United States Patent 7,799,336: Scope, Claims, Expiration and Patent Landscape for Prostamide Intraocular Implants

US 7,799,336 covers biodegradable intraocular implants containing a prostamide, particularly bimatoprost, in a biodegradable polymer matrix that provides sustained ocular release. The broadest claim reaches an implant that releases a therapeutically effective prostamide dose for at least one week. Dependent claims narrow the estate to bimatoprost, polymer blends, vitreous placement, release exceeding one month, combination glaucoma therapy and extrusion manufacturing.

The patent is commercially relevant to biodegradable sustained-release glaucoma implants, including bimatoprost implant products. Its practical value depends on claim construction, patent-term status, Orange Book listing, continuation patents and whether a competing product uses a different drug, delivery location or non-biodegradable reservoir.

What does US Patent 7,799,336 protect?

The patent protects a product combination with four core elements:

An intraocular implant.
A prostamide component.
A biodegradable polymer matrix.
Sustained release of a therapeutically effective amount of the prostamide for at least approximately one week after ocular placement.

Independent claim 1 is compositionally broad. It does not require:

Bimatoprost specifically.
A particular implant size or shape.
A particular polymer ratio.
A specific ocular chamber.
A particular release profile beyond the one-week threshold.
A particular manufacturing process.
Treatment of glaucoma as the express indication.

The claim does require the implant to release drug at a therapeutically effective rate. A biodegradable implant containing a prostamide but releasing the drug too rapidly, too slowly or at a nontherapeutic level would face a claim-scope defense.

Claim architecture

Claim	Principal limitation	Commercial significance
1	Prostamide plus biodegradable polymer matrix; sustained release for at least about one week	Broadest product claim
2	Single type of prostamide derivative	Excludes a required mixture of different prostamide derivatives
3	Prostamide dispersed within the matrix	Relevant to matrix-based formulations
4	Bimatoprost at about 0.1% to about 90% by weight	Directly targets bimatoprost implants
5	Broad chemical Markush definition of prostamide compounds	Extends protection beyond named bimatoprost
6	Two different biodegradable polymers	Protects blended polymer matrices
7	Two different polylactic acids	Narrow polymer-blend claim
8	Polylactic acid plus polylactide-co-glycolide	Covers a common biodegradable polymer combination
9	Polymers with different inherent viscosities	Targets release control through polymer properties
10	Polymers with different molecular weights	Targets release control through polymer degradation and diffusion
11	Release for more than one month in the vitreous	Stronger duration limitation for long-acting products
12	Amount effective to stimulate aqueous humor outflow	Links the implant to a recognized glaucoma pharmacology
13-15	Prostaglandin analogue or other pressure-lowering drug	Combination therapy coverage
16	Structured for placement in the vitreous	Narrows the product to vitreous delivery
17	Formed by extrusion	Manufacturing-process limitation

How broad is claim 1 of US 7,799,336?

Claim 1 has potentially broad genus coverage because “prostamide component” is not limited to bimatoprost. Claim 5 supplies a detailed chemical genus, while claim 4 separately identifies bimatoprost.

The claim can potentially read on an implant even where:

The prostamide is incorporated in a microsphere, rod, pellet or other matrix form.
The matrix contains one biodegradable polymer or multiple polymers.
The implant is placed in the vitreous, anterior chamber or another ocular location.
The release lasts only slightly longer than one week.
The product is intended for intraocular pressure reduction or another ocular indication.

The principal limiting concept is sustained therapeutic release. “At least about one week” creates both a duration limitation and a potential claim-construction issue. The phrase “about” introduces tolerance around the one-week period, but it does not eliminate the need for evidence that the release profile satisfies the claim.

The phrase “rate effective to sustain release of a therapeutically effective amount” also introduces functional limitations. In litigation, infringement would likely turn on product testing, release studies, pharmacodynamic data and the meaning of “therapeutically effective amount” for the accused indication.

What prostamides and formulations are protected?

Bimatoprost

Claim 4 expressly covers bimatoprost in a broad concentration range of approximately 0.1% to 90% by implant weight. The range is unusually broad from a formulation perspective. It covers low-loading implants as well as highly drug-loaded matrices, subject to the remaining claim requirements.

The claim does not require a particular bimatoprost polymorph, particle size, excipient, stabilizer or implant geometry. Those details may be relevant to other patents, regulatory specifications or infringement analysis, but they are not express limitations of claim 4.

Chemical prostamide genus

Claim 5 uses a Markush structure covering compounds with variable:

Unsaturation and cis/trans configuration.
Alkylene or alkenylene side chains.
Cycloalkyl, aryl and heteroaryl groups.
Alcohol, amine and related terminal groups.
Oxidized or reduced ring structures.
Ester and acyl substituents.
Pharmaceutically acceptable salts.

The proviso concerning the B, Z and X substituents narrows the genus in a defined structural circumstance. That proviso matters for claim construction and validity because the claim cannot be read as covering every compound that otherwise fits the general substituent definitions.

A competitor using a prostamide outside the claim 5 genus may avoid literal infringement of that dependent claim while remaining exposed under claim 1 if the compound qualifies as a “prostamide component.”

Polymer matrix

Claims 6 through 10 focus on biodegradable matrices based on:

Polylactic acid.
Polyglycolic acid.
Polylactide-co-glycolide.
Derivatives and mixtures of those polymers.

The claims protect polymer blending as a release-control strategy. They are not limited to a single molecular weight, inherent viscosity or polymer ratio. Claims 9 and 10 are particularly relevant where a manufacturer uses polymers selected to produce staged degradation, controlled diffusion or a longer release period.

What technical manufacturing methods are covered?

Claim 17 covers an implant formed by extrusion. Extrusion claims can be important where the product is manufactured as a continuous polymer-drug rod and subsequently cut into implant units.

The claim does not specify:

Extrusion temperature.
Screw configuration.
Die geometry.
Residence time.
Drug-polymer mixing order.
Post-extrusion curing.
Implant dimensions.

A product made by injection molding, compression molding, solvent casting or another process may avoid claim 17 while remaining within claims 1 or 6 through 16.

Manufacturing risks remain significant because process evidence can be obtained from regulatory filings, supplier records, batch records, equipment specifications and technical disclosures. A non-infringing process does not avoid the product claims if the resulting implant satisfies claim 1.

When does US 7,799,336 lose exclusivity?

US 7,799,336 was issued on September 21, 2010. Its enforceable term is governed by the 20-year term measured from the applicable earliest nonprovisional U.S. filing date, subject to patent-term adjustment and any terminal disclaimer. The relevant priority and prosecution history must be used to calculate the exact expiration date under 35 U.S.C. §§ 154 and 156.

The patent’s term is therefore not determined solely by the issue date. A practical freedom-to-operate review should examine:

The earliest U.S. nonprovisional filing date.
Any continuation or divisional relationship.
Patent-term adjustment.
Terminal disclaimers.
Patent-term extension.
Whether related continuation patents remain in force.
Whether any claim was canceled, disclaimed or held unenforceable.

Based on the patent’s historical filing period, the ordinary 20-year term would place expiration in the mid-2020s, before adjustment. The patent should not be treated as the only relevant barrier to a current product launch. Related patents and later continuation patents may have materially later expiration dates.

What is the Orange Book status of US 7,799,336?

Orange Book relevance depends on the approved drug product and the NDA holder’s listing decision. A patent may be technically relevant to an intraocular implant without appearing in the Orange Book for every product that uses the same active ingredient.

For an approved bimatoprost implant, the relevant questions are:

Orange Book issue	Impact
Listed patent	May support a Paragraph IV certification or a later patent certification
Unlisted patent	May still support infringement litigation, but generally does not create the same listed-patent ANDA delay mechanism
Use code	Determines whether a method-of-use patent is relevant to the proposed ANDA labeling
Product claim	More directly relevant to an ANDA product containing the patented implant
Expired listing	Does not independently block approval, although other patents may remain
Patent-term extension	Can extend eligible FDA-regulated patent rights beyond the ordinary term

The FDA Orange Book should be checked by NDA, product name and patent number, not only by active ingredient. For an intraocular implant, the regulatory product may be listed under a product-specific NDA rather than under ophthalmic bimatoprost drops.

Are Paragraph IV challenges likely for this patent?

A Paragraph IV challenge would be relevant if the patent is listed for an approved product and an ANDA applicant seeks approval of a product that could fall within a listed claim.

Potential Paragraph IV positions include:

Noninfringement: The proposed product does not contain a prostamide matrix implant within claim 1.
No sustained release: The product does not release a therapeutic amount for at least approximately one week.
Different delivery technology: The product uses a non-biodegradable reservoir or a different implant architecture.
Invalidity for anticipation: Earlier prostaglandin or prostamide implants disclose all elements of a claim.
Invalidity for obviousness: A skilled formulator would have combined a known prostamide with a known biodegradable ocular matrix.
Indefiniteness: Terms such as “about one week,” “therapeutically effective amount” or “rate effective” may be challenged if the specification does not provide objective boundaries.
Written-description or enablement: The broad prostamide and polymer genera may be challenged if the disclosure does not support the full claim breadth.

A Paragraph IV challenge is product-specific. A generic ophthalmic solution containing bimatoprost would generally not practice the implant limitations. A competing biodegradable bimatoprost implant would face substantially greater exposure.

What patent litigation affects US 7,799,336?

The patent should be analyzed with the full family and related implant patents. Product litigation may involve patents directed to:

The active prostamide.
The biodegradable implant matrix.
Bimatoprost loading and release.
Implant dimensions and placement.
Manufacturing processes.
Combination therapy.
Specific glaucoma treatment methods.
Device applicators and delivery systems.

A patent-number-only search can miss litigation filed against a product under a continuation patent or a different family member. Litigation status should be confirmed through PACER, USPTO Patent Center, FDA Orange Book records and the patent family’s prosecution history.

No conclusion that the patent is enforceable, litigated or commercially blocking should be based on claim text alone. Enforceability also depends on maintenance fees, disclaimers, terminal disclaimers, prosecution amendments, prior-art submissions and any court judgment.

How does US 7,799,336 compare with competing glaucoma implant estates?

Product or platform	Active drug	Delivery technology	Relationship to US 7,799,336
Bimatoprost biodegradable implant platforms	Bimatoprost	Biodegradable intraocular matrix	Highest potential overlap
Durysta	Bimatoprost	Biodegradable intracameral implant	Product-specific patent and regulatory review required
Ozurdex	Dexamethasone	Biodegradable intravitreal implant	Similar matrix concept, different active drug and indication
Iluvien	Fluocinolone acetonide	Non-biodegradable intravitreal reservoir	Generally outside prostamide claims
Retisert	Fluocinolone acetonide	Non-biodegradable intravitreal device	Generally outside claim 1’s prostamide requirement
iDose	Travoprost	Non-biodegradable titanium reservoir	Different drug and delivery architecture
Ophthalmic bimatoprost solution	Bimatoprost	Topical solution	Does not contain the claimed implant matrix

Durysta is the closest commercial comparator because it combines bimatoprost with a biodegradable intraocular implant. However, infringement cannot be determined from the active ingredient alone. The relevant questions are the implant matrix, release duration, placement site, formulation and applicable patent family.

How strong is the patent estate?

The estate has its strongest position against a biodegradable sustained-release prostamide implant that:

Uses bimatoprost.
Uses a polylactic acid, polyglycolic acid or PLGA matrix.
Releases drug for more than one week.
Is placed intraocularly.
Uses blended polymers with different molecular weights or viscosities.
Is manufactured by extrusion.

The estate is weaker against:

Topical bimatoprost formulations.
Non-biodegradable reservoirs.
Implants containing a non-prostamide drug.
Devices that release drug for less than the claim duration.
Products using materially different chemistry outside the claim 5 genus.
Products that deliver drug through a separate pump or reservoir rather than a biodegradable polymer matrix.

The broad genus claims create potential validity exposure. Earlier biodegradable ocular implants and prostaglandin delivery systems are the most relevant prior-art categories. The dependent claims provide fallback positions because they add commercially concrete limitations such as bimatoprost, PLGA blends, vitreous placement and extrusion.

What generic launch scenarios exist?

Scenario 1: Topical bimatoprost generic

A conventional ophthalmic solution is unlikely to practice the implant limitations. US 7,799,336 would generally be a low-risk patent for that product, although separate formulation, method-of-use and active-ingredient patents could apply.

Scenario 2: Biodegradable bimatoprost implant

This is the highest-risk scenario. A product using a biodegradable polymer matrix and sustained release beyond one week could fall within claim 1 and claim 4. Claims 6 through 11 could create additional exposure if the formulation uses polymer blends or exceeds one month of release.

Scenario 3: Non-biodegradable bimatoprost reservoir

The product may avoid the biodegradable matrix limitation. It could still face separate device, drug-release or method-of-treatment patents.

Scenario 4: Alternative prostamide

An alternative prostamide may avoid claim 4 but remain within claims 1, 2 or 5. Chemical mapping against the Markush structure is required.

Scenario 5: Different glaucoma drug

An implant containing travoprost, latanoprost, timolol or another non-prostamide drug generally would not satisfy claim 1’s prostamide requirement. Separate patents may cover those products.

What geographic coverage does the patent provide?

US 7,799,336 provides rights in the United States only. Foreign protection depends on corresponding national or regional patents, including potential filings in:

Europe.
Canada.
Japan.
Australia.
China.
South Korea.
India.

Foreign family members may have different claim scope, expiration dates, prosecution amendments and validity outcomes. A U.S. expiration date does not establish freedom to operate in Europe or other markets.

Key Takeaways

US 7,799,336 targets biodegradable intraocular implants containing prostamides.
Claim 1 is the principal broad product claim.
Claim 4 directly covers bimatoprost implants with 0.1% to 90% loading by weight.
Claims 6 through 10 protect polymer mixtures, including PLA, PGA and PLGA combinations.
Claim 11 strengthens coverage for implants releasing prostamide for more than one month in the vitreous.
Claim 17 covers extrusion-made implants but does not control products made by other processes.
A biodegradable sustained-release bimatoprost implant presents the highest infringement risk.
A topical bimatoprost generic generally falls outside the claimed implant technology.
The patent’s ordinary term is tied to its earliest applicable nonprovisional filing date, not its 2010 issue date.
Current freedom-to-operate analysis must include continuation patents, Orange Book listings, terminal disclaimers, maintenance status and litigation records.

FAQs About US Patent 7,799,336

Does US 7,799,336 cover Durysta?

It may be relevant because Durysta is a biodegradable bimatoprost intraocular implant. Coverage depends on the product’s formulation, matrix, release profile, placement and the surviving claims and related patent family.

Does the patent cover bimatoprost eye drops?

No. The asserted claims require an intraocular implant and biodegradable polymer matrix. A conventional topical solution does not ordinarily satisfy those limitations.

Does a one-month bimatoprost implant face greater risk than a one-week implant?

Yes. A product releasing prostamide for more than one month in the vitreous may implicate claim 11 in addition to the broader limitations of claim 1.

Can changing the polymer avoid infringement?

It may. A polymer outside the claimed biodegradable polymer categories could avoid claims 6 through 10, but claim 1 is broader and does not limit the matrix to a specified polymer.

Is a foreign patent family member automatically expired when the U.S. patent expires?

No. Each jurisdiction applies its own term, patent-term adjustment or extension rules, prosecution history and maintenance requirements. Foreign family members require separate review.

References

U.S. Patent No. 7,799,336, “Biodegradable intraocular implants containing prostamides.” U.S. Patent and Trademark Office.
U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations (Orange Book).
U.S. Patent and Trademark Office. (2024). Manual of Patent Examining Procedure, §§ 2106, 2111, 2161 and 2701.
35 U.S.C. §§ 154, 156, 271 and 282.
U.S. Food and Drug Administration. (2020). Durysta label. NDA 213006.
U.S. Food and Drug Administration. (2023). iDose TR label. NDA 214690.

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Patented / Exclusive Use	Submissiondate
Abbvie	DURYSTA	bimatoprost	IMPLANT;OPHTHALMIC	211911-001	Mar 4, 2020		RX	Yes	Yes	⤷ Start Trial	⤷ 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

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Austria	E397934	⤷ Start Trial
Australia	2005244203	⤷ Start Trial
Australia	2007223057	⤷ Start Trial
>Country	>Patent Number	>Estimated Expiration	>Supplementary Protection Certificate	>SPC Country	>SPC Expiration

Details for Patent: 7,799,336

Which drugs does patent 7,799,336 protect, and when does it expire?

Summary for Patent: 7,799,336