List of Excipients in Branded Drug RETISERT

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Company	Tradename	Ingredient	NDC	Excipient	Potential Generic Entry
Bausch & Lomb Incorporated	RETISERT	fluocinolone acetonide	24208-416	CELLULOSE, MICROCRYSTALLINE
Bausch & Lomb Incorporated	RETISERT	fluocinolone acetonide	24208-416	MAGNESIUM STEARATE
Bausch & Lomb Incorporated	RETISERT	fluocinolone acetonide	24208-416	POLYVINYL ALCOHOL
Pharma Packaging Solutions LLC dba Tjoapack LLC	RETISERT	fluocinolone acetonide	75929-141	CELLULOSE, MICROCRYSTALLINE
Pharma Packaging Solutions LLC dba Tjoapack LLC	RETISERT	fluocinolone acetonide	75929-141	MAGNESIUM STEARATE
Pharma Packaging Solutions LLC dba Tjoapack LLC	RETISERT	fluocinolone acetonide	75929-141	POLYVINYL ALCOHOL

RETISERT Excipient Strategy, Patent Position, and Commercial Opportunities

Last updated: August 23, 2026

RETISERT is a surgically implanted fluocinolone acetonide delivery system for chronic noninfectious posterior uveitis. Its commercial value comes from controlled intravitreal release, not from a conventional tablet or injectable excipient package. The core formulation uses fluocinolone acetonide with polyvinyl alcohol, while silicone elastomer components control drug diffusion and physically contain the implant. The main opportunities are complex generic development, lower-dose implants, alternative release polymers, manufacturing supply, and product extensions that improve implantation, safety, or duration.

What is RETISERT and how does its formulation work?

RETISERT is an intravitreal implant containing 0.59 mg of fluocinolone acetonide. The FDA approved the product in 2005 for the treatment of chronic noninfectious posterior uveitis affecting the posterior segment of the eye.[1]

The implant is designed to release fluocinolone acetonide over approximately 30 months. It is surgically placed in the vitreous cavity. Unlike an injectable suspension, RETISERT provides a fixed drug reservoir and a rate-controlling release pathway.

Attribute	RETISERT
Active ingredient	Fluocinolone acetonide
Drug load	0.59 mg
Dosage form	Intravitreal implant
Administration	Surgical implantation
FDA application	NDA 021737
Original approval	2005
Release duration	Approximately 30 months
Primary indication	Chronic noninfectious posterior uveitis
Manufacturer/marketer	Bausch & Lomb-associated product portfolio
Product class	Corticosteroid drug-device combination

The clinical trade-off is clear: prolonged steroid exposure can reduce recurrence and treatment burden, but it increases the risk of cataract formation, intraocular pressure elevation, glaucoma and, in some patients, the need for additional surgery.[1]

What excipients and device materials are used in RETISERT?

RETISERT does not use a conventional liquid injectable formulation with a broad excipient system. The drug core contains fluocinolone acetonide and polyvinyl alcohol. The core is enclosed in a silicone elastomer cup and capped with a silicone elastomer release-rate-controlling orifice.[1]

RETISERT excipient and material architecture

Component	Functional role	Commercial relevance
Fluocinolone acetonide	Corticosteroid active ingredient	Controls potency, stability and dose loading
Polyvinyl alcohol	Drug-core matrix or binder	Supports physical integrity and drug release
Silicone elastomer cup	Encases the drug core	Provides biocompatibility and mechanical containment
Silicone elastomer cap/orifice	Controls diffusion and release rate	Creates a differentiated drug-delivery profile
Implant geometry	Determines surface area and diffusion path	Important for bioequivalence and manufacturing control

The silicone elastomer components are better characterized as device materials than as conventional pharmaceutical excipients. This distinction affects regulatory strategy, supplier qualification, extractables and leachables testing, sterilization validation, and combination-product manufacturing.

RETISERT’s excipient strategy is therefore a release-engineering strategy. The key variables are:

1. Drug-polymer compatibility.
2. Drug loading uniformity.
3. Matrix porosity and density.
4. Orifice dimensions.
5. Silicone elastomer permeability.
6. Implant geometry.
7. Sterilization effects on polymer properties.
8. Long-term stability in the ocular environment.

What formulation patents protect RETISERT?

RETISERT protection has historically been based on the implant architecture, drug reservoir, polymeric containment, and controlled-release configuration rather than on a novel small-molecule active ingredient. Fluocinolone acetonide is an established corticosteroid with extensive prior pharmaceutical use.

The most commercially relevant intellectual-property categories are:

• Reservoir implants containing fluocinolone acetonide.
• Silicone elastomer drug-delivery structures.
• Rate-controlling openings and diffusion pathways.
• Implant geometry and surgical placement.
• Long-duration intraocular corticosteroid delivery.
• Manufacturing methods for drug-polymer cores and implant assemblies.

The original RETISERT patent estate was filed many years before the product’s 2005 approval. Core U.S. patent terms associated with early implant patents have largely reached or passed their ordinary 20-year terms, subject to patent-term adjustment and continuation-specific analysis. Patent status must be assessed claim by claim in the USPTO records and FDA Orange Book rather than inferred from the product’s approval date.[2,3]

A developer evaluating RETISERT should separate three issues:

IP issue	Strategic question
Core formulation	Can the proposed product avoid active claims covering fluocinolone acetonide in a polymeric implant?
Device structure	Does the implant replicate protected cup, cap, or orifice architecture?
Manufacturing process	Are fabrication, loading, sealing, sterilization, or assembly claims still enforceable?

A freedom-to-operate analysis should include expired patents because they can still reveal claim scope, technical design history, and continuation-family members. Current enforceability depends on the specific patent, jurisdiction, maintenance history and claim language.

When does RETISERT lose exclusivity?

RETISERT’s regulatory exclusivity is separate from its patent protection.

The product was approved in 2005 under NDA 021737. Its five-year new chemical entity exclusivity would have expired in 2010, assuming the FDA classified the application as eligible for that period. The product’s three-year clinical-investigation exclusivity is not the primary barrier for a product approved with an established active ingredient and a novel delivery system.[1,4]

The commercial barriers are more likely to arise from the complexity of the drug-device product than from remaining regulatory exclusivity.

Exclusivity or barrier	RETISERT implication
New chemical entity exclusivity	Expired
Three-year exclusivity	Not the principal current barrier
Core early patent terms	Generally mature or expired, subject to family-specific review
Device and manufacturing know-how	May remain commercially significant
Clinical and performance evidence	Important for an ANDA or 505(b)(2) strategy
Supplier and process controls	Potential source of practical differentiation

The absence of an active, long-duration patent barrier does not make development straightforward. Intravitreal implants require reproducible release performance, sterile manufacturing, biocompatibility evidence, and a credible demonstration that the proposed product has equivalent clinical behavior.

What is the Orange Book status of RETISERT?

RETISERT is listed in FDA Drugs@FDA under NDA 021737. Orange Book analysis should focus on whether current patents remain listed, whether any listed patents have expired, and whether the FDA has accepted any abbreviated applications referencing the product.[2,3]

For a complex implant, Orange Book information is only one part of the competitive analysis. A product can face significant development risk even when no enforceable Orange Book patent blocks launch. The principal technical questions include:

• Whether the product can match the reference implant’s release profile.
• Whether the implant has the same active ingredient and dosage form.
• Whether the proposed implant uses the same route and site of administration.
• Whether differences in polymer, orifice, dimensions, or surgical technique require a 505(b)(2) application.
• Whether the FDA would require comparative clinical data.

Which companies are challenging RETISERT or competing with it?

No biosimilar pathway applies to RETISERT because fluocinolone acetonide is a small-molecule corticosteroid and RETISERT is not a biologic. The competitive threat is therefore from generic or follow-on drug-device products, not biosimilars.

Direct and adjacent competitors

Product	Active ingredient	Delivery system	Approximate duration	Competitive position
RETISERT	Fluocinolone acetonide, 0.59 mg	Surgically implanted reservoir	Approximately 30 months	Long-duration uveitis implant
YUTIQ	Fluocinolone acetonide, 0.18 mg	Injectable intravitreal implant	Up to approximately 36 months	Lower-dose, office-based alternative
ILUVIEN	Fluocinolone acetonide, 0.19 mg	Injectable intravitreal implant	Up to approximately 36 months	Chronic diabetic macular edema and other approved uses depending on market
OZURDEX	Dexamethasone	Biodegradable intravitreal implant	Up to approximately six months	Shorter-duration steroid implant
Injectable corticosteroid therapies	Various	Intravitreal injection	Weeks to months	Lower procedural barrier but greater treatment frequency

YUTIQ and ILUVIEN create the most relevant commercial comparison because they use the same active corticosteroid but different dose levels, delivery structures and implantation methods.[5,6] Their office-based administration can reduce the procedural burden associated with surgically implanted RETISERT.

What commercial opportunities exist for RETISERT excipients?

Can a generic manufacturer develop a RETISERT equivalent?

Yes, but the product should be treated as a complex drug-device development program. A conventional oral-product generic strategy is unlikely to capture the full technical burden.

Potential regulatory pathways include:

• An ANDA if the FDA accepts the product as pharmaceutically and therapeutically equivalent to RETISERT.
• A 505(b)(2) application if the product differs in polymer, implant structure, dose, release profile, or clinical use.
• A combination-product pathway involving both drug and device evaluation.

The highest-value development targets are:

1. A functionally equivalent fluocinolone acetonide implant.
2. A lower-dose version with reduced steroid-related adverse events.
3. A longer-duration implant that reduces replacement procedures.
4. A smaller implant that simplifies surgical placement.
5. An implant with more predictable release near the end of its life.
6. A version with improved radiographic or surgical visibility.
7. A product compatible with less invasive implantation techniques.

What excipient substitutions could create differentiation?

Polyvinyl alcohol is central to the drug-core design, but alternative matrix systems could create new intellectual property and performance profiles. Candidate approaches include biodegradable polymers, nonbiodegradable hydrophilic matrices, silicone-polymer composites and drug-loaded microporous structures.

A substitution strategy must preserve:

• Fluocinolone chemical stability.
• Uniform drug distribution.
• Controlled diffusion.
• Sterility after manufacturing.
• Ocular biocompatibility.
• Mechanical integrity during implantation.
• Predictable end-of-life release.

Changing the polymer can alter the regulatory classification and require new toxicology, release, extractables and leachables, and clinical evidence. The commercial benefit must therefore exceed the cost of establishing equivalence or clinical safety.

What manufacturing and IP barriers affect RETISERT follow-on products?

The major barriers are process-related.

Manufacturing barriers

RETISERT-type manufacturing may require:

• Precise drug-polymer mixing.
• Controlled formation of the drug core.
• Reproducible core dimensions.
• Silicone cup and cap molding.
• Micron-scale control of the release orifice.
• Hermetic or near-hermetic assembly.
• Sterilization without altering polymer permeability.
• Long-term in vitro release testing.
• Low-particulate sterile packaging.

The release rate is sensitive to geometry and material properties. Small changes in orifice size, silicone thickness, core density or polymer composition can create clinically relevant changes in exposure.

Intellectual-property barriers

A follow-on developer must evaluate:

• Implant architecture claims.
• Drug-polymer composition claims.
• Release-rate claims.
• Surgical implantation claims.
• Manufacturing and assembly claims.
• Continuation and divisional patent families.
• Foreign patent rights in Europe, Japan, Canada and other commercial markets.

European and other non-U.S. markets may have different patent expiry dates, supplementary protection certificate considerations, regulatory exclusivity rules and combination-product requirements. A U.S. patent clearance does not establish global freedom to operate.

What generic launch risks exist for RETISERT?

A generic launch would face five principal risks:

Risk	Impact
Demonstrating comparable release	May require extensive in vitro and possibly clinical evidence
Device equivalence	Structural differences can trigger 505(b)(2) requirements
Surgical administration	Label and training differences may limit substitution
Sterile manufacturing	Raises capital and quality-system requirements
Small market size	May not support investment without premium pricing or licensing

The commercial opportunity is strongest for a company that already manufactures sterile ophthalmic implants, silicone drug-delivery devices or complex combination products. A conventional generic-drug manufacturer would face a steeper entry curve.

What licensing deals could support a RETISERT follow-on?

Licensing opportunities may arise around:

• Fluocinolone acetonide implant technology.
• Silicone elastomer drug-delivery platforms.
• Biodegradable intraocular polymers.
• Microfabricated release orifices.
• Sterile implant assembly.
• Regional commercialization rights.
• Manufacturing technology transfer.

A practical transaction structure could combine an ophthalmic drug-device platform owner with a generic manufacturer that has ANDA or 505(b)(2) capabilities. The asset value would depend on demonstrated release equivalence, patent clearance, manufacturing readiness and access to ophthalmology sales channels.

Public disclosures do not establish a material RETISERT-specific licensing transaction that defines the current commercial market. Product-level revenue is also not consistently reported separately by the sponsor, so RETISERT revenue exposure cannot be quantified reliably from public company filings alone.

How strong is the RETISERT patent estate?

The original patent position was commercially meaningful because it protected a long-duration intraocular corticosteroid delivery system. Its current strength is more limited where core patents have expired or approached expiry. The remaining strategic value is likely concentrated in:

• Unexpired continuation claims, if any.
• Manufacturing know-how.
• Device tolerances and quality controls.
• Regulatory data and development history.
• Supplier relationships.
• Clinical familiarity among retinal and uveitis specialists.

The patent estate should therefore be rated as technically influential but potentially less effective as a standalone current market barrier. Manufacturing capability and regulatory execution may be more important than basic composition-of-matter protection.

Key Takeaways

• RETISERT contains 0.59 mg of fluocinolone acetonide in a long-duration intravitreal implant.
• The drug core uses polyvinyl alcohol, while silicone elastomer components contain the drug and control release.
• The product is a complex drug-device system, not a conventional excipient-based injectable.
• Its five-year regulatory exclusivity period has expired.
• No biosimilar pathway applies; competitive entry would come from generics or 505(b)(2) follow-on implants.
• YUTIQ and ILUVIEN are the closest commercial comparators because they use lower-dose fluocinolone acetonide implants.
• The best commercial opportunities involve equivalent implants, lower-dose products, longer-duration systems, improved implantation and specialized manufacturing.
• The principal barriers are release-rate equivalence, sterile implant manufacturing, device characterization and clinical evidence.
• Early RETISERT patent protection is mature, making process know-how and regulatory execution increasingly important.
• Public filings do not provide a reliable standalone RETISERT revenue figure.

FAQs

Is polyvinyl alcohol the main pharmaceutical excipient in RETISERT?

Polyvinyl alcohol is used in the fluocinolone acetonide drug core. The silicone elastomer cup, cap and release orifice are functional implant materials that control containment and diffusion.

Can RETISERT be substituted with YUTIQ?

The products are not automatically interchangeable. They contain different drug loads and use different implant systems and administration methods. Substitution depends on the applicable label, clinical judgment and regulatory requirements.

Does RETISERT have biosimilar competition?

No. Fluocinolone acetonide is a small-molecule corticosteroid. Potential follow-on products would use generic or 505(b)(2) pathways rather than the biosimilar pathway.

What is the most valuable RETISERT formulation innovation?

A lower-dose implant that maintains durable efficacy while reducing cataract and intraocular-pressure complications would have the strongest potential clinical and commercial differentiation.

Why is a RETISERT generic harder to develop than a tablet generic?

The developer must reproduce drug release, implant dimensions, polymer behavior, sterility, mechanical integrity and ocular performance. These requirements create a drug-device equivalence problem in addition to active-ingredient sameness.

References

1. U.S. Food and Drug Administration. (2005). RETISERT (fluocinolone acetonide intravitreal implant) prescribing information.
2. U.S. Food and Drug Administration. (n.d.). Drugs@FDA: RETISERT, NDA 021737.
3. U.S. Food and Drug Administration. (n.d.). Approved drug products with therapeutic equivalence evaluations, Orange Book.
4. U.S. Food and Drug Administration. (2017). Guidance for industry: Applications covered by section 505(b)(2).
5. U.S. Food and Drug Administration. (2018). YUTIQ (fluocinolone acetonide intravitreal implant) prescribing information.
6. U.S. Food and Drug Administration. (2014). ILUVIEN (fluocinolone acetonide intravitreal implant) prescribing information.