List of Excipients in Branded Drug LILETTA

Company	Tradename	Ingredient	NDC	Excipient	Potential Generic Entry
Allergan Inc	LILETTA	levonorgestrel	0023-5858	BARIUM SULFATE
Allergan Inc	LILETTA	levonorgestrel	0023-5858	DIMETHICONE

LILETTA Excipient Strategy, Patent Position, and Commercial Opportunities

Last updated: September 24, 2026

LILETTA is a levonorgestrel-releasing intrauterine system combining a 52-mg hormone reservoir with a polyethylene intrauterine device and silicone-based controlled-release components. Its commercial value depends less on conventional excipient substitution than on maintaining drug release, mechanical integrity, biocompatibility, sterility, and insertion performance over an extended product life. The highest-value opportunities are controlled-release silicone materials, qualified device manufacturing, generic or follow-on intrauterine systems, supply-chain localization, and lifecycle expansion in contraception and heavy menstrual bleeding.

What is LILETTA and how does its formulation work?

LILETTA is a drug-device combination product containing 52 mg of levonorgestrel. The device releases levonorgestrel directly into the uterine cavity at an initial rate of approximately 20 micrograms per day. The release rate declines over time as the drug reservoir is depleted. The FDA-approved duration is up to eight years for contraception and up to five years for treatment of heavy menstrual bleeding in patients who have chosen intrauterine contraception.[1]

What are LILETTA’s active and inactive materials?

The principal formulation and device materials are:

Component	Function
Levonorgestrel	Active pharmaceutical ingredient
Silicone elastomer	Drug reservoir and controlled-release matrix
Polydimethylsiloxane-related silicone material	Structural and release-control component
Colloidal silicon dioxide	Silicone elastomer reinforcing material
Polyethylene	T-shaped device frame
Barium sulfate	Radiopacity for visualization by imaging
Polyester or similar retrieval string	Device removal

The product is not a conventional tablet, capsule, or injectable formulation. Its relevant “excipient strategy” includes the drug-polymer matrix, rate-controlling membrane, device geometry, radiopaque additives, retrieval system, packaging, sterilization method, and assembly process.

The FDA label identifies the active ingredient and device materials, while detailed manufacturing specifications, polymer grades, coating parameters, particle-size requirements, and process controls are generally proprietary.[1]

What excipients control LILETTA’s drug release?

The silicone drug reservoir is the central release-control platform. Levonorgestrel is dispersed in a silicone elastomer, and the reservoir is designed to produce prolonged diffusion into the uterine environment.

Why silicone elastomer is commercially important

Silicone selection affects:

• Levonorgestrel solubility and dispersion
• Initial burst release
• Long-term release-rate decline
• Mechanical strength
• Flexibility during insertion
• Extractables and leachables
• Sterilization stability
• Shelf life
• Adhesion between the drug core and outer membrane

Small changes in silicone viscosity, curing chemistry, crosslink density, silica loading, or membrane thickness can alter the release profile. A substitute material therefore cannot be evaluated solely as a pharmaceutical excipient. It must be qualified as part of a drug-device system.

What is the role of colloidal silicon dioxide?

Colloidal silicon dioxide reinforces silicone elastomer and can affect processing viscosity, tensile strength, dimensional stability, and drug distribution. Its commercial value is tied to consistent surface chemistry, moisture control, particle-size distribution, and compatibility with the silicone curing system.

A new silica grade could create a meaningful change in drug release or mechanical properties. The supplier would need to demonstrate equivalence across formulation, molding, curing, sterilization, stability, and in vitro release testing.

What is the role of barium sulfate?

Barium sulfate makes the polyethylene frame radiopaque. It allows clinicians to identify the device by radiographic imaging and supports assessment of device position when clinically indicated.

Barium sulfate concentration and dispersion can influence:

• Radiographic visibility
• Polymer strength
• Flexibility
• Density
• Moldability
• Surface quality
• Long-term particulate stability

This is a device-material opportunity rather than a conventional excipient opportunity. Barium sulfate suppliers with validated medical-grade polymer dispersion capability may compete for supply, but qualification would require device-level testing.

What formulation and device patents protect LILETTA?

LILETTA protection is likely distributed across the product architecture rather than a single composition patent. Relevant patent categories include:

1. Levonorgestrel-loaded silicone reservoirs.
2. Intrauterine device geometry.
3. Drug-release membranes and diffusion pathways.
4. Reservoir loading and curing methods.
5. Insertion and deployment systems.
6. Retrieval-string attachment.
7. Radiopaque polymer components.
8. Treatment methods using a levonorgestrel intrauterine system.
9. Manufacturing controls for sustained release.

The product was developed by Medicines360 and commercialized in the United States through a relationship with AbbVie. FDA approval does not itself establish the full scope or remaining term of the patent estate. Patent numbers, listed claims, pediatric extensions, terminal disclaimers, and Orange Book status must be assessed from current USPTO and FDA records rather than inferred from the label.

What is the Orange Book status of LILETTA?

LILETTA is associated with FDA NDA 203159. Because it is a combination of a drug and a device, regulatory and intellectual-property analysis differs from a conventional oral small-molecule product. The relevant commercial barriers may include:

• Orange Book-listed patents, if any are currently listed
• Device or formulation patents not listed in the Orange Book
• Manufacturing know-how
• Product-specific release testing
• Sterility and packaging validation
• Device-design differences that complicate therapeutic-equivalence findings

Orange Book listing is not a complete measure of LILETTA’s competitive protection. A competitor may face non-Orange Book patent claims covering the device, manufacturing process, or use of the system.

When does LILETTA lose exclusivity?

LILETTA’s regulatory exclusivity and patent exclusivity are separate concepts.

Protection type	Relevant issue
New chemical entity exclusivity	Levonorgestrel was approved decades before LILETTA, so LILETTA does not receive new-molecule exclusivity based on levonorgestrel
New dosage form or delivery system	The intrauterine delivery system may qualify for product-specific regulatory exclusivity depending on the approval basis
Orphan exclusivity	Not applicable to contraception or ordinary heavy menstrual bleeding
Pediatric exclusivity	Applies only if granted for qualifying FDA-required pediatric studies
Patent protection	Depends on issued claims, listing status, terminal disclaimers, and expiration dates
Device and manufacturing protection	May continue through non-listed patents, trade secrets, supplier controls, and regulatory barriers

The commercial loss-of-exclusivity date cannot be determined from the product label alone. The likely entry date for a competing product depends on patent challenges, FDA review, product-specific equivalence standards, and litigation outcomes.

What generic entry risks exist for LILETTA?

Generic entry risk is real but structurally more difficult than for an oral levonorgestrel product. A competing manufacturer would need to reproduce or match critical performance characteristics while satisfying FDA requirements for a drug-device combination.

What would a LILETTA generic need to demonstrate?

A prospective ANDA or other abbreviated applicant would likely need evidence addressing:

• Same active ingredient and nominal drug content
• Comparable intrauterine delivery
• Comparable release-rate profile
• Comparable device dimensions and deployment
• Comparable insertion force
• Comparable retrieval performance
• Biocompatibility
• Sterility assurance
• Packaging integrity
• Extractables and leachables
• Stability throughout the labeled shelf life

The most difficult technical issue is likely in vitro and in vivo release comparability. A device with the same nominal 52-mg levonorgestrel content could still produce a materially different exposure profile if the silicone matrix, membrane, curing process, or geometry differs.

What are the most credible generic launch scenarios?

Scenario	Commercial effect
Directly equivalent intrauterine system	Highest substitution potential, but technically and legally demanding
Different levonorgestrel IUS with comparable duration	Competes for clinicians and patients without being a direct generic substitute
Lower-cost public-sector product	Could pressure pricing in Medicaid, family-planning, and institutional channels
Regional follow-on device	May compete outside the United States under local device and medicine rules
New-generation non-hormonal IUD	Competes through differentiation rather than direct equivalence

Which companies are challenging LILETTA?

No biosimilar pathway applies to LILETTA. Levonorgestrel is a synthetic small molecule, and LILETTA is a drug-device combination product rather than a biologic.

Competitive pressure is more likely to come from:

• Manufacturers developing follow-on levonorgestrel intrauterine systems
• Established IUD manufacturers
• Generic pharmaceutical companies with medical-device capabilities
• Contract manufacturers with silicone drug-delivery expertise
• Companies developing non-hormonal or lower-dose intrauterine products

Bayer’s Mirena and Kyleena remain the closest branded competitors in the U.S. hormonal intrauterine market. Paragard provides a non-hormonal alternative. LILETTA competes through its long duration, contraceptive efficacy, heavy menstrual bleeding indication, and access-oriented commercial model.

How does LILETTA compare with Mirena and Kyleena?

Attribute	LILETTA	Mirena	Kyleena
Active ingredient	Levonorgestrel	Levonorgestrel	Levonorgestrel
Nominal LNG content	52 mg	52 mg	19.5 mg
Contraceptive duration	Up to 8 years	Up to 8 years	Up to 5 years
Heavy menstrual bleeding indication	Up to 5 years	Up to 5 years	Not the principal U.S. indication
Product type	Hormonal IUS	Hormonal IUS	Hormonal IUS
Principal differentiation	Access, duration, HMB use	Established brand and broad clinical adoption	Lower hormone content and smaller device profile

Mirena has the strongest direct commercial overlap because it also contains 52 mg of levonorgestrel and carries a heavy menstrual bleeding indication. LILETTA’s commercial positioning has emphasized affordability and access, including availability through public-sector and family-planning channels.[2]

What commercial opportunities exist in LILETTA excipients?

1. Medical-grade silicone supply

Suppliers can compete on:

• Consistent low-extractables silicone
• Drug-dispersion uniformity
• Controlled viscosity
• Lot-to-lot cure performance
• Long-term biocompatibility
• Supply security

A qualified second source could have strategic value even without changing the formulation.

2. Controlled-release membrane technology

Membrane thickness, permeability, and surface treatment can create opportunities for:

• Faster qualification of alternative suppliers
• Improved release uniformity
• Reduced initial burst
• More predictable late-life dosing
• New-duration products using similar platform technology

Any change would require product-specific comparability and regulatory validation.

3. Radiopaque polymer systems

Barium sulfate masterbatches and medical-grade polyethylene compounds can support:

• Domestic or regional manufacturing
• Lower-cost device production
• Improved radiographic visibility
• Reduced variability in molding
• Alternative sterilization-compatible polymer systems

4. Contract manufacturing

The strongest commercial opportunity may be integrated manufacturing rather than standalone excipient sales. Qualified suppliers could provide:

• Silicone compounding
• Reservoir molding
• Drug loading
• Membrane application
• Device-frame molding
• Assembly
• String attachment
• Sterilization
• Packaging

Manufacturing know-how can create barriers that are difficult to replicate through public patent information.

5. Lifecycle management

The same platform may support:

• Lower-dose levonorgestrel systems
• Smaller insertion devices
• Longer-duration products
• New heavy menstrual bleeding claims
• Postpartum or adolescent positioning
• Regional products tailored to public-health procurement
• Combination programs with digital adherence or follow-up tools

What patent litigation and settlement risks affect LILETTA?

A Paragraph IV challenge could target listed patents covering the reservoir, device, method of use, or manufacturing process. The principal litigation questions would include:

• Whether a patent is properly listed
• Whether the asserted claims cover the proposed device
• Whether the challenger’s release profile is materially different
• Whether a manufacturing-process claim reaches the competitor
• Whether the patent is valid and enforceable
• Whether settlement terms delay launch or permit an authorized alternative

Settlement agreements in this area could include a licensed launch date, supply arrangements, royalty terms, or restrictions tied to product design. Public enforcement agencies may review patent settlements for anticompetitive provisions.

What FDA regulatory status applies to LILETTA?

LILETTA was approved by FDA in 2015 and is regulated as a prescription drug delivered through an intrauterine device. Its approval and labeling reflect both pharmaceutical and device controls.[1] The product’s active ingredient is not novel, so regulatory value rests on the delivery system, indication, duration, safety profile, manufacturing controls, and clinical evidence.

The heavy menstrual bleeding indication expands the addressable market beyond contraception and creates a second commercial use for the same platform.

How large is LILETTA’s revenue exposure?

AbbVie and Medicines360 do not consistently report LILETTA revenue as a separately identifiable public line item in the major corporate disclosures commonly used by investors. Product-level revenue exposure is therefore difficult to isolate from public filings.

The most relevant commercial segments are:

• U.S. contraception
• Heavy menstrual bleeding treatment
• Medicaid and public-sector procurement
• Family-planning clinics
• Hospital systems
• International markets, subject to local approvals
• Long-acting reversible contraception programs

Revenue sensitivity will depend on price, payer coverage, device availability, procedure reimbursement, and physician preference. The product’s low-frequency dosing and long duration can support favorable health-economic arguments, but upfront acquisition cost remains important in public tenders.

What is the geographic opportunity for LILETTA-related excipients?

The United States is the principal reference market because of FDA approval and the product’s established commercial position. Additional opportunities depend on local registration and procurement requirements in Europe, Canada, Latin America, Asia, and other markets.

Geographic expansion can create demand for:

• Locally qualified silicone and polymer suppliers
• Regional assembly sites
• Country-specific packaging
• Sterilization capacity
• Public-sector tender supply
• Regulatory documentation for medical-device materials

Excipient and device-material suppliers with global quality systems have an advantage because changing a critical material after approval can trigger significant regulatory work in multiple jurisdictions.

Key Takeaways

• LILETTA is a 52-mg levonorgestrel drug-device combination product with contraception approval for up to eight years.
• Its core excipient platform is a silicone-based controlled-release reservoir supported by silica-containing elastomer technology.
• Polyethylene and barium sulfate are critical device materials, not incidental components.
• The main technical barrier to generic entry is reproducing the drug-release and device-performance profile.
• LILETTA has no biosimilar risk because it is not a biologic.
• The closest branded comparator is Mirena, while Kyleena competes through lower hormone content and a smaller product profile.
• The strongest commercial opportunities are qualified silicone supply, radiopaque polymer systems, contract manufacturing, and follow-on intrauterine platforms.
• Public financial disclosures generally do not isolate LILETTA revenue, limiting precise revenue-exposure analysis.
• Patent risk must be assessed through current FDA Orange Book, USPTO, litigation, and settlement records. The label alone does not establish the complete patent estate.

FAQs

Can a supplier replace LILETTA’s silicone elastomer without a new approval?

A critical-material change would generally require documented comparability, process validation, stability data, biocompatibility assessment, and FDA review under the applicable post-approval change framework.

Is LILETTA protected by a composition-of-matter patent on levonorgestrel?

Levonorgestrel is an old active ingredient. Any meaningful protection is more likely to concern the intrauterine delivery system, formulation, device structure, method of use, or manufacturing process.

Could an oral levonorgestrel generic replace LILETTA?

No. An oral levonorgestrel product would not be therapeutically or regulatorily interchangeable with a long-acting intrauterine system.

Does LILETTA’s eight-year duration apply to heavy menstrual bleeding?

No. The U.S. labeling distinguishes the indications. Contraceptive use is approved for up to eight years, while heavy menstrual bleeding treatment is approved for up to five years.[1]

What is the most defensible excipient investment around LILETTA?

The strongest opportunity is usually a qualified, supply-secure silicone or medical-grade polymer platform that improves manufacturing reliability without changing the product’s clinically established release profile.

References

1. U.S. Food and Drug Administration. (2023). LILETTA levonorgestrel-releasing intrauterine system: Prescribing information. https://www.accessdata.fda.gov/drugsatfda_docs/label/2023/203159s016lbl.pdf

2. Medicines360. (n.d.). LILETTA. https://www.medicines360.org/liletta

3. U.S. Food and Drug Administration. (n.d.). Approved drug products with therapeutic equivalence evaluations, Orange Book. https://www.accessdata.fda.gov/scripts/cder/ob/

4. AbbVie Inc. (2024). Annual report pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934. https://investors.abbvie.com/financial-information/annual-reports-and-proxy-statements

5. U.S. Food and Drug Administration. (2020). Drug-device combination products. https://www.fda.gov/combination-products/about-combination-products/about-combination-products