United States Patent 10,383,820: Colchicine Oral Solution Scope, Claims, Exclusivity and Generic Risk

U.S. Patent No. 10,383,820 protects specific methods of treating colchicine-sensitive disorders, principally gout, with a stabilized oral colchicine liquid. The patent does not broadly claim colchicine, colchicine tablets, or every liquid colchicine product. Its strongest coverage is directed to an oral solution containing defined ranges of colchicine, citric acid, dibasic sodium phosphate heptahydrate, a thickening agent, preservative, glycols and water, together with stability requirements.

The patent's commercially important concentration is 0.12 mg/mL. The likely patent-term expiration date is January 13, 2035, based on the underlying January 13, 2015 priority date and the standard 20-year patent term. The patent is associated with Gloperba, an oral colchicine solution marketed for acute and chronic gout treatment. The Orange Book and USPTO records should control any final diligence determination concerning listed patents, patent-term adjustment and current litigation.

What does U.S. Patent 10,383,820 cover?

The patent covers a treatment method requiring all of the following elements:

A human subject has a colchicine-sensitive disorder.
The subject receives colchicine orally.
The colchicine is administered as a liquid solution.
The solution contains colchicine at 0.01-1.0 mg/mL.
The solution contains 0.1-0.3% w/v anhydrous citric acid.
The solution contains 0.8-1.6% w/v dibasic sodium phosphate heptahydrate.
The solution contains 0.1-0.2% w/v of a thickening agent.
The solution contains a preservative, glycols and water.
The solution is stable for at least one month under refrigerated and ambient conditions.
The solution is administered in an effective amount to treat the disorder.

Claim 1 identifies nine disorders:

Gout
Familial Mediterranean fever
Pericarditis
Behçet's disease
Atrial fibrillation
Amyloidosis
Calcium pyrophosphate deposition disease, commonly called pseudogout
Cirrhosis of the liver
Sarcoid arthritis

The claim is a method-of-treatment claim combined with a formulation limitation. A competitor would generally need to practice the claimed treatment method, not merely manufacture or sell a liquid containing colchicine, to directly infringe claim 1.

What formulation parameters are protected?

Formulation attribute	Claim limitation
Colchicine concentration	0.01-1.0 mg/mL
Anhydrous citric acid	0.1-0.3% w/v
Dibasic sodium phosphate heptahydrate	0.8-1.6% w/v
Thickening agent	0.1-0.2% w/v
Preservative	Required
Glycols	Required
Water	Required
Stability	At least one month at refrigerated and ambient conditions
Commercially specified concentration	0.12 mg/mL in claims 8 and 10

The ranges are cumulative. A liquid product that contains colchicine at 0.12 mg/mL but falls outside the citric-acid or phosphate ranges may avoid literal infringement of the independent claims, subject to the doctrine of equivalents and the precise product composition.

How do the individual claims differ?

Claim 1: Broadest independent method claim

Claim 1 covers oral administration of the specified solution for any one of the nine listed disorders. It is broader than claim 9 as to disease scope because it includes disorders other than gout. It is narrower than a general liquid-colchicine claim because it requires the specified excipient system and stability profile.

The unusual inclusion of atrial fibrillation, cirrhosis and other conditions expands the disease list, but it does not eliminate the need to prove that the accused product satisfies the formulation and stability limitations.

Claims 2-7: Quality and product-characterization limitations

These claims add technical characteristics that may be important in product testing and litigation.

Claim	Added limitation	Enforcement relevance
2	Propylene glycol, glycerin, benzyl alcohol, xanthan gum, sucralose, dye, flavoring or taste-enhancing agent	Makes the claim more formulation-specific
3	Stable pH	May require defined testing and interpretation of "stable"
4	Viscosity of 40-800 cP	Provides a measurable physical limitation
5	Less than 5% total impurities	Creates an analytical quality threshold
6	Less than 0.5% degradants	Creates a tighter impurity limitation
7	Degradants include beta-lumicolchicine, gamma-lumicolchicine and/or colchiceine	Identifies specific colchicine degradation products

Claim 2 is drafted broadly because it uses "one or more" listed ingredients. A formulation does not need every listed excipient to meet the claim.

Claims 5-7 may present proof issues. Total impurities and degradants depend on analytical methods, reference standards, detection limits, sampling conditions and the time point used for testing. A patent dispute would likely focus on the specification's analytical methods and whether the claim terms provide an objective testing protocol.

Claim 8: 0.12 mg/mL embodiment

Claim 8 narrows claim 1 to a solution containing 0.12 mg/mL colchicine. This concentration corresponds to the commercially relevant Gloperba presentation.

The claim remains subject to all limitations of claim 1. A 0.12 mg/mL product that lacks the required excipient ranges or stability characteristics does not automatically fall within claim 8.

Claim 9: Independent gout method claim

Claim 9 is independently directed to treating gout. It removes the nine-disorder list found in claim 1 and therefore focuses on the principal commercial indication.

Claim 9 still requires:

Oral administration to a human subject
An effective amount
A liquid colchicine solution
The claimed concentration and excipient ranges
At least one month of stability at refrigerated and ambient conditions

Because gout is a common indication for colchicine, claim 9 is likely the principal enforcement claim against a competing gout-oriented oral solution.

Claim 10: 0.12 mg/mL gout claim

Claim 10 narrows claim 9 to the 0.12 mg/mL formulation. It is likely the closest claim to the marketed product if the commercial formulation uses that concentration.

What is the patent's legal scope?

The patent has four important legal characteristics.

It is primarily a method patent

The claims require administering the liquid to a human. They do not expressly claim the liquid composition as a standalone article. This distinction affects:

Direct infringement analysis
ANDA litigation strategy
Inducement theories
Label-based infringement
The relevance of a proposed generic's prescribing information

A generic applicant could argue that its product does not meet the method claims, but the FDA-approved label may create inducement exposure if it instructs use for gout or another covered disorder.

It requires a combination of excipients

The formulation is not defined by colchicine concentration alone. The citric acid, phosphate, thickener, preservative, glycols and water limitations create a multi-parameter claim.

A competing oral solution may reduce risk by changing one or more of:

Buffer system
Acidulant
Thickener
Preservative
Glycol
Colchicine concentration
pH
Viscosity
Stability profile

A design-around must account for possible equivalents. Minor changes in concentration may not eliminate risk if the accused formulation performs substantially the same function in substantially the same way.

Stability is a material claim limitation

The solution must remain stable for at least one month at both refrigerated and ambient conditions. Stability may involve chemical potency, impurity formation, physical appearance, pH or another metric disclosed in the patent specification.

This limitation can create a factual dispute. The patent claims do not, in the text provided, define the precise acceptance criteria for "stable." The specification, prosecution history and claim-construction record would be important in litigation.

The claims have nested fallback positions

The claim structure gives the patent holder several infringement theories:

Broad disease coverage under claim 1
Gout-focused coverage under claim 9
Excipient-specific coverage under claim 2
Viscosity coverage under claim 4
Impurity coverage under claims 5-7
0.12 mg/mL coverage under claims 8 and 10

A challenger that defeats one limitation may still face a narrower claim if its product matches the 0.12 mg/mL concentration or the viscosity and impurity specifications.

When does U.S. Patent 10,383,820 expire?

The projected expiration date is January 13, 2035, assuming the relevant earliest nonprovisional priority date is January 13, 2015 and no adjustment or terminal disclaimer changes the calculation.

Event	Date or status
Earliest reported priority date	January 13, 2015
U.S. patent grant	August 20, 2019
Standard 20-year term calculation	January 13, 2035
Patent-term adjustment	Must be verified in the USPTO patent record
Patent-term extension	No confirmed extension identified
Pediatric exclusivity	No confirmed pediatric extension identified
Projected ordinary expiration	January 13, 2035

Patent expiration is separate from FDA regulatory exclusivity. Colchicine is an established active ingredient, so the commercial protection is primarily patent-based rather than based on new chemical entity exclusivity.

A patent-term adjustment could move the effective expiration date later. A terminal disclaimer could limit the term. The USPTO front page and Orange Book patent listing are controlling for transaction and litigation diligence. [1, 2]

What is the Orange Book status of the patent?

Gloperba is the product most directly associated with this patent. Gloperba is an oral colchicine solution approved by the FDA for the treatment of gout flares in adults and for prophylaxis of gout flares in adults. The product is distinct from:

Colcrys colchicine tablets
Generic colchicine tablets
Mitigare colchicine capsules
Other solid oral colchicine products

The patent's commercial relevance depends on whether it is listed for the applicable Gloperba NDA and whether the Orange Book identifies the patent as covering the drug substance, drug product or method of use. A method patent normally appears with a use code. An ANDA applicant may address the listing through a Paragraph IV certification, a Paragraph III certification or a section viii statement, depending on the proposed labeling and the listing details.

Regulatory issue	Assessment
Reference product	Gloperba oral colchicine solution
Active ingredient	Colchicine
Dosage form	Oral solution
FDA pathway	NDA
Main protected use	Gout treatment and prophylaxis-related use
Orange Book relevance	Determines whether an ANDA certification is required
NCE exclusivity	Not expected for colchicine
Patent-based barrier	Potentially extends to 2035
Solid oral colchicine products	Generally outside the liquid-solution formulation limitations

The Orange Book listing should be reviewed by NDA number and use code, rather than by patent number alone. [2, 3]

What generic entry risks exist for Gloperba?

A generic oral solution faces greater patent exposure than a generic colchicine tablet because it may need to match the reference product's concentration, excipient profile, stability and labeling.

Likely ANDA certification options

Certification	Commercial consequence
Paragraph III	Applicant accepts the patent and delays launch until expiry
Paragraph IV	Applicant alleges that the patent is invalid, unenforceable or not infringed
Section viii statement	Applicant omits a patented method from labeling, if legally available
No certification for unlisted patent	Possible only if the patent is not subject to Orange Book certification requirements

A Paragraph IV notice to the patent owner and NDA holder can trigger a patent action within 45 days. Filing suit generally creates a 30-month stay of ANDA approval, subject to statutory exceptions and court events. [4]

Generic launch scenarios

Launch after patent expiration

This is the lowest-risk scenario. It avoids a patent challenge but delays market entry until approximately 2035, subject to patent-term adjustment.

Paragraph IV launch after litigation

A generic applicant may challenge the patent before expiration. The outcome would depend on the proposed formulation, labeling, claim construction, prosecution history and evidence on obviousness and written description.

Section viii launch

A generic may attempt to omit covered uses from its labeling. This strategy is more difficult if the product's label necessarily instructs treatment or prophylaxis of gout using a formulation that falls within the claims.

Non-infringing formulation launch

A competitor could develop a different oral liquid with a different buffer, thickener, preservative system or concentration. This strategy requires formulation work and a careful equivalents analysis.

How strong is the patent estate?

The patent has moderate commercial strength for the specific liquid formulation and weaker reach against colchicine products generally.

Strength factor	Assessment
Product specificity	Strong; the claims map to a defined liquid formulation
Concentration coverage	Broad in claims 1 and 9; narrower 0.12 mg/mL claims provide product-specific fallback
Disease coverage	Broad in claim 1, with gout separately protected in claim 9
Tablet protection	Minimal; tablets generally do not satisfy the liquid-solution limitation
Capsule protection	Minimal for the same reason
Excipient design-around potential	Material
Stability limitation	Commercially relevant but potentially difficult to prove
Method-of-use enforcement	Depends on labeling and actual administration
Prior-art exposure	Significant because colchicine is an old drug and liquid pharmaceutical formulations are well developed
Litigation leverage	Highest against a directly substitutable 0.12 mg/mL oral solution

The principal validity risks are obviousness, anticipation, written description and indefiniteness.

Obviousness and anticipation risks

Colchicine has been used for decades. A challenger could combine prior art relating to:

Colchicine treatment of gout
Oral liquid dosage forms
Citric acid and phosphate buffering
Preservatives and glycols
Thickened pharmaceutical solutions
Taste-masking systems
Stability testing of colchicine formulations

The patent holder's response would likely rely on the specific combination of excipient ranges, stability performance, impurity control, viscosity and the claimed concentration.

Written-description and enablement issues

The broad range of disorders in claim 1 may receive scrutiny if the specification does not adequately support treatment of every listed disorder with the claimed liquid formulation. The claim also covers a broad colchicine range of 0.01-1.0 mg/mL while imposing multiple excipient and stability requirements.

Indefiniteness issues

Potentially contestable terms include:

"Effective amount"
"Stable pH"
"Stable for at least one month"
"Stability"
"Total impurities"
"Degradants"

Their enforceability will depend on the specification's definitions, testing procedures and examples.

What manufacturing and intellectual-property barriers remain?

The patent is only one part of the entry barrier. A competing oral solution must also solve technical and regulatory problems.

Manufacturing barriers

Colchicine has a narrow therapeutic index. Manufacturing controls must address:

Accurate low-dose content uniformity
Homogeneous dispersion
Chemical degradation
Light and temperature sensitivity
Microbial preservation
Viscosity control
Container-closure compatibility
Dose-measuring-device accuracy
Taste acceptability

A change in buffer or preservative can alter degradation, palatability and product shelf life. A formulation that avoids the patent may require new stability studies and bridging work.

Regulatory barriers

An ANDA applicant must demonstrate pharmaceutical equivalence and bioequivalence or otherwise satisfy the applicable FDA requirements for an oral solution. The applicant must also address:

Reference-listed-drug formulation differences
Inactive-ingredient justification
Microbial limits
Stability data
Labeling carve-outs
Drug-device compatibility if a dosing syringe is supplied

A 505(b)(2) applicant may pursue a different regulatory strategy, particularly if the formulation or dosing presentation differs materially from the reference product.

How does Gloperba compare with other colchicine products?

Product	Dosage form	Primary commercial distinction	Exposure to Patent 10,383,820
Gloperba	Oral solution	Liquid colchicine, commonly associated with 0.12 mg/mL concentration	Highest
Colcrys	Tablet	Solid oral colchicine	Generally low for this patent
Generic colchicine	Tablet	Lower-cost solid oral product	Generally low for this patent
Mitigare	Capsule	Solid oral colchicine capsule	Generally low for this patent
New liquid colchicine entrant	Oral solution	Direct substitute for Gloperba	Material, depending on formulation and label

The patent therefore protects a differentiated dosage form rather than the entire colchicine market. Tablet and capsule competition can erode the liquid product's pricing without directly practicing the claimed liquid-solution method.

Which companies are most exposed to this patent?

The highest-risk parties are:

A generic applicant developing a 0.12 mg/mL colchicine oral solution.
A 505(b)(2) sponsor relying on Gloperba's clinical and formulation profile.
A contract manufacturer producing the same or substantially similar formulation.
A distributor or marketer whose labeling recommends covered gout treatment.
A licensee commercializing an equivalent oral colchicine solution.

Companies selling colchicine tablets or capsules face substantially lower risk under the claims provided because the dosage form limitation is liquid solution.

What litigation and settlement issues should be monitored?

A Paragraph IV dispute would likely center on:

Whether the proposed product contains the claimed excipient ranges
Whether the product is stable for the claimed period
Whether the proposed label induces treatment of gout or another covered disorder
Whether the claimed formulation would have been obvious
Whether the patent adequately supports the full disease list
Whether the patent's stability and impurity terms are definite
Whether the generic's formulation differs enough to avoid literal infringement

A settlement could provide an agreed launch date, a license, a supply arrangement or a formulation restriction. No settlement terms should be assumed without a filed consent judgment, court order, SEC disclosure or other primary record.

Key Takeaways

U.S. Patent 10,383,820 is a formulation-linked method patent for oral liquid colchicine.
Its strongest commercial claims are claims 9 and 10, which target gout treatment and a 0.12 mg/mL solution.
The patent requires a defined excipient system, including citric acid, dibasic sodium phosphate heptahydrate, a thickening agent, preservative, glycols and water.
Claims 5-7 add impurity and degradation-product limitations that may require detailed analytical evidence.
Tablets and capsules are generally outside the provided claim scope.
The projected ordinary expiration date is January 13, 2035, subject to USPTO patent-term adjustment and Orange Book confirmation.
A generic liquid solution would face the greatest risk through a Paragraph IV challenge or an attempt to design around the excipient and stability limitations.
The patent estate has meaningful commercial value for a direct Gloperba substitute but does not block the broader colchicine market.

FAQs

Does Patent 10,383,820 cover all colchicine products?

No. The claims provided focus on an orally administered liquid colchicine solution with specified excipient ranges and stability characteristics. Colchicine tablets and capsules generally do not satisfy the liquid-solution limitation.

Can a competitor avoid the patent by using a concentration other than 0.12 mg/mL?

Possibly, but not automatically. Claims 1 and 9 cover colchicine concentrations from 0.01-1.0 mg/mL. A concentration outside 0.12 mg/mL may avoid claims 8 and 10 while remaining within claims 1 or 9.

Is a liquid colchicine product infringing if it is sold but not administered?

Direct infringement of the asserted method claims generally requires performance of the claimed administration method. Sale and labeling conduct may create separate inducement or contributory-infringement issues.

Does the patent cover treatment of familial Mediterranean fever?

Claim 1 expressly includes familial Mediterranean fever. A product and label must still satisfy every formulation, administration and stability limitation in the claim.

Can a generic omit gout treatment from its label to avoid the patent?

A section viii strategy may be available in some circumstances, but its viability depends on the Orange Book use code, the proposed label and whether the remaining labeling would still instruct a patented use. A product intended to substitute for Gloperba would face particular scrutiny.

References

United States Patent and Trademark Office. (2019). U.S. Patent No. 10,383,820, liquid colchicine formulations and methods of use.
U.S. Food and Drug Administration. (n.d.). Approved drug products with therapeutic equivalence evaluations: Orange Book.
U.S. Food and Drug Administration. (2019). Gloperba (colchicine) oral solution prescribing information.
35 U.S.C. § 271(e); 21 U.S.C. § 355(j).

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Patented / Exclusive Use	Submissiondate
Scilex Pharms	GLOPERBA	colchicine	SOLUTION;ORAL	210942-001	Jan 30, 2019		RX	Yes	Yes	10,383,820	⤷ Start Trial	Y			A METHOD OF PROPHYLACTIC TREATMENT OF GOUT FLARES IN ADULTS COMPRISES ADMINISTERING TO A PATIENT A LIQUID COLCHICINE ORAL SOLUTION	⤷ 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
World Intellectual Property Organization (WIPO)	2019126579	⤷ Start Trial
>Country	>Patent Number	>Estimated Expiration	>Supplementary Protection Certificate	>SPC Country	>SPC Expiration

Summary for Patent: 10,383,820