United States Patent 9,345,771: Dronabinol Oral Solution Claims, Exclusivity, and Patent Landscape

US Patent 9,345,771 protects a specific liquid dronabinol formulation associated with Syndros, including a high-alcohol aqueous solution containing polyethylene glycol 400, propylene glycol, preservatives, and optional sweetener. The patent’s strongest commercial coverage is directed to a 5% w/w dronabinol formulation with approximately 50% alcohol, 30% to 33% water, 12% polyethylene glycol 400, and 5.5% propylene glycol.

The patent has several material limitations. The claims require narrow quantitative ranges, selected excipients, and pharmacokinetic characteristics. Claims 9 and 10 also present a drafting issue because the listed ingredients exceed 100% w/w before accounting for certain added excipients. The patent is associated with FDA-approved Syndros, a dronabinol oral solution, and its statutory expiration is generally calculated around January 25, 2033, subject to any applicable patent-term adjustment or extension reflected in official USPTO records. [1][2][3]

What does US Patent 9,345,771 protect?

The patent protects an oral liquid pharmaceutical composition containing dronabinol and a defined solvent system.

Core claim elements

Claim 1 requires all of the following:

Element	Claimed requirement
Active ingredient	Dronabinol
Dronabinol concentration	0.1% to 5% w/w
Water	25% to 33% w/w
Solvent	15% to 65% w/w
Propylene glycol	5.5% w/w
Polyethylene glycol	12% w/w
Preservative or stabilizer	BHA, BHT, EDTA, a paraben, or combination
Stability	At least 18 months at room or refrigerated temperature
Absorption variability	Less than 50% in vivo
Pharmacokinetics	Defined Cmax, AUC, Tmax, or related parameters
Dosage form	Liquid for oral consumption

The claim is a composition claim, but it also incorporates performance limitations. A competing product would need to satisfy the formulation limitations and the stated stability or pharmacokinetic limitations to fall within the literal scope of claim 1.

The patent does not broadly cover every dronabinol liquid. A liquid containing dronabinol in a different solvent system, without the specified polyethylene glycol and propylene glycol quantities, or with materially different water content could fall outside claim 1.

How do the dependent claims narrow the patent scope?

Claims 2 through 12 create multiple formulation and performance branches.

Claim	Subject matter
1	Broadest independent formulation claim
2	Requires 50% solvent
3	Requires ethanol as the solvent
4	Requires sublingual spray form
5	Independent formulation claim with defined PK profile
6	Adds AUC infinity, half-life, or elimination-rate limitations
7	Requires 5% w/w dronabinol
8	Requires 30% to 33% w/w water
9	Specifies dronabinol, PEG 400, propylene glycol, water, and 50% alcohol
10	Adds BHA, sucralose, methyl paraben, and propyl paraben
11	Requires 0.01% BHA or EDTA
12	Requires 0.05% sweetener

Claims 7 through 10 are the commercially important cluster because they approach the formulation used for Syndros. Claims 9 and 10 are more product-specific than claim 1 and may provide useful infringement positions against a generic that copies the branded formulation.

What is the commercial formulation associated with US 9,345,771?

Syndros is a dronabinol oral solution approved by the FDA under NDA 205525. The FDA label identifies dronabinol oral solution as a 5 mg/mL product and lists excipients that correspond closely to the patent’s formulation architecture, including alcohol, polyethylene glycol 400, propylene glycol, water, BHA, sucralose, methylparaben, and propylparaben. [2]

The formulation is designed to avoid the absorption variability associated with oral dronabinol capsules. Marinol, the earlier dronabinol product, is an oral capsule. Syndros uses a liquid delivery system with a solvent and cosolvent combination intended to solubilize dronabinol and provide more consistent exposure.

Formulation comparison

Product or formulation	Dosage form	Key formulation characteristics	Relationship to US 9,345,771
Syndros	Oral solution	5 mg/mL dronabinol; alcohol, PEG 400, propylene glycol, water, preservatives, sweetener	Closely aligned
Marinol	Oral capsule	Dronabinol in sesame-oil-based capsule formulation	Different dosage form and excipient platform
Generic dronabinol capsules	Oral capsule	Generally based on capsule formulation	Less direct formulation overlap
Competing oral liquid	Oral solution	Depends on solvent, water, excipients, and concentration	Potentially exposed if it copies claimed ranges

What are the strongest claims in US 9,345,771?

Claims 1, 5, 7, 9, and 10 are the principal enforcement claims.

Claim 1 has the broadest ingredient ranges but also carries the greatest burden of proof because it requires stability and pharmacokinetic characteristics. Claim 5 is independent and focuses on a defined 5 mg dose and pharmacokinetic profile. Claim 7 narrows claim 1 to 5% w/w dronabinol. Claim 9 recites the primary composition. Claim 10 adds the preservative and sweetener package.

Claim 9 is potentially powerful against a copycat product because it identifies the commercially relevant concentration and solvent system. A generic that uses 5% dronabinol, 12% PEG 400, 5.5% propylene glycol, 30% to 33% water, and 50% alcohol could face a direct infringement theory if the claim is construed as covering those quantities.

Claims 11 and 12 have narrower value. Claim 11 addresses a 0.01% BHA or EDTA level. Claim 12 addresses a 0.05% sweetener level. These claims may capture formulation variants that avoid the more detailed claim 10 combination.

Are claims 9 and 10 internally consistent?

Claims 9 and 10 raise a material claim-construction issue because the listed w/w percentages appear to exceed 100%.

Claim 9 recites:

5% dronabinol
12% polyethylene glycol 400
5.5% propylene glycol
30% to 33% water
50% alcohol

The total is 102.5% to 105.5% w/w before accounting for any additional ingredient. Claim 10 adds BHA, sucralose, methylparaben, and propylparaben, increasing the apparent total further.

This inconsistency may result from one or more drafting conventions:

The “50% alcohol” figure may have been intended as a volume percentage rather than a weight percentage.
The water range may have been intended as a residual or approximate quantity.
The formulation percentages may have been copied from a manufacturing composition using different measurement bases.
The claims may contain an arithmetic or drafting error.

The inconsistency does not automatically eliminate the patent. Courts construe claims in light of the specification, prosecution history, and technical meaning. A court could treat the percentages as approximate, construe alcohol on a different basis, or determine that the claim is indefinite if a skilled person cannot identify a workable composition. The issue creates greater vulnerability for claims 9 and 10 than for claim 1, which provides broader ranges.

What patent expiration date applies to US 9,345,771?

US Patent 9,345,771 was issued on May 24, 2016. Its term is generally calculated from the earliest effective nonprovisional filing date, not from the issue date. Public patent records associate the patent family with a January 2012 priority period and a U.S. filing date in January 2013. On that basis, the nominal expiration is approximately January 25, 2033. [1]

Milestone	Date or period
Earliest associated priority period	January 2012
U.S. filing period	January 2013
Patent issued	May 24, 2016
Nominal term endpoint	Approximately January 25, 2033
Potential adjustments	PTA, PTE, terminal disclaimer, or other USPTO-recorded adjustment

Patent expiration must be separated from FDA regulatory exclusivity. The patent term may continue after FDA exclusivity ends. Conversely, FDA approval does not extend the patent unless a patent-term extension is granted under the Hatch-Waxman framework. [3][4]

What is the Orange Book status of US 9,345,771?

US 9,345,771 is associated with Syndros and has been treated as an Orange Book-listed patent for the product. Orange Book listing is commercially significant because an ANDA applicant referencing Syndros must address listed patents through a Paragraph III certification, Paragraph IV certification, or other applicable certification under the Hatch-Waxman statute. [3][4]

A Paragraph IV certification would assert that the patent is invalid, unenforceable, or not infringed. If the NDA holder brings suit within the statutory period after receiving notice, FDA approval of the ANDA may be stayed for up to 30 months, subject to statutory exceptions and court developments. [3]

When does dronabinol generic entry become possible?

Dronabinol capsule competition is distinct from competition against Syndros oral solution.

A generic capsule applicant may avoid the formulation claims in US 9,345,771 because the patent is directed to a liquid solution. A generic oral solution would face greater risk if it uses the claimed solvent and excipient system.

Potential entry scenarios include:

Entry scenario	Patent risk
Generic dronabinol capsule	Lower direct risk under this patent
Oral solution with different solvent	Potential design-around
Oral solution using ethanol but different PEG or propylene glycol levels	Possible noninfringement position
Oral solution matching 5% dronabinol and excipient package	High exposure
Sublingual spray using the claimed composition	Potential exposure under claim 4
Product with different PK profile	May avoid some performance-limited claims, but not necessarily composition claims

A Paragraph IV challenge could attack the patent based on obviousness, lack of enablement, indefiniteness, written-description concerns, or noninfringement. The numerical inconsistency in claims 9 and 10 provides a possible litigation issue, but it would not necessarily invalidate claim 1 or the other claims.

Which companies are challenging the patent?

The claims and patent number provided do not establish a specific current Paragraph IV challenger, ANDA filer, litigation defendant, or settlement agreement. The public landscape is instead defined by the distinction between capsule-based dronabinol generics and liquid oral-solution products.

No biosimilar pathway applies. Dronabinol is a small-molecule active pharmaceutical ingredient, so competing products would generally proceed through an ANDA or, in some cases, a 505(b)(2) application rather than the biosimilar pathway under the Public Health Service Act.

How strong is the patent estate for Syndros?

The patent is strongest against a formulation that copies the branded product’s quantitative composition. Its commercial value depends on four factors:

The liquid dosage form differentiates it from capsule-based dronabinol products.
The excipient system is specific enough to support formulation-focused enforcement.
The PK and stability limitations provide product-performance coverage but create proof and construction issues.
The claims contain numerical inconsistencies that could weaken the narrower formulation claims.

The estate is less effective against a technically distinct oral solution. A competitor could seek to vary the alcohol concentration, replace PEG 400, modify propylene glycol, use a different preservative system, or develop a non-liquid dosage form.

What manufacturing and IP barriers affect a competing oral solution?

A competitor must solve more than dronabinol solubility. Key technical barriers include:

Maintaining a stable dronabinol concentration over the labeled shelf life.
Controlling precipitation during storage and temperature changes.
Achieving acceptable taste and patient adherence.
Preserving dose uniformity in a multi-dose liquid container.
Demonstrating reproducible exposure in fed and fasted conditions.
Establishing microbial and preservative control.
Avoiding the claimed combination of alcohol, PEG 400, propylene glycol, water, and preservatives.

A formulation that avoids one ingredient may create new regulatory or manufacturing problems. A different solvent may alter tolerability, flammability, extractables, container compatibility, or bioavailability.

How does US 9,345,771 compare with Marinol patent protection?

Marinol and Syndros occupy different formulation categories.

Issue	Marinol	Syndros and US 9,345,771
Active ingredient	Dronabinol	Dronabinol
Dosage form	Capsule	Oral solution
Formulation platform	Oil-based capsule	Alcohol-water solvent system
Primary competition	Generic capsules	Generic oral solutions and 505(b)(2) products
Patent relevance	Legacy capsule and use patents	Liquid formulation patents
Biosimilar risk	None	None

The existence of generic dronabinol capsules does not establish freedom to market a liquid oral solution. Conversely, the liquid formulation patent does not block all capsule products.

Key Takeaways

US 9,345,771 is directed to a dronabinol oral solution with defined solvent, cosolvent, water, preservative, stability, and PK limitations.
The commercially important formulation is approximately 5% dronabinol, 50% alcohol, 30% to 33% water, 12% PEG 400, and 5.5% propylene glycol.
Claims 9 and 10 closely track the branded formulation but appear to exceed 100% w/w when their listed percentages are added.
The patent is associated with Syndros and is relevant to Orange Book-based ANDA certification analysis.
The nominal patent expiration is approximately January 25, 2033, subject to official term adjustments.
Generic capsule products present less direct risk than competing oral solutions.
No biosimilar pathway applies because dronabinol is a small-molecule drug.
A design-around could vary the solvent, cosolvent, preservative system, concentration, or dosage form.
The patent’s strongest commercial leverage is against a product that reproduces the Syndros formulation rather than against all dronabinol products.

FAQs About US Patent 9,345,771 and Dronabinol Exclusivity

Does US 9,345,771 cover Marinol capsules?

No. The claims are directed to a liquid oral solution. Marinol capsules use a different dosage form and formulation platform.

Can a generic dronabinol oral solution avoid this patent?

Yes, potentially. A product may seek to avoid infringement by changing the solvent system, PEG 400 level, propylene glycol level, water content, preservative system, or dosage form. The product would still require FDA approval.

Is US 9,345,771 a method-of-use patent?

No. The provided claims are composition and dosage-form claims. They do not claim treatment of a specific disease or patient population as the principal subject matter.

Does a 505(b)(2) application eliminate the patent risk?

No. A 505(b)(2) applicant may still need to address applicable Orange Book patents and may face infringement litigation based on the proposed formulation or labeling.

Can the apparent percentage error invalidate the entire patent?

No. The issue primarily affects construction and validity analysis for the claims containing the inconsistent percentages. Other claims may remain enforceable if they can be construed and supported independently.

References

United States Patent and Trademark Office. (2016). U.S. Patent No. 9,345,771, pharmaceutical composition comprising dronabinol.
U.S. Food and Drug Administration. (2017). Syndros (dronabinol) oral solution prescribing information.
U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations: Orange Book.
U.S. Code, 21 U.S.C. §§ 355 and 156. Federal Food, Drug, and Cosmetic Act: Abbreviated new drug applications and patent-term extension.

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Patented / Exclusive Use	Submissiondate
Wellhouse Pharma	SYNDROS	dronabinol	SOLUTION;ORAL	205525-001	Mar 23, 2017		DISCN	Yes	No	⤷ Start Trial	⤷ Start Trial	Y	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

Details for Patent: 9,345,771

Which drugs does patent 9,345,771 protect, and when does it expire?

Summary for Patent: 9,345,771