Details for Patent: 10,849,884

Which drugs does patent 10,849,884 protect, and when does it expire?

Patent 10,849,884 protects SOLOSEC and is included in one NDA.

This patent has sixteen patent family members in five countries.

Summary for Patent: 10,849,884

Title:	Secnidazole for use in the treatment of bacterial vaginosis
Abstract:	Embodiments are directed to a secnidazole formulations and the use of a secnidazole formulation for the treatment of bacterial vaginosis (BV).
Inventor(s):	Helen S. PENTIKIS, David Palling, Carol J. BRAUN
Assignee:	Evofem Biosciences Inc
Application Number:	US16/403,176
Patent Claim Types: see list of patent claims	Use; Composition; Formulation; Dosage form;

United States Patent 10,849,884: Secnidazole Microgranules, Contraceptive Compatibility, and Bacterial Vaginosis Treatment

US 10,849,884 protects a narrow 2-gram, single-dose oral secnidazole product defined by its microgranule architecture, particle-size distribution, and pharmacokinetic profile. The patent also claims co-administration with ethinyl estradiol and norethindrone, administration with food vehicles, use in recurrent or pregnant patients, and reduction of sexually transmitted infection risk.

The core commercial relevance is to Solosec, the branded secnidazole oral granule product marketed in the United States by Lupin Pharmaceuticals following Lupin’s acquisition of Symbiomix Therapeutics. The strongest composition claims require all of the following: secnidazole as the sole drug, sugar-sphere-based microgranules, povidone, an ethyl acrylate-methyl methacrylate copolymer, 400 to 841 micrometer particles, a 2-gram dose, and a specified Cmax range within a defined post-dose period.

What does US Patent 10,849,884 protect?

US 10,849,884 protects a pharmaceutical composition and related treatment methods centered on a 2-gram single oral dose of secnidazole.

Protected feature	Requirement in claims 1 and 2
Active ingredient	Secnidazole
Dose	2 grams
Drug composition	Secnidazole is the sole drug
Dosage form	Plurality of microgranules
Core	Sugar sphere
Binder or excipient	Povidone
Coating polymer	Ethyl acrylate-methyl methacrylate copolymer
Particle size	400 to 841 micrometers
Administration	Oral
Pharmacokinetics	Cmax of 34.5 to 58.3 micrograms/mL
Timing for Cmax	Two to six hours for claim 1; three to four hours for claim 2

The patent does not broadly cover every secnidazole formulation or every 2-gram oral secnidazole product. It requires a defined multiparticulate formulation and a pharmacokinetic result.

The claims are composition claims, method-of-treatment claims, and a prevention-oriented method claim. They do not claim secnidazole as a chemical compound.

How many independent claims does US 10,849,884 have?

The patent has five independent claim categories:

1. Claim 1: The defined single-dose secnidazole microgranule composition with a Cmax measured two to six hours after administration.
2. Claim 2: The same composition with a narrower three-to-four-hour Cmax timing window.
3. Claim 3: Treatment of bacterial vaginosis with the claim 1 composition co-administered with ethinyl estradiol, norethindrone, or both on the same day.
4. Claim 23: Oral administration of the claim 1 composition to reduce the risk of acquiring a specified sexually transmitted infection.
5. Claims 14 and 15, although method claims dependent on claims 1 and 2, create separate protection for co-administration on a different day.

Claims 4 through 6, 16, and 17 extend the contraceptive co-administration concepts. Claims 7 through 13 and 18 through 22 add formulation, food, patient-population, and recurrence limitations.

What is the scope of claims 1 and 2?

Claims 1 and 2 are the principal product claims. Their scope is cumulative. A potentially infringing product would need to satisfy every material limitation, not merely contain 2 grams of secnidazole.

Microgranule structure

Each microgranule must comprise:

• Secnidazole;
• A sugar sphere;
• Povidone; and
• An ethyl acrylate-methyl methacrylate copolymer.

This language points to a layered or coated multiparticulate system rather than a conventional tablet, powder, capsule fill, or unstructured granule. The sugar sphere is a structural limitation. A formulation using a different inert core, such as a starch sphere, cellulose sphere, or directly granulated secnidazole particle, presents a potential literal non-infringement position.

The polymer limitation is also material. Ethyl acrylate-methyl methacrylate copolymer is commonly used as a modified-release or protective coating polymer. A formulation using a different acrylic polymer, a cellulose-based coating, or no polymer coating could avoid literal satisfaction of this element, subject to an equivalents analysis.

Particle diameter

The claimed particle diameter is 400 to 841 micrometers. A formulation with particles entirely below 400 micrometers or above 841 micrometers would have a potential design-around position. Mixed populations require closer analysis. If a commercial product contains a substantial population within the claimed range, infringement may depend on how the claim term "each microgranule" is construed and how particle size is measured.

The lower and upper limits are technically significant. The range corresponds to a controlled multiparticulate size distribution that can affect coating uniformity, dissolution, dispersion in food, and gastrointestinal transit.

Pharmacokinetic limitation

Claims 1 and 2 require a Cmax between 34.5 and 58.3 micrograms/mL. The claims also specify when the Cmax is observed:

• Claim 1: two to six hours after administration.
• Claim 2: three to four hours after administration.

These limitations create potential enforcement and validity issues. A product could have the same qualitative formulation but fall outside the claimed Cmax range. Conversely, a product with a different formulation could potentially satisfy the pharmacokinetic limitation if it produces the claimed exposure profile.

The claims do not state a particular analytical method, study population, food state, or sampling protocol in the claim text supplied. Those parameters would likely be important in any infringement dispute. Pharmacokinetic testing would need to address dose, fed or fasted state, subject characteristics, sampling intervals, assay methodology, and statistical treatment.

Claim 2 is narrower than claim 1 because its Cmax must be observed within the three-to-four-hour window. It may be easier to design around than claim 1, but it could be more difficult to invalidate based on an earlier or later pharmacokinetic profile.

What do the dependent formulation claims cover?

Polyethylene glycol and talc

Claims 7 and 18 require at least one of polyethylene glycol or talc in addition to the composition of claim 1 or claim 2. These claims provide narrower protection for specific excipient configurations.

They are unlikely to capture a formulation that lacks both polyethylene glycol and talc. Their practical value depends on whether the marketed formulation uses one of those excipients and whether the excipient is present in each microgranule or elsewhere in the dosage form.

Food-integrated administration

Claims 8 through 9 and 19 through 20 cover the composition when integrated with a food substance. The listed vehicles are:

• Applesauce;
• Yogurt; and
• Pudding.

These claims track the administration format associated with oral granules. They could be relevant where the product is supplied or instructed for administration by sprinkling or mixing the granules into a soft food.

The claims do not appear to cover every food vehicle under the express dependent claims. A different food vehicle may still implicate the broader parent composition claims if the remaining limitations are satisfied.

Patient populations

Claims 10 through 13 and 21 through 22 target:

• Female patients;
• Pregnant females; and
• Females with bacterial vaginosis occurring at least three or four times during the previous 12 months.

These limitations are method or use restrictions layered onto the composition claims. They have narrower enforcement reach because the relevant patient characteristics and treatment history must be established.

The recurrent-bacterial-vaginosis claims are commercially relevant to a population with repeated antibiotic exposure and a potentially higher need for single-dose treatment. The pregnancy limitation creates separate technical and regulatory importance because secnidazole labeling and pregnancy data would be central to any use analysis.

What do claims 3 through 6 and 14 through 17 protect?

These claims address the interaction between secnidazole and hormonal contraceptives.

Claims	Co-administered compound	Timing or effect limitation
3 and 4	EE2, NET, or both	Same day
5 and 16	EE2, NET, or both	Pharmaceutical composition containing the additional compound
6 and 17	EE2, NET, or both	Secnidazole does not affect contraceptive efficacy
14 and 15	EE2, NET, or both	Different day
16	EE2, NET, or both	Pharmaceutical composition
17	EE2, NET, or both	No effect on contraceptive efficacy

EE2 is ethinyl estradiol. NET is norethindrone.

The claims are directed to treatment of bacterial vaginosis while using a hormonal contraceptive regimen. Claims 3, 4, 14, and 15 distinguish same-day and different-day administration. Claims 6 and 17 add a pharmacodynamic or clinical-effect limitation stating that secnidazole does not affect contraceptive efficacy.

These claims are harder to enforce than the composition claims because infringement depends on the prescribed or actual treatment regimen. They may be relevant to labeling, prescribing instructions, clinical trial protocols, and promotional statements concerning contraceptive compatibility.

What does claim 23 cover for sexually transmitted infection prevention?

Claim 23 covers orally administering the claim 1 composition to reduce the risk of acquiring an STI from a sexual partner.

Claims 24 through 26 narrow the STI to:

• Chlamydia;
• Gonorrhea;
• Trichomoniasis;
• Herpes simplex virus 2;
• Human papillomavirus; and
• Trichomoniasis caused by Trichomonas vaginalis.

This is a broad method-of-use concept relative to the composition claims. The claim does not require that the subject have bacterial vaginosis. It requires use of the claimed secnidazole composition for risk reduction.

A critical distinction is that secnidazole is an antibacterial and antiprotozoal agent. The dependent claims list viral infections, including herpes simplex virus 2 and human papillomavirus. The scope of these claims would depend heavily on the patent specification’s support, clinical evidence, enablement, and the construction of "reducing a risk."

From a commercial perspective, the STI claims are less directly aligned with the principal FDA-approved bacterial-vaginosis indication than the composition and BV-treatment claims. Their regulatory and enforcement value would depend on whether the relevant use is approved, promoted, prescribed, or supported by clinical evidence.

When does US 10,849,884 lose exclusivity?

The patent issued on December 1, 2020. Its nominal expiration is expected to fall in 2037 based on the patent’s underlying filing and priority framework, subject to patent-term adjustment, terminal disclaimer issues, and any applicable statutory correction.

Milestone	Date or status
Patent	US 10,849,884 B2
Issue date	December 1, 2020
Nominal patent term	Generally 20 years from the applicable nonprovisional filing date
Expected term period	2037, subject to USPTO term calculation
Regulatory exclusivity	Separate from patent term
Generic pathway	ANDA with possible Paragraph IV certification

The operative expiration date should be taken from the USPTO Patent Center term information and any terminal disclaimer or patent-term-adjustment record. A patent’s issue date does not determine its expiration date.

For an ANDA applicant, the commercial launch date could occur before patent expiration if the applicant prevails in litigation, obtains a settlement license, or otherwise receives authorization to launch.

What is the Orange Book status of US 10,849,884?

Solosec is associated with FDA NDA 209363. The relevant regulatory patent analysis requires comparison of US 10,849,884 with the current FDA Orange Book patent listing for that NDA.

The Orange Book question has four parts:

1. Whether US 10,849,884 is listed for NDA 209363.
2. Whether the listing carries a method-of-use code, a drug-product code, or both.
3. Whether the listing remains active in the current Orange Book edition.
4. Whether the listed claims correspond to the approved 2-gram oral granule product and its approved use.

The patent’s product claims are more likely to support a drug-product listing than the STI-prevention claims, which may not correspond to the approved labeling. The contraceptive-interaction claims could support a use listing only if the relevant use is reflected in the approved labeling and FDA listing information.

Orange Book listing and patent validity are separate issues. Listing creates an ANDA certification obligation but does not establish that every listed claim is valid or infringed. The FDA Orange Book and the approved Solosec label are the controlling regulatory sources for current listing and exclusivity information.[1][2]

Which companies are challenging the secnidazole patent estate?

The principal potential challengers are generic manufacturers filing ANDAs for secnidazole oral granules or equivalent oral dosage forms. A Paragraph IV certification would allege that a listed patent is invalid, unenforceable, or not infringed.

The relevant competitive groups are:

Challenger type	Likely strategy
Generic oral-granule manufacturer	Challenge particle size, excipient structure, polymer identity, or pharmacokinetic limitations
Alternative dosage-form manufacturer	Use tablets, capsules, powders, or different granules
Formulation developer	Change the sugar sphere, binder, coating polymer, or particle-size distribution
Label-focused ANDA applicant	Seek a carve-out for protected methods of use
International manufacturer	Avoid US claims through a different manufacturing process or product architecture

A complete litigation assessment requires PACER, FDA Paragraph IV records, USPTO Patent Center, and district-court docket review. The supplied patent claims alone do not establish that a particular company has filed a challenge or that litigation is pending.

How strong is the patent estate for Solosec?

The patent is strongest against a copycat product that reproduces the branded formulation architecture and pharmacokinetic profile.

Strengths

• The composition claims contain multiple structural limitations.
• The claims combine formulation structure with particle size and Cmax.
• A direct copy of the marketed product may satisfy several independent limitations simultaneously.
• The same patent covers product use in conjunction with hormonal contraceptives.
• Food-administration claims correspond to a commercially practical administration method.

Vulnerabilities

• The claims are narrow and may be designed around.
• Particle size can potentially be shifted outside the claimed range.
• A different core or coating polymer may avoid literal infringement.
• Pharmacokinetic results can vary with food, patient population, sampling design, and formulation.
• Method claims depend on actual prescribing or administration behavior.
• STI-prevention claims may face written-description, enablement, utility, or regulatory-use challenges depending on the supporting disclosure and approved indication.
• Prior-art analysis may focus on earlier secnidazole granules, multiparticulate dosage forms, acrylic coating polymers, food-mixed oral granules, and pharmacokinetic disclosures.

The patent therefore provides targeted protection rather than a broad compound monopoly. Its commercial strength depends on whether the approved Solosec formulation falls squarely within the claims and whether generic applicants can obtain equivalent exposure with a different microgranule design.

How does US 10,849,884 compare with other secnidazole protection?

Protection category	US 10,849,884	Commercial significance
Secnidazole compound	No	Compound was known before this patent
2-gram oral dose	Yes, but with additional limitations	Protects a specific product configuration
Multiparticulate granules	Yes	Core product protection
Sugar-sphere formulation	Yes	Narrows composition scope
Acrylic copolymer coating	Yes	Potential design-around target
Cmax range	Yes	Adds pharmacokinetic limitation
Bacterial vaginosis treatment	Yes	Main approved-use alignment
Hormonal contraceptive co-administration	Yes	Compatibility and prescribing-use protection
Food administration	Yes	Supports commercial granule administration
STI-risk reduction	Yes	Broader but potentially more vulnerable use claims
Biosimilar protection	No	Secnidazole is a small-molecule drug

US 10,849,884 should be analyzed together with other secnidazole patents, FDA-listed patents, regulatory exclusivity, and any pending continuation or divisional applications. A single patent does not define the full Solosec exclusivity position.

What generic launch risks exist?

A generic launch can occur through several routes:

1. At-risk launch. The applicant launches before patent expiration after receiving FDA approval, accepting potential damages and injunction risk.
2. Paragraph IV litigation. The applicant challenges validity, enforceability, or infringement and obtains a favorable judgment or settlement.
3. Design-around formulation. The applicant uses a different particle-size range, core material, binder, coating polymer, or release profile.
4. Label carve-out. The applicant removes protected method-of-use information while retaining an unprotected bacterial-vaginosis indication, if FDA permits the carve-out.
5. Licensed entry. The applicant settles with the patent owner and receives a defined launch date.

The most credible technical design-around would target the combination of sugar sphere, povidone, ethyl acrylate-methyl methacrylate copolymer, and 400-to-841-micrometer particles. A separate strategy would target the Cmax limitation through altered release, particle size, food instructions, or excipient composition.

What manufacturing and geographic barriers does the patent create?

The patent’s manufacturing relevance lies in the required microgranule construction. A manufacturer must control:

• Sugar-sphere loading;
• Povidone distribution;
• Polymer coating composition;
• Granule size classification;
• Dose uniformity;
• Dissolution and release behavior;
• Cmax exposure; and
• Compatibility with applesauce, yogurt, or pudding administration.

A non-US manufacturer can avoid US infringement only if the product is not made, used, sold, offered for sale, or imported in a manner covered by US patent law. Exporting an infringing product for US importation can create liability under 35 U.S.C. § 271. Foreign patent rights must be analyzed separately. A US patent does not automatically block sale in Canada, Europe, Japan, or other markets.

Key Takeaways

• US 10,849,884 is a formulation and method-of-use patent, not a broad secnidazole compound patent.
• Claims 1 and 2 require a 2-gram single oral dose composed of defined secnidazole microgranules.
• The critical structural limitations are the sugar sphere, povidone, ethyl acrylate-methyl methacrylate copolymer, and 400-to-841-micrometer particle size.
• The Cmax range of 34.5 to 58.3 micrograms/mL materially narrows the composition claims.
• Claim 2 has a narrower three-to-four-hour pharmacokinetic window than claim 1.
• The patent covers bacterial-vaginosis treatment with hormonal contraceptive co-administration and no demonstrated loss of contraceptive efficacy.
• Food-mixed administration and recurrent or pregnancy-related patient populations are separately claimed.
• Claims 23 through 26 extend to reducing STI acquisition risk, including trichomoniasis.
• The principal generic design-around options are a different microgranule core, coating polymer, particle-size distribution, release profile, or dosing architecture.
• Patent expiration, Orange Book listing, Paragraph IV activity, and litigation status must be assessed against current USPTO, FDA, and court records.

FAQs About US Patent 10,849,884

Does US 10,849,884 cover all 2-gram secnidazole products?

No. The claims require specific microgranule ingredients, particle size, oral administration, sole-drug status, and pharmacokinetic results.

Can a generic use secnidazole in a tablet instead of microgranules?

A tablet may avoid the literal composition limitations if it does not contain the claimed microgranules. The analysis would still require review of any other applicable secnidazole patents and method claims.

Does the patent cover secnidazole combined with birth-control hormones in one product?

The claims cover co-administration with ethinyl estradiol and norethindrone. They do not necessarily require that the two drugs be physically combined in the same dosage unit.

Are the STI-prevention claims equivalent to an FDA-approved indication?

No. Patent claim scope and FDA-approved labeling are separate. A patent can contain a method claim broader than the approved indication.

Is a biosimilar challenge relevant to secnidazole?

No. Secnidazole is a small-molecule drug. The relevant abbreviated pathway is generally an ANDA, not a biosimilar application under the Biologics Price Competition and Innovation Act.

References

1. U.S. Food and Drug Administration. (n.d.). Orange Book: Approved drug products with therapeutic equivalence evaluations. https://www.accessdata.fda.gov/scripts/cder/ob/
2. U.S. Food and Drug Administration. (n.d.). Solosec prescribing information. NDA 209363.
3. U.S. Patent and Trademark Office. (2020). U.S. Patent No. 10,849,884 B2. Patent Center. https://patentcenter.uspto.gov/
4. U.S. Code. 35 U.S.C. §§ 154, 271, and 271(e).
5. U.S. Food and Drug Administration. (n.d.). Approved drug products with therapeutic equivalence evaluations and patent certification requirements.

Drugs Protected by US Patent 10,849,884

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Patented / Exclusive Use	Submissiondate
Evofem Inc	SOLOSEC	secnidazole	GRANULE;ORAL	209363-001	Sep 15, 2017		RX	Yes	Yes			Y			TREATMENT OF BACTERIAL VAGINOSIS IN FEMALE PATIENTS 12 YEARS OF AGE AND OLDER
Evofem Inc	SOLOSEC	secnidazole	GRANULE;ORAL	209363-001	Sep 15, 2017		RX	Yes	Yes			Y			TREATMENT OF TRICHOMONIASIS IN PATIENTS 12 YEARS OF AGE AND OLDER
Evofem Inc	SOLOSEC	secnidazole	GRANULE;ORAL	209363-001	Sep 15, 2017		RX	Yes	Yes			Y			TREATMENT OF TRICHOMONIASIS IN ADULTS
Evofem Inc	SOLOSEC	secnidazole	GRANULE;ORAL	209363-001	Sep 15, 2017		RX	Yes	Yes			Y			TREATMENT OF BACTERIAL VAGINOSIS IN ADULT WOMEN

International Family Members for US Patent 10,849,884

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Australia	2015311674
Australia	2018203882
Australia	2018217262
Canada	2959414
Canada	3046521