United States Drug Patent 7,935,690: Claim Scope, Patent Landscape, and Generic Entry Risk

U.S. Patent No. 7,935,690 protects a transdermal androgen gel method defined by a narrow combination of formulation and use limitations. The independent claim requires treatment of male hypogonadism, maintenance of therapeutically effective serum androgen levels, topical application, a specified viscosity and pH, ethanol, a thickener, and one of five named macrocyclic penetration enhancers. The patent does not broadly cover every testosterone gel.

The principal commercial risk is formulation-specific. A testosterone gel that uses a conventional enhancer, omits the claimed macrocyclic compound, falls outside the claimed ethanol or viscosity ranges, or is not used for treating male hypogonadism may avoid literal infringement of claim 1. Claims 2-16 add narrower formulation limitations and do not materially broaden the protected technology.

What does U.S. Patent 7,935,690 protect?

The patent protects a method of maintaining a therapeutically effective androgen concentration in the blood serum of a male with hypogonadism by applying a defined topical gel to the skin.

Independent claim 1 requirements

An accused product or process must satisfy every material limitation of claim 1 for literal infringement:

Claim element	Required scope
Patient	Male
Indication	Treatment of hypogonadism
Pharmacologic objective	Maintaining a therapeutically effective androgen concentration in blood serum
Route	Transdermal delivery through skin
Dosage form	Topical gel
Viscosity	About 500 to about 20,000 cps
pH	About 3 to about 9
Androgen concentration	About 0.1 to about 5 wt.%
Androgen	Testosterone, DHEA, pregnenolone, progesterone, 17-OH-progesterone, or androsterone
Macrocyclic enhancer	About 8 to about 25 wt.%
Enhancer identity	One of five specified macrocyclic compounds or a mixture
Thickener	About 0.1 to about 10 wt.%
Solvent system	Mixture of solvents including about 40 to about 80 wt.% ethanol

The claim is cumulative. A formulation containing testosterone and ethanol is not enough. It must also contain the claimed macrocyclic enhancer, thickener, gel characteristics, and concentration ranges, and the method must be directed to the claimed therapeutic use.

What are the five claimed macrocyclic enhancers?

Claim 1 covers the following Markush group:

3-methylcyclopentadecanone
9-cycloheptadecen-1-one
Cyclohexadecanone
Cyclopentadecanone
Oxacyclohexadecan-2-one

The dependent claims isolate each enhancer individually. Claim 12 covers oxacyclohexadecan-2-one; claim 13 covers 3-methylcyclopentadecanone; claim 14 covers 9-cycloheptadecen-1-one; claim 15 covers cyclohexadecanone; and claim 16 covers cyclopentadecanone.

How do claims 2 through 16 narrow the patent?

Claims 2-16 are dependent claims. They incorporate all limitations of claim 1 and add further restrictions.

Claim	Additional limitation
2	Polyethylene glycol
3	Polyethylene glycol at about 0.001 to about 5 wt.%
4	Viscosity of about 1,000 to about 9,000 cps
5	Viscosity of about 2,000 to about 8,000 cps
6	Viscosity of about 3,000 to about 7,000 cps
7	pH of about 4 to about 8
8	Ethanol at about 50 to about 75 wt.%
9	Ethanol at about 60 to about 75 wt.%
10	Claim 9 composition further includes propylene glycol
11	Claim 10 composition further includes glycerin
12	Macrocyclic enhancer is oxacyclohexadecan-2-one
13	Macrocyclic enhancer is 3-methylcyclopentadecanone
14	Macrocyclic enhancer is 9-cycloheptadecen-1-one
15	Macrocyclic enhancer is cyclohexadecanone
16	Macrocyclic enhancer is cyclopentadecanone

The most commercially specific claims are claims 9-11 and claims 12-16. Claims 9-11 capture high-ethanol gels containing propylene glycol and, in claim 11, glycerin. Claims 12-16 focus on the enhancer identity rather than a particular solvent package.

What formulation ranges create the main infringement boundary?

The key boundaries are concentration, viscosity, pH, and solvent content.

Androgen concentration

The claimed androgen range is about 0.1 to about 5 wt.%. A conventional 1% testosterone gel falls numerically within this range. Concentration alone therefore does not distinguish a product from the claim.

The androgen must also be one of the six listed compounds. A different androgen or a non-androgen active ingredient would not satisfy this limitation literally.

Macrocyclic enhancer concentration

The enhancer must be present at about 8 to about 25 wt.%. This is a substantial formulation requirement. A product using a listed enhancer at a lower concentration may create a noninfringement position, although the interpretation of "about" and the doctrine of equivalents would remain relevant.

The enhancer identity is more important than the general concept of permeation enhancement. Carbomer, isopropyl myristate, oleic acid, lauryl alcohol, propylene glycol, and ordinary alcohol-based penetration systems are not among the listed macrocyclic compounds.

Ethanol concentration

Claim 1 requires about 40 to about 80 wt.% ethanol. Claims 8 and 9 narrow that range to 50-75 wt.% and 60-75 wt.%, respectively.

This limitation creates a potentially meaningful design-around path. A formulation using less than approximately 40 wt.% ethanol, or no ethanol, would have a strong literal noninfringement argument against claim 1. Claims 8-9 would be narrower still.

Viscosity

Claim 1 covers about 500-20,000 cps. Claims 4-6 narrow the range progressively:

Claim 4: 1,000-9,000 cps
Claim 5: 2,000-8,000 cps
Claim 6: 3,000-7,000 cps

A low-viscosity solution, spray, aerosol, foam, patch, or lotion may avoid the "topical gel" and viscosity limitations. A gel within the claimed ranges creates greater risk, particularly if it also contains a listed macrocyclic enhancer.

pH

Claim 1 covers pH 3-9. Claim 7 narrows this to pH 4-8. Because most skin-applied gels are formulated near a skin-compatible pH, pH is unlikely to be the primary design-around feature. It remains relevant for claim-by-claim analysis.

How strong is the patent estate for U.S. Patent 7,935,690?

The patent has a focused claim set rather than a broad platform claim. Its strength depends on whether a competing product uses the complete combination.

Strengths

The patent has several features that can make claim 1 difficult to avoid unintentionally:

The claims combine composition and therapeutic-use limitations.
The macrocyclic enhancer group is chemically specific.
The claim covers a relatively broad ethanol range.
The claim includes multiple formulation characteristics: gel form, viscosity, pH, thickener, androgen, enhancer, and solvent system.
Dependent claims provide fallback positions for narrower viscosity and solvent ranges.
Claims 12-16 separately preserve each named enhancer.

A product developer that selects one of the listed macrocyclic enhancers at 8-25 wt.% and combines it with a 0.1-5 wt.% androgen gel containing 40-80 wt.% ethanol may encounter substantial claim overlap.

Weaknesses

The claims also have important limitations:

They are method claims, not unrestricted composition claims.
The method is limited to treatment of hypogonadism in a male.
The androgen must come from a closed list.
The enhancer must come from a closed list.
The enhancer concentration is limited to 8-25 wt.%.
The formulation must be a topical gel.
The viscosity and pH must fall within specified ranges.
The solvent mixture must include 40-80 wt.% ethanol.
The claims do not cover all transdermal delivery systems or all testosterone formulations.

The therapeutic-use limitation may be material in a product-liability or induced-infringement analysis. Product labeling, prescribing information, promotional materials, dosing instructions, and the approved indication would be relevant evidence.

What is the likely patent term and expiration status?

U.S. Patent No. 7,935,690 issued on May 3, 2011. U.S. utility patents generally receive a term measured from the earliest effective nonprovisional filing date, subject to patent-term adjustment, patent-term extension, terminal disclaimers, and other statutory adjustments under 35 U.S.C. § 154.

The issue date does not establish the expiration date. The controlling analysis requires the patent’s priority chain, any terminal disclaimer, patent-term adjustment, and maintenance-fee status. The USPTO Patent Center record and patent-term data should control the operative expiration calculation.[1][2]

For commercial diligence, the patent should be treated as a term-sensitive right rather than an assumed active barrier. If the earliest effective nonprovisional filing date was more than 20 years before the relevant launch date, ordinary patent term may have ended absent a qualifying adjustment. A current freedom-to-operate opinion should verify the live legal status and any terminal disclaimer before relying on the patent as an enforceable barrier.

Is U.S. Patent 7,935,690 listed in the Orange Book?

The claims are method claims directed to a topical androgen treatment. Orange Book listing depends on whether the patent was submitted for an approved drug and accepted by FDA under the applicable patent-listing rules. Patent ownership or subject-matter relevance alone does not establish Orange Book listing.

FDA’s Orange Book identifies patents and exclusivity associated with approved drug products, including certain formulation, drug-substance, and method-of-use patents. The relevant analysis must match the patent to an approved product, active ingredient, dosage form, strength, and labeling.[3]

A patent may affect infringement risk without appearing in the Orange Book. Conversely, an Orange Book listing does not establish validity or enforceability. For an abbreviated new drug application, a Paragraph IV certification would be relevant only if the patent is listed against the applicable reference-listed drug and remains legally relevant to the proposed ANDA product.

What Paragraph IV challenges could target this patent?

A Paragraph IV challenge could attack the patent on several grounds:

Anticipation

The challenger would seek a single prior-art reference disclosing every element of claim 1, including:

The specified androgen;
A topical gel;
The claimed macrocyclic enhancer;
The enhancer concentration;
The ethanol range;
The thickener;
The viscosity;
The pH; and
Treatment of male hypogonadism by maintaining effective serum androgen levels.

A prior-art testosterone gel without the listed macrocyclic enhancer would likely not anticipate the complete claim.

Obviousness

Obviousness would be the more significant validity theory. A challenger could combine prior art relating to:

Testosterone or another listed androgen;
Alcohol-based transdermal gels;
Macrocyclic penetration enhancers;
Thickened topical vehicles;
Skin-compatible pH;
Serum testosterone maintenance; and
Treatment of hypogonadism.

The strongest obviousness case would need a reason to select the claimed macrocyclic enhancer and concentration range, not merely a general motivation to improve transdermal absorption. Unexpected permeation, improved serum exposure, reduced variability, or improved tolerability could support patentability if adequately documented in the prosecution record.

Written description and enablement

The Markush group covers several chemically distinct macrocyclic compounds and multiple androgens. A challenger could examine whether the specification adequately supports the full genus and enables the claimed ranges without undue experimentation.

The risk is lower if the specification contains working examples for each enhancer and multiple androgen formulations. It is higher if the examples focus on only one enhancer or one testosterone formulation while the claims cover the entire listed group.

Indefiniteness and claim construction

Terms such as "about," "therapeutically effective concentration," "maintaining," and "topical gel" may require construction. They are not automatically indefinite, but their scope can affect both infringement and validity.

The viscosity limitation also raises measurement questions. Temperature, spindle, shear rate, and test method can affect the reported cps value. A product specification should be evaluated using a consistent and technically appropriate measurement protocol.

Which competing testosterone products are most relevant?

The relevant competitive landscape includes testosterone gels, topical testosterone solutions, nasal testosterone, patches, injections, and oral testosterone products.

Product or technology	Typical delivery concept	Relevance to Patent 7,935,690
AndroGel	Alcohol-based topical testosterone gel	Potential overlap depends on enhancer identity and formulation details
Testim	Topical testosterone gel	Potential overlap depends on whether a listed macrocyclic enhancer is used
Fortesta	Topical testosterone gel	Gel and testosterone may overlap, but enhancer and concentration limitations control
Vogelxo	Generic testosterone gel	ANDA product composition, labeling, and Orange Book patents require separate analysis
Axiron	Topical testosterone solution applied to the axilla	May avoid the topical-gel limitation if the formulation is legally characterized as a solution
Natesto	Intranasal testosterone gel	Does not use transdermal skin delivery and is outside the central route limitation
Testosterone patches	Transdermal patch systems	Generally outside the topical-gel limitation
Injectable testosterone	Intramuscular or subcutaneous delivery	Outside the transdermal route and topical-gel limitations
Oral testosterone products	Oral systemic delivery	Outside the claimed transdermal method

The presence of testosterone, ethanol, or a thickener in a competing product is not sufficient to establish overlap. The listed macrocyclic enhancer is the principal technical discriminator.

What formulation patents compete with this patent?

The broader testosterone patent landscape generally includes four categories:

Testosterone gel composition patents

These patents cover gel vehicles, alcohol systems, penetration enhancers, testosterone concentration, rheology, and skin delivery. AndroGel and Testim-related patent families are representative examples of this category.

Method-of-use patents

Method claims may cover treatment of hypogonadism, dosing regimens, serum testosterone targets, application sites, titration, or reduction of symptoms. Patent 7,935,690 is primarily in this category because its independent claims are framed as treatment methods.

Delivery-device and application patents

Other patents cover metered-dose pumps, applicators, transfer-resistant systems, axillary delivery, nasal administration, and dose uniformity. These rights can remain relevant even if a formulation patent expires.

Manufacturing and process patents

Manufacturing patents may cover enhancer synthesis, gel compounding, mixing order, viscosity control, packaging, or filling. These rights are separate from the product-by-product analysis of the issued claims.

What generic entry risks exist?

A generic testosterone gel faces two separate questions:

Does the proposed formulation infringe the patent?
Does the patent create an FDA approval obstacle through Orange Book listing and Hatch-Waxman certification?

A product that uses a conventional testosterone gel vehicle but excludes the five macrocyclic enhancers may have a lower risk under this patent. A product that uses oxacyclohexadecan-2-one or one of the other listed enhancers at 8-25 wt.% presents substantially greater risk.

Generic launch scenarios

Launch design	Risk under Patent 7,935,690
Testosterone gel with listed macrocyclic enhancer at 8-25 wt.% and 40-80 wt.% ethanol	High claim-overlap risk
Testosterone gel with listed enhancer below the claimed concentration	Reduced literal infringement risk; equivalents analysis remains
Testosterone gel using a nonlisted penetration enhancer	Lower risk under the enhancer limitation
Low-ethanol or ethanol-free testosterone gel	Lower risk under the solvent limitation
Testosterone solution rather than gel	Potentially lower risk under dosage-form limitation
Patch, injection, nasal product, or oral product	Generally outside the core claim architecture
Product not labeled or promoted for male hypogonadism	May reduce method-of-use exposure, subject to actual use and inducement evidence

A formulation design-around should not rely on a single numerical change. The most robust strategy would normally alter the enhancer identity and dosage form or solvent system, while also documenting viscosity, pH, and composition through analytical testing.

Which companies are challenging the patent?

The claim text alone does not establish a Paragraph IV challenger, ANDA litigation, settlement, or license involving U.S. Patent 7,935,690. Those facts must be established from USPTO records, FDA Orange Book data, PACER or district-court dockets, and SEC disclosures.

Patent litigation involving other testosterone products should not be attributed to this patent without a docket-level match. Testosterone-gel litigation often involves multiple patents covering different products, formulations, applicators, and methods. A case involving AndroGel, Testim, Fortesta, Vogelxo, or another product does not automatically implicate Patent 7,935,690.

What licensing or settlement issues matter?

A license or settlement could affect commercial risk even if the patent appears expired, unlisted, or vulnerable. Relevant documents include:

Patent licenses covering macrocyclic enhancers;
Supply agreements for proprietary permeation enhancers;
ANDA settlement agreements;
Covenants not to sue;
Field-of-use restrictions;
Geographic limitations;
Royalty obligations;
Manufacturing restrictions; and
Agreements covering patent-family members rather than Patent 7,935,690 itself.

No license or settlement should be inferred from the claim language or from the existence of related testosterone products.

How does Patent 7,935,690 compare with broad testosterone-gel patents?

Patent 7,935,690 is narrower than a patent claiming testosterone gel generally but potentially stronger against a product that deliberately uses the claimed enhancer technology.

Issue	Patent 7,935,690	Broad testosterone-gel patent
Claim type	Treatment method with formulation limitations	Often composition, formulation, or use
Active ingredient	Six listed androgens	May focus on testosterone
Enhancer	Five specified macrocyclic compounds	May cover a different enhancer or broader vehicle
Ethanol	40-80 wt.% in claim 1	Depends on the patent
Viscosity	500-20,000 cps in claim 1	Depends on the patent
pH	3-9 in claim 1	Depends on the patent
Design-around potential	Relatively high through enhancer, dosage form, or solvent changes	Depends on claim breadth
Orange Book relevance	Product-specific	Product-specific
Main litigation issue	Complete formulation-plus-use overlap	Validity, infringement, and product matching

What geographic coverage does the patent provide?

U.S. Patent 7,935,690 provides rights only in the United States. It does not create protection in Canada, Europe, Japan, China, or other jurisdictions.

International protection would require separate national or regional patent family members. The commercial analysis should distinguish:

U.S. issued claims;
Foreign granted claims;
Pending foreign applications;
Abandoned applications;
Patent-term differences;
Supplementary protection certificates;
National-phase status; and
Local enforcement standards.

A U.S. design-around does not establish freedom to operate outside the United States.

What is the commercial impact of the patent?

The patent’s revenue exposure is linked to products that combine testosterone or another listed androgen with one of the five macrocyclic enhancers. It is not a direct barrier to the entire testosterone-replacement market.

The highest exposure would arise where:

The product is a topical gel;
The label treats male hypogonadism;
Testosterone is present at approximately 0.1-5 wt.%;
A listed enhancer is present at 8-25 wt.%;
Ethanol is present at 40-80 wt.%; and
The viscosity and pH fall within claim 1.

Products using injections, patches, nasal delivery, oral testosterone, or nonlisted enhancers occupy materially different risk positions.

Key Takeaways

U.S. Patent 7,935,690 is a formulation-specific method patent for transdermal androgen treatment.
Claim 1 requires all major elements, including a listed macrocyclic enhancer at 8-25 wt.% and ethanol at 40-80 wt.%.
Claims 2-16 narrow the patent through polyethylene glycol, viscosity, pH, solvent, glycerin, propylene glycol, and enhancer-specific limitations.
Conventional testosterone gel products do not automatically infringe.
The macrocyclic enhancer limitation is the principal technical boundary.
Solutions, patches, injections, nasal products, and oral products generally fall outside the core claim architecture.
Orange Book listing, Paragraph IV exposure, litigation, licensing, and settlement status cannot be established from the claim text alone.
U.S. rights do not extend automatically to foreign markets.
Patent-term and maintenance-fee records should control the current enforceability analysis.

FAQs

Does a 1% testosterone gel automatically infringe U.S. Patent 7,935,690?

No. The product must also contain a claimed macrocyclic enhancer, thickener, ethanol within the claimed range, and the other formulation and method limitations.

Is a testosterone gel using carbomer covered by this patent?

Carbomer may satisfy the broad thickening-agent limitation, but carbomer is not one of the claimed macrocyclic enhancers. The product would need a listed macrocyclic enhancer to satisfy claim 1 literally.

Can a testosterone solution avoid Patent 7,935,690?

Potentially. The claims require a topical gel. Whether a product is legally a solution, gel, lotion, or another dosage form depends on its formulation characteristics and claim construction.

Are claims 12 through 16 independent claims?

No. They are dependent claims and include every limitation of claim 1, while specifying one particular macrocyclic enhancer.

Does expiration of Patent 7,935,690 eliminate all testosterone-gel patent risk?

No. Other patents may cover the active ingredient, formulation, delivery device, method of use, manufacturing process, or an approved product’s labeling.

References

United States Patent and Trademark Office. (n.d.). U.S. Patent No. 7,935,690. USPTO Patent Center.
United States Code. (2023). 35 U.S.C. § 154: Contents and term of patents; provisional rights.
U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations: Orange Book. FDA.

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Argentina	039644	⤷ Start Trial
Argentina	087484	⤷ Start Trial
Austria	371456	⤷ Start Trial
Australia	2003228612	⤷ Start Trial
Brazil	0309390	⤷ Start Trial
Canada	2470200	⤷ Start Trial
China	102357098	⤷ Start Trial
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Summary for Patent: 7,935,690