or cumulative supplement listing. U.S. Patent 8,735,380 is a formulation patent. Its presence in the Orange Book, if listed, would not necessarily block every ulipristal acetate ANDA. The impact would depend on:

Whether the patent is listed against NDA 022474.
The patent's use code and listed claims.
Whether the ANDA product uses the claimed formulation.
Whether the ANDA applicant files a Paragraph IV certification.
Whether the patent holder brings suit within the statutory period.

An Orange Book listing does not establish infringement. It creates a regulatory patent-certification pathway and can trigger a 30-month stay if the statutory conditions are satisfied.[4]

Are there Paragraph IV challenges to this patent?

A Paragraph IV challenge is an ANDA certification that a listed patent is invalid, unenforceable or will not be infringed by the proposed generic product. The supplied claims do not establish whether a particular ANDA applicant has filed a Paragraph IV certification against U.S. Patent 8,735,380.

For this patent, a Paragraph IV case would likely focus on:

Anticipation by earlier ulipristal acetate tablet formulations.
Obviousness based on conventional excipient selection and dissolution optimization.
Written-description and enablement issues across the claimed concentration ranges.
Indefiniteness of "about 20 minutes."
Whether the proposed generic product satisfies the pH 1 dissolution limitation.
Whether the patent is properly listed for the approved product and indication.
Whether any terminal disclaimer or prosecution-history limitation affects enforceability.

The strongest invalidity theory would likely be obviousness if prior art disclosed ulipristal acetate tablets with common diluents, disintegrants and lubricants and provided a motivation to achieve rapid dissolution. The strongest infringement defense would be failure to meet the dissolution limitation or omission of one required excipient.

How strong is the patent estate for ulipristal acetate?

The patent estate is stronger against close formulation copies than against materially different dosage forms. The claim structure provides several layers of protection, but most layers depend on the same core combination.

Estate characteristic	Assessment
Molecule protection	Not provided by the supplied claims
Broad oral-product protection	Limited
Immediate-release tablet protection	Meaningful
Excipient-specific protection	Meaningful
Dissolution-based protection	Potentially valuable but testing-sensitive
Protection of claim 18 formulation	Narrow and commercially targeted
Process protection	Not present in the supplied claims
Injectable or transdermal protection	Not present
Biosimilar relevance	None, because ulipristal acetate is a small molecule
Design-around flexibility	Moderate to high

The patent is best characterized as a formulation patent with moderate blocking power. It can delay or complicate a generic launch that closely follows the reference product's excipient system. It is less likely to block a generic using a different diluent, disintegrant, lubricant or release profile.

What generic launch scenarios exist?

Scenario 1: Close-copy tablet

A generic product reproduces the microcrystalline cellulose/mannitol formulation, uses croscarmellose sodium and magnesium stearate, and meets the dissolution threshold. This is the highest litigation-risk scenario. The applicant would likely need a Paragraph IV strategy if the patent is listed and remains enforceable.

Scenario 2: Formula outside the claimed ranges

A generic may alter excipient percentages so that one or more concentration limitations are not met. This may reduce literal infringement risk, but the product must still satisfy FDA quality and bioequivalence requirements.

Scenario 3: Alternative excipient system

Replacing the listed diluents or using a different disintegrant and lubricant provides a stronger design-around position. The developer must account for ulipristal acetate's formulation properties and the need for acceptable dissolution and bioavailability.

Scenario 4: Different dosage form

A capsule, suspension or other oral dosage form may avoid the tablet claims. FDA approval, however, may require a different regulatory showing and may not qualify as a conventional ANDA substitutable for the reference listed drug.

Scenario 5: Post-expiration launch

A generic can launch without patent infringement exposure after all relevant formulation patents expire, are invalidated or are otherwise unenforceable. Regulatory exclusivity and other listed patents may still affect timing.

Does biosimilar risk apply to ulipristal acetate?

No. Ulipristal acetate is a chemically synthesized small molecule, not a biologic. The relevant competitive pathway is an ANDA for a generic drug, not a biosimilar application under the Public Health Service Act. The principal regulatory issues are pharmaceutical equivalence, bioequivalence, labeling, patent certification and substitutability.[2,4]

What manufacturing and intellectual-property barriers remain?

The claims do not expressly require wet granulation, dry granulation, direct compression or a particular order of addition. Manufacturing risk therefore arises indirectly from the need to produce a tablet that satisfies the composition and dissolution limitations.

Important technical variables include:

Particle size and polymorphic form of ulipristal acetate.
Blend uniformity at low active concentration.
Lubrication time and magnesium stearate distribution.
Compression force and tablet porosity.
Croscarmellose sodium level and disintegration behavior.
Mannitol and microcrystalline cellulose grade.
Talc concentration and blending conditions.
Dissolution sampling and assay methodology.

A generic can design around the claim while still encountering development barriers. Ulipristal acetate content uniformity, dissolution performance and stability can constrain excipient substitutions.

What licensing and litigation conclusions follow?

The supplied claim set does not establish a licensing transaction, settlement agreement or active litigation involving U.S. Patent 8,735,380. The commercial diligence conclusion is narrower: any license covering ella or ulipristal acetate should be reviewed for formulation-patent rights, territory, field of use, sublicensing, authorized-generic rights and obligations triggered by an ANDA Paragraph IV challenge.

The relevant rights may be held by the patent owner, the NDA sponsor or a successor commercial entity. Patent ownership and FDA sponsorship are separate questions. A change in product commercialization does not automatically change patent ownership or Orange Book listing status.

How does U.S. Patent 8,735,380 compare with broader ulipristal acetate patents?

U.S. Patent 8,735,380 should be separated from patents covering:

The ulipristal acetate compound itself.
Emergency contraception methods.
Treatment of uterine fibroids.
Dosing regimens.
Crystalline forms or polymorphs.
Manufacturing processes.
Other dosage forms.

A competitor may avoid this patent while remaining exposed to a method-of-use, active-ingredient, crystalline-form or process patent. A complete freedom-to-operate opinion therefore requires a family-level search across U.S., European and international patent records, plus current FDA and court records.

Key Takeaways

U.S. Patent 8,735,380 is a formulation patent for oral ulipristal acetate tablets.
Claim 1 requires specific excipient classes, concentration ranges and rapid dissolution at pH 1.
Claim 18 targets a narrow microcrystalline cellulose/mannitol formulation with talc and no binding agent.
The patent does not claim ulipristal acetate generally, all emergency-contraception products or every oral dosage form.
A close copy of the ella tablet presents the highest infringement risk.
Alternative excipients, altered concentration ranges, different dissolution behavior or a non-tablet dosage form can provide design-around routes.
Ulipristal acetate is a small molecule, so generic ANDA risk applies rather than biosimilar risk.
Orange Book listing, patent term, Paragraph IV activity and litigation status must be evaluated separately from the wording of the claims.
The patent's commercial strength is moderate: meaningful against close formulation copies, but narrower than molecule or method-of-use protection.

FAQs

Is U.S. Patent 8,735,380 a patent on ella?

It is a formulation patent relevant to oral ulipristal acetate tablets, including products comparable to ella. The claims provided do not establish that every ella-related product or every ulipristal acetate product infringes.

Does a 30 mg ulipristal acetate tablet automatically infringe?

No. A 30 mg tablet may fall outside claim 8, which is limited to 5, 10 or 15 mg, but it can still implicate claim 1 if the required percentages, excipients and dissolution performance are present.

Can a generic avoid the patent by changing only the tablet coating?

Not necessarily. Claim 1 requires an oral tablet but does not require a coating. An uncoated product is expressly addressed by claim 17, but changing coating status alone may not avoid the independent claim.

Does using povidone create patent risk?

Yes, if the product otherwise satisfies claim 1 and uses lactose monohydrate with povidone, claim 11 may apply. Povidone may also be relevant under claims 9 and 10 as a polymeric binding agent.

Does a different dissolution medium avoid infringement?

Potentially, but only if the marketed product does not meet the specified claim assay. Testing must address the patent's defined pH, temperature, apparatus and dissolution endpoint. A different release specification alone does not establish noninfringement.

References

United States Patent and Trademark Office. (2014). U.S. Patent No. 8,735,380, pharmaceutical composition comprising ulipristal acetate.
U.S. Food and Drug Administration. (2010). NDA 022474: ella (ulipristal acetate) tablets.
U.S. Food and Drug Administration. (2023). ella (ulipristal acetate) prescribing information.
U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations, commonly known as the Orange Book.

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Patented / Exclusive Use	Submissiondate
Lab Hra Pharma	ELLA	ulipristal acetate	TABLET;ORAL	022474-001	Aug 13, 2010	AB	RX	Yes	Yes	8,735,380	⤷ 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

PCT Information
PCT Filed	December 08, 2009	PCT Application Number:	PCT/EP2009/066652
PCT Publication Date:	June 17, 2010	PCT Publication Number:	WO2010/066749

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Australia	2009326084	⤷ Start Trial
Brazil	PI0922796	⤷ Start Trial
Canada	2745084	⤷ Start Trial
China	102245173	⤷ Start Trial
China	105267168	⤷ Start Trial
>Country	>Patent Number	>Estimated Expiration	>Supplementary Protection Certificate	>SPC Country	>SPC Expiration

Details for Patent: 8,735,380

Which drugs does patent 8,735,380 protect, and when does it expire?

Summary for Patent: 8,735,380