The claims of U.S. Patent No. 8,101,593 protect a narrow injectable formulation of deoxycholate, defined by concentration and alkaline pH. The core limitation is an aqueous formulation containing approximately 0.5% to 1.5% w/v deoxycholate at pH 8.0 to 8.5. Claim 2 adds subcutaneous administration, while claim 3 limits the excipient or carrier to water, a buffer, or a preservative. The patent is associated with the deoxycholic acid product Kybella and has an Orange Book-listed expiration date commonly reported as August 7, 2027.[1,2]

U.S. Patent 8,101,593 Deoxycholate Formulation Patent Scope and Landscape

What does U.S. Patent 8,101,593 protect?

U.S. Patent 8,101,593 protects a formulation combination rather than deoxycholic acid as a chemical entity. A product must satisfy the principal limitations below to fall within independent claim 1:

Claim element	Scope
Dosage form	Aqueous pharmaceutical formulation
Active ingredient	Deoxycholate
Concentration	About 0.5% to about 1.5% w/v
pH	About 8.0 to about 8.5
Additional ingredients	At least one pharmaceutically acceptable excipient and/or carrier
Administration route in dependent claim 2	Suitable for subcutaneous injection
Specific excipients in claim 3	Water, buffer, preservative, or combinations of those categories

The patent does not claim every deoxycholate formulation. It requires the concentration and pH limitations to occur together in an aqueous pharmaceutical preparation.

The use of the term “consisting of” in claim 1 is significant. It generally indicates a closed transitional phrase, limiting the claimed formulation to the recited formulation components and materials that do not materially alter the claimed invention. Courts assess the phrase in the context of the specification and claim structure. A formulation containing additional active ingredients, substantial stabilizers, surfactants, salts, or other functional components could create claim-construction and infringement issues.

How should the claims of U.S. 8,101,593 be construed?

Claim 1: core formulation claim

Claim 1 has four commercially important limitations:

The formulation must be aqueous.
The active must be deoxycholate.
The deoxycholate concentration must be approximately 0.5% to 1.5% w/v.
The pH must be approximately 8.0 to 8.5.

The concentration range is broad enough to cover common clinical formulations around 1% w/v. The pH range is materially narrower. A formulation at pH 7.9 or 8.6 would fall outside the literal numerical range, subject to the meaning of “about,” specification support, prosecution history, and possible application of the doctrine of equivalents.

The claim does not expressly require the formulation to contain only water and deoxycholate. It requires at least one pharmaceutically acceptable excipient and/or carrier. Claim 3 identifies water, a buffer, and a preservative as examples of the permitted excipient or carrier category.

Claim 2: subcutaneous-use limitation

Claim 2 narrows claim 1 to an aqueous formulation suitable for subcutaneous injection. It does not expressly require a particular needle, injection volume, injection site, dosing schedule, concentration per dose, or treatment indication.

A product could satisfy claim 1 without being labeled for subcutaneous administration. A product designed and labeled for subcutaneous administration would face the additional limitation in claim 2 if it also meets the concentration and pH requirements.

Claim 3: excipient and carrier limitation

Claim 3 depends on claim 1 or claim 2 and identifies the excipient or carrier as water, a buffer, or a preservative. The practical effect is to provide narrower claims directed to conventional injectable formulation components.

The wording does not require all three categories. “Selected from the group consisting of water, a buffer, and a preservative” generally permits one or more listed categories, subject to the specification and standard rules governing Markush claim interpretation.

What products are most likely covered by U.S. Patent 8,101,593?

The commercial product most closely associated with the patent is Kybella, an injectable deoxycholic acid product marketed by Kythera Biopharmaceuticals and later controlled by Allergan, now part of AbbVie. The FDA-approved product contains 10 mg/mL deoxycholic acid, equivalent to approximately 1% w/v, in an aqueous formulation with alkaline pH. Kybella is administered by subcutaneous injection for reduction of moderate-to-severe convexity or fullness associated with submental fat in adults.[3]

Product characteristic	Kybella-related profile	Relevance to claim 593
Active	Deoxycholic acid/deoxycholate	Satisfies active-ingredient subject matter
Concentration	10 mg/mL, approximately 1% w/v	Within the claimed 0.5% to 1.5% range
Dosage form	Aqueous injectable solution	Within claim 1
Route	Subcutaneous injection	Within claim 2
pH	Alkaline formulation within the claimed range, according to the patent and product disclosure	Potentially within claim 1
Indication	Submental fat in adults	Not expressly required by the claims

The claims are formulation claims. They do not require the use of the product for submental fat, facial contouring, obesity, cellulite, or another particular indication unless a separate claim in the patent or another patent imposes that restriction.

When does U.S. Patent 8,101,593 expire?

The commonly reported Orange Book expiration date for U.S. Patent 8,101,593 is August 7, 2027.[1,2] The patent issued January 24, 2012, from an application associated with the deoxycholate formulation program.[4]

Event	Date or status
U.S. patent application	Filed before issuance in the deoxycholate formulation family
Patent issued	January 24, 2012
Patent number	U.S. 8,101,593
FDA product association	Kybella
Commonly reported expiration	August 7, 2027
Patent status through expiration	Relevant formulation claims remain commercially significant unless invalidated, disclaimed, or otherwise limited

The final enforceable term must be determined from the patent file, maintenance-fee record, terminal-disclaimer information, and any applicable patent-term adjustment. The Orange Book date is the operative commercial reference for listed-drug competition analysis.

What is the Orange Book status of U.S. 8,101,593?

U.S. Patent 8,101,593 has been identified as an Orange Book-listed patent associated with Kybella. An Orange Book listing gives the NDA holder the opportunity to assert the patent against an ANDA applicant that makes a Paragraph IV certification.[1]

An Orange Book listing does not establish that every claim is valid, infringed, or enforceable. It identifies a patent that the sponsor considers relevant to the approved drug and its labeling.

The commercial importance of the listing is high because the claims are directed to the formulation used by the reference product, not merely to an optional manufacturing process. A generic applicant seeking approval for the same concentration, pH range, and subcutaneous injectable format would face a direct patent-risk assessment.

What Paragraph IV challenges could affect Kybella?

A generic applicant could submit an ANDA with a Paragraph IV certification alleging that U.S. Patent 8,101,593 is invalid, unenforceable, or not infringed.[5] The most likely design and litigation issues would involve:

Whether the proposed concentration falls within 0.5% to 1.5% w/v.
Whether the proposed pH falls within 8.0 to 8.5, including the meaning of “about.”
Whether the proposed formulation is aqueous.
Whether the active ingredient qualifies as deoxycholate.
Whether the formulation contains additional ingredients inconsistent with “consisting of.”
Whether the formulation is suitable for subcutaneous injection.
Whether the patent claims are anticipated or obvious based on earlier injectable bile-acid formulations.
Whether the patent adequately supports the full concentration and pH ranges under written-description and enablement standards.

A formulation outside both the literal concentration and pH ranges may reduce literal infringement risk. A design-around that changes only one parameter could still require analysis under the doctrine of equivalents and prosecution-history estoppel.

What other patents protect Kybella and deoxycholate formulations?

The 593 patent should be evaluated as one component of a broader Kybella patent estate. Public FDA and patent records identify additional U.S. patents associated with Kybella, including U.S. Patent Nos. 8,337,856 and 9,415,063, along with later patents reported in connection with the product.[1,6]

The related estate may include claims directed to:

Deoxycholic acid treatment methods.
Injection techniques and treatment regimens.
Use for submental fat or other localized adipose tissue.
Formulation characteristics.
Manufacturing and product-quality controls.
Additional dosage or administration parameters.

A competitor cannot rely solely on avoiding U.S. 8,101,593. It must screen the full Orange Book listing, patent-family continuations, terminal disclaimers, and method-of-use claims.

Formulation patents versus method-of-use patents

The 593 claims are formulation claims. Their infringement analysis focuses on the composition supplied or administered.

Method-of-use patents impose a different risk. A generic applicant may attempt to carve out a patented indication through a “section viii” statement and a restricted label. That strategy does not avoid a formulation patent if the generic product itself falls within the formulation claims.

This distinction matters for Kybella because a label carve-out may address a method-of-use claim but cannot remove an infringing concentration, pH, or dosage-form limitation from the product.

How strong is the patent estate for U.S. 8,101,593?

The 593 patent has moderate-to-strong commercial relevance because its principal limitations track the known Kybella formulation. Its strength is greatest against a copycat product using approximately 1% deoxycholate in an aqueous formulation at alkaline pH.

Strength factor	Assessment
Product alignment	Strong if the proposed product matches Kybella’s concentration and pH
Claim breadth	Moderate; the claims are limited by concentration, pH, aqueous form, and excipient language
Design-around potential	Moderate; a competitor may alter concentration, pH, excipient system, or route
Prior-art exposure	Requires review of injectable deoxycholate and bile-acid formulation disclosures
Regulatory leverage	Significant because the patent is associated with an approved NDA
Litigation leverage	Strongest before the August 2027 expiration date
Post-expiration value	Limited for the formulation claims, although other unexpired patents may remain relevant

The “about” language increases practical uncertainty around the edges of the numerical ranges. The patent holder would likely focus on products close to 1% w/v and pH 8.0 to 8.5. A product at 0.5% or 1.5% may present a stronger literal-infringement question than a product materially outside the claimed range.

What generic launch scenarios exist?

Launch before August 2027

A pre-expiration launch would likely require one of the following:

A successful Paragraph IV challenge.
A judicial finding of non-infringement.
A finding that the patent is invalid or unenforceable.
A license or settlement allowing an earlier launch.
A formulation design-around that avoids the asserted claims and any related patents.

Launch after August 2027

After the reported expiration of the 593 patent, a generic product may still face other listed or unlisted patent rights, regulatory exclusivity issues, labeling restrictions, and manufacturing barriers. The primary formulation patent would no longer block a product solely because it uses the claimed 0.5% to 1.5% concentration and pH 8.0 to 8.5 range, assuming no surviving patent or other legal restriction applies.

Does Kybella have biosimilar risk?

No conventional biosimilar pathway applies. Kybella is a chemically synthesized small-molecule drug, not a biologic regulated through the Public Health Service Act section 351(k) biosimilar pathway.[7]

Competitive entry would ordinarily proceed through an ANDA for a generic version, subject to pharmaceutical-equivalence, bioequivalence, labeling, patent-certification, and exclusivity requirements. The relevant competitor set therefore includes generic injectable manufacturers, specialty pharmaceutical companies, and companies developing non-deoxycholate alternatives for submental fat.

What regulatory exclusivity protected Kybella?

The FDA approved Kybella on April 29, 2015, for adults with moderate-to-severe convexity or fullness associated with submental fat.[3] The product received orphan-drug designation for the approved use. Orphan-drug exclusivity generally lasts seven years from approval under the Orphan Drug Act, subject to statutory exceptions.[8]

The seven-year orphan period would have ended in 2022. That exclusivity period does not extend the patent term and does not prevent all competing products in every indication. The principal remaining barrier has been patent protection and the requirements for obtaining approval of a competing injectable product.

What licensing and ownership issues affect the patent landscape?

Kythera developed Kybella and was acquired by Allergan in 2015. AbbVie acquired Allergan in 2020, placing the Kybella commercial and intellectual-property portfolio within AbbVie.[9,10]

The ownership chain matters for:

Patent enforcement.
ANDA litigation.
Licensing authority.
Settlement negotiations.
Assignment and maintenance records.
Global prosecution and continuation strategy.

A party evaluating freedom to operate should review USPTO assignment records and the current NDA holder information rather than relying only on the original patent assignee.

How does U.S. 8,101,593 compare with competing deoxycholate strategies?

Strategy	Exposure to U.S. 8,101,593	Key issue
Copycat 1% aqueous deoxycholate at pH 8.0 to 8.5	High	Direct overlap with claim 1
Same formulation for subcutaneous injection	Higher	Adds claim 2 overlap
Same formulation using water, buffer, or preservative	Highest	Adds claim 3 overlap
Concentration below 0.5% or above 1.5%	Reduced	Requires analysis of “about” and equivalents
pH materially below 8.0 or above 8.5	Reduced	Same range and equivalents issues
Non-aqueous formulation	Reduced for literal claim 1 infringement	May face other patents and regulatory issues
Different active ingredient	Outside these claims	Does not address other Kybella-related rights
Topical or oral deoxycholate product	Outside claim 2	Claim 1 may still require analysis if aqueous and within range

Key Takeaways

U.S. Patent 8,101,593 is a narrow but commercially relevant formulation patent.
Its core scope is an aqueous deoxycholate formulation at approximately 0.5% to 1.5% w/v and pH 8.0 to 8.5.
Kybella’s approximately 1% injectable deoxycholic acid formulation is closely aligned with the claim limitations.
Claim 2 adds suitability for subcutaneous injection; claim 3 narrows the excipient and carrier categories.
The commonly reported Orange Book expiration date is August 7, 2027.
Kybella is subject to generic, not biosimilar, competition.
A Paragraph IV challenge would likely focus on claim construction, prior art, obviousness, written description, enablement, and formulation design-around.
A full launch analysis must include the broader Kybella patent estate, not only U.S. 8,101,593.
Kythera’s Kybella rights moved through Allergan to AbbVie.
Orphan-drug exclusivity ended in 2022 and does not replace the patent-based analysis.

FAQs

Can a generic avoid U.S. 8,101,593 by changing only the pH?

Possibly, but the result depends on how far the pH moves outside 8.0 to 8.5, the meaning of “about,” prosecution history, and the doctrine of equivalents. A minor pH adjustment may not eliminate all infringement risk.

Does U.S. 8,101,593 claim deoxycholic acid itself?

No. The claims are directed to an aqueous pharmaceutical formulation containing deoxycholate within specified concentration and pH ranges. They do not claim the deoxycholic acid molecule as a standalone chemical compound.

Does a section viii label carve-out avoid this patent?

Generally no. A section viii carve-out may address a patented method of use, but it does not remove a formulation claim that is infringed by the composition itself.

Is a 10 mg/mL deoxycholic acid product likely to raise claim 1 issues?

Yes. Ten milligrams per milliliter is approximately 1% w/v, which falls within the claimed 0.5% to 1.5% range. The pH and other formulation elements must also be evaluated.

Can a company launch a competing deoxycholate product after 2027 without further analysis?

No. Expiration of U.S. 8,101,593 removes one formulation patent, but other Kybella patents, continuation patents, method-of-use claims, regulatory requirements, and manufacturing rights may remain relevant.

References

U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations: Orange Book.
United States Patent and Trademark Office. (2012). U.S. Patent No. 8,101,593, deoxycholate formulation claims.
U.S. Food and Drug Administration. (2015). Kybella prescribing information and approval announcement.
United States Patent and Trademark Office. (2012). Patent Center record for U.S. Patent No. 8,101,593.
U.S. Food and Drug Administration. (n.d.). ANDA submissions: Patent certifications and suitability petitions.
U.S. Food and Drug Administration. (2024). Orange Book patent listing information for Kybella.
U.S. Food and Drug Administration. (2024). Biosimilar and interchangeable biosimilar products.
Orphan Drug Act, 21 U.S.C. § 360cc.
Allergan plc. (2015). Annual report and Kythera acquisition materials.
AbbVie Inc. (2020). Annual report following acquisition of Allergan plc.

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	KYBELLA	deoxycholic acid	SOLUTION;SUBCUTANEOUS	206333-001	Apr 29, 2015	AP	RX	Yes	Yes	8,101,593	⤷ 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

Details for Patent: 8,101,593

Which drugs does patent 8,101,593 protect, and when does it expire?

Summary for Patent: 8,101,593