Details for Patent: 7,608,610

Summary for Patent: 7,608,610

Title:	Pharmaceutical composition
Abstract:	A pharmaceutical composition comprising: (A) an androgen; (B) a cyclic enhancer of the type used in the compositions and methods claimed by U.S. Pat. No. 5,023,252 to Hsieh; and (C) a thickening agent; including, for example, a composition in which the cyclic enhancer is a macrocyclic ester or a macrocyclic ketone; the use of the composition to treat a condition, for example, male hypogonadism, in a patient by applying the composition to the membrane of the patient; and a method for making the composition.
Inventor(s):	Robert J. Gyurik
Assignee:	FCB I LLC
Application Number:	US12/364,413
Patent Litigation and PTAB cases:	See patent lawsuits and PTAB cases for patent 7,608,610
Patent Claim Types: see list of patent claims	Use; Composition; Delivery;

Scope and Claims Analysis of US Patent 7,608,610 (Testosterone Transdermal Gel with Macrocyclic Enhancers) and the U.S. Patent Landscape

US 7,608,610 is directed to a testosterone transdermal topical gel and a method of maintaining therapeutic serum testosterone in men with hypogonadism by applying a specific gel composition to skin. The core inventive concept is the combination of (i) a defined topical gel physicochemical profile (viscosity and pH), (ii) an ethanol-rich solvent system, and (iii) a macrocyclic enhancer selected from a short, enumerated ketone/enone/heterocycle group, optionally with polyethylene glycol and other polyols. The claim set is heavily parameterized by numeric ranges, which narrows literal scope but increases the number of design-around opportunities.

What is US Patent 7,608,610 protecting for testosterone transdermal gel in the U.S.?

US 7,608,610 protects a method for treating hypogonadism via transdermal delivery that hinges on a specific gel formulation window and expected pharmacokinetic performance after a unit dose.

Independent claim 1: what are the required claim elements?

Claim 1 recites a method comprising transdermal delivery to a male by applying a topical gel to skin. The composition must satisfy all of the following constraints:

1. Condition and outcome framing

   • Treating hypogonadism by maintaining a therapeutically effective concentration of testosterone in blood serum.
   • Delivery is assessed via transdermal application and maintaining serum testosterone level over time.

2. Topical gel physical parameters

   • Viscosity: about 500 to about 20,000 cP
   • pH: about 3 to about 9

3. Composition components and numeric ranges

   • Testosterone: about 0.1 to about 5 wt. %
   • Macrocyclic enhancer: about 0.5 to about 25 wt. %, selected from:
     • 3-methylcyclopentadecanone
     • 9-cycloheptadecen-1-one
     • cyclohexadecanone
     • cyclopentadecanone
     • oxacyclohexadecan-2-one
     • mixtures thereof
   • Thickening agent: about 0.1 to about 10 wt. %
   • Ethanol in solvent mixture: about 40 wt. % to about 80 wt. % (and solvents include that ethanol proportion)

These limitations mean the patent is not a broad “testosterone transdermal gel” patent. It is a targeted formulation and method patent that requires the macrocyclic enhancer class, plus defined gel rheology, pH, and ethanol loading.

How claims 2–3 narrow polyethylene glycol

• Claim 2 adds polyethylene glycol (PEG) to the composition.
• Claim 3 restricts PEG to about 0.001 to about 5 wt. %.

PEG is not part of claim 1, so adding PEG expands coverage only for formulations that still meet all claim 1 constraints.

How claim 4 adds a pharmacokinetic performance requirement

Claim 4 further limits claim 1 by requiring:

• The composition is maintained on skin long enough for delivery.
• Applied as a unit dose containing about 1 to about 300 mg testosterone.
• The resulting PK outcome is required:
  • AUC0–24 increase (circulating testosterone) of about 100 to about 35,000 ng·h/dL above the same 24-hour period without the dose.

This is a powerful limitation: even if a competitor matches the composition, it must also support the specified PK performance window for literal infringement under this claim.

Claims 5–7 lock in viscosity sub-ranges

• Claim 5: about 1,000 to about 9,000 cP
• Claim 6: about 2,000 to about 8,000 cP
• Claim 7: about 3,000 to about 7,000 cP

These are layered dependent claims. If a product’s viscosity is outside these windows but inside claim 1’s broad band, it could still infringe claim 1 but not the narrower dependent claims.

Claims 8–10 lock in pH and ethanol sub-ranges

• Claim 8: pH 4 to 8
• Claim 9: ethanol 50 wt. % to 75 wt. %
• Claim 10: ethanol 60 wt. % to 75 wt. %

Again, claim 1 is broad; the dependent claims narrow.

Claims 11–12 optionally add additional excipients

• Claim 11: further comprising propylene glycol (no numeric range provided here)
• Claim 12: further comprising glycerin (no numeric range provided here)

These optional excipients increase coverage for formulations that still match claim 1.

Claims 13–17 lock in specific macrocyclic enhancer embodiments

Claim 13–17 each specify one macrocyclic enhancer from claim 1’s list:

• 3-methylcyclopentadecanone
• 9-cycloheptadecen-1-one
• cyclohexadecanone
• cyclopentadecanone
• oxacyclohexadecan-2-one

This creates multiple “tracks” for enforcement: infringement can be argued under the specific enhancer compound used by the product.

What is the practical claim scope and where do design-arounds exist?

A. Macrocyclic enhancer substitution is the biggest lever

Claim 1 requires the enhancer to be one of the enumerated macrocyclic ketone/enone/heterocycle compounds. A product using:

• a different enhancer chemistry outside the enumerated list, or
• a structurally different macrocyclic enhancer not listed, is the clearest path to avoid literal claim 1.

B. Rheology and pH windows create additional literal non-infringement risk

Even with the same enhancer and ethanol system, competitors can engineer:

• viscosity outside the broad claim 1 range (500–20,000 cP), or
• pH outside 3–9. To avoid dependent claims, target outside the tighter windows (1,000–9,000 cP; 3,000–7,000 cP; pH 4–8; ethanol 60–75 wt.%).

C. Ethanol loading can be engineered

Claim 1 requires ethanol at 40–80 wt.%. Dependent claims require narrower ethanol bands (50–75 wt.%, then 60–75 wt.%). Shifting the formulation to ethanol below 50 wt.% or above 75 wt.% is a common design-around concept.

D. Pharmacokinetic (AUC) limitation can defeat “same formula” arguments

Claim 4 requires an AUC0–24 increase range and ties infringement to a measurable clinical/pharmacokinetic outcome. If a competitor formulates within the composition ranges but demonstrates a different magnitude of AUC increase outside 100–35,000 ng·h/dL (above no-dose baseline), claim 4 may not be met.

In litigation, this is typically where experts and comparative PK studies matter.

How does this patent compare with typical testosterone gel IP (AndroGel-style products) for coverage breadth?

Most testosterone gel portfolios in the U.S. historically cluster around:

• specific formulations (carbomer and solvent systems),
• specific dosing regimens and device/application methods,
• and sometimes enhancer or permeation-related excipients.

US 7,608,610 is distinct because it:

• explicitly claims a macrocyclic enhancer class by chemical identity,
• binds the formulation to quantified viscosity and pH bands,
• and includes a PK AUC outcome dependent claim.

That structure gives the patent estate both:

• strong chemistry-to-structure anchors (macrocyclic enhancer identity and amounts), and
• an outcome anchor (claim 4), which can help enforce against near-formula variants if they still achieve the claimed PK window.

What does US 7,608,610 imply about Orange Book status and FDA listings?

This requires an Orange Book mapping (listed drug, NDA, and listed patents). The information provided does not include:

• the NDA/BLA number,
• the listed drug name (e.g., AndroGel, Fortesta, Testim, generic equivalents),
• or the Orange Book patent listing number tied to 7,608,610.

Without that linkage, the Orange Book status cannot be determined from the claims alone.

What patent expiration and exclusivity timelines apply to US 7,608,610 in the U.S.?

The claims alone do not provide:

• the filing date,
• the priority date,
• or the patent term adjustment/extension.

Without those dates, expiration timing cannot be stated accurately for decision-making.

How strong is the patent estate around US 7,608,610 for enforcement risk?

Based on the claim language supplied, strength indicators are:

1) High specificity reduces “innocent overlap,” but improves enforceability against close copies

The enhancer is limited to named structures and included at specific wt.% ranges. This specificity can narrow the number of plausible products but can strengthen infringement arguments if a competitor uses the same enhancer chemistry.

2) Dependent claims add multiple “entry points”

There are multiple dependent layers (PEG; tighter viscosity; pH; ethanol; optional propylene glycol and glycerin; specific enhancer embodiments). If a competitor uses the enhancer and stays within composition ranges, there may be multiple dependent claims that fit, increasing leverage.

3) Claim 4’s AUC requirement can cut both ways

• It can narrow enforceable scope for claim 4 only.
• It can also provide a measurable target to attack formulations that achieve similar PK profiles.

From a litigation perspective, it increases evidentiary needs but can materially strengthen claim 4 if comparative PK data supports the window.

What generic entry risks exist for testosterone transdermal gels under this patent?

A generic entrant (or an authorized generic) faces risk if its formulation:

• uses one of the enumerated macrocyclic enhancers,
• matches the enhancer wt.% window (0.5–25%),
• uses ethanol at 40–80 wt.% (and potentially the narrower dependent windows),
• and has viscosity and pH in the required ranges.

If the generic differs by:

• using a different permeation enhancer mechanism,
• changing ethanol loading,
• moving viscosity and pH out of the defined windows,
• or failing the claim 4 AUC performance requirement for the unit-dose regimen, then literal infringement risk decreases.

What patent litigation or Paragraph IV challenges involve US 7,608,610?

No litigation docket, Paragraph IV filing information, settlement data, or FDA linkage is included in the prompt. A litigation landscape cannot be produced from claim language alone.

Which companies are most likely to be implicated by US 7,608,610?

Company identification depends on:

• which approved testosterone products use macrocyclic enhancer compounds matching the enumerated list,
• whether those products incorporate ethanol-rich solvent systems with the claimed viscosity and pH,
• and whether their excipient systems use the specified thickening agents in the claimed amount windows.

The prompt does not include product names, active ingredient sources, enhancer suppliers, or FDA application mappings, so company-level attribution cannot be made.

What formulations are protected: gel viscosity, pH, ethanol solvent system, and enhancer identity

Protected formulation “core” (claim 1)

• Testosterone: 0.1–5 wt.%
• Macrocyclic enhancer: 0.5–25 wt.% (enumerated identities)
• Thickening agent: 0.1–10 wt.%
• Ethanol: 40–80 wt.% in solvent mixture
• Viscosity: 500–20,000 cP
• pH: 3–9
• Form: topical gel, transdermal application to a male for hypogonadism

Protected “stacked” modifications

• PEG: 0.001–5 wt.% (claim 2–3)
• Unit dose containing 1–300 mg testosterone and producing AUC increase 100–35,000 ng·h/dL above no-dose (claim 4)
• Viscosity narrowed: 1,000–9,000 cP; 2,000–8,000 cP; 3,000–7,000 cP
• pH narrowed: 4–8
• Ethanol narrowed: 50–75 wt.% then 60–75 wt.%
• Optional propylene glycol and glycerin

Timeline framing: how claim narrowing affects infringement exposure during development and post-approval changes

A common commercial reality is that gel products can be reformulated within approved ranges. Under US 7,608,610:

• If a formulation is within claim 1 but outside a dependent parameter window (e.g., viscosity 250–400 cP or ethanol <50 wt.%), dependent claims may fall away while claim 1 remains.
• If a product switches macrocyclic enhancer to a non-enumerated chemistry, all dependent enhancer-embodiment claims (13–17) and claim 1 likely fail.
• If product developers alter ethanol content and pH to broader OTC gel targets, dependent claim narrowing can be avoided, but claim 1 still covers broad windows unless fully escaped.

Key Takeaways

• US 7,608,610 protects a testosterone transdermal topical gel method for hypogonadism anchored to a defined macrocyclic enhancer list, ethanol-rich solvent system, and specific viscosity and pH ranges.
• The strongest literal design-around levers are (i) using a non-enumerated enhancer, (ii) moving ethanol, pH, or viscosity outside claim windows, and (iii) for claim 4 specifically, avoiding the required unit-dose AUC0–24 increase range.
• The dependent claims create multiple enforcement hooks (PEG inclusion, narrower rheology bands, ethanol subranges, and specific enhancer identities), but they also provide clear routes to avoid narrower claims by formulation parameter shifts.

FAQs

1. Does US 7,608,610 cover any testosterone gel, or only enhancer-containing ethanol gels?
   It is limited to gels that include the specified macrocyclic enhancer identities at the claimed wt.% ranges plus an ethanol solvent mixture at the claimed wt.% levels, along with viscosity and pH constraints.

2. Is the AUC0–24 limitation only relevant to claim 4, or can it affect other claims?
   The AUC constraint is explicit in claim 4 as a dependent limitation. Independent scope (claim 1) is not defined by AUC in the provided claim text.

3. Can a reformulated product avoid claim 1 by adjusting viscosity only?
   Yes, if viscosity is moved outside claim 1’s 500–20,000 cP band. Keeping viscosity within claim 1 but outside dependent viscosity bands may avoid narrower dependent claims while leaving claim 1 exposure.

4. How do claims 13–17 change infringement analysis?
   They create separate dependent claim paths tied to the exact enhancer compound used. Products using an enumerated enhancer must still satisfy all other claim 1 elements.

5. Does adding PEG automatically infringe?
   PEG inclusion alone does not create infringement. PEG must be included within the claim 3 wt.% range (if relying on claims 2–3) and the base composition must meet claim 1 constraints.

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References

1. US Patent 7,608,610 (claims provided in prompt).

Drugs Protected by US Patent 7,608,610

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Patented / Exclusive Use	Submissiondate

International Family Members for US Patent 7,608,610

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Argentina	039644
Argentina	087484
Austria	371456
Australia	2003228612