Details for Patent: 10,105,324

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Which drugs does patent 10,105,324 protect, and when does it expire?

Patent 10,105,324 protects OBREDON and is included in one NDA.

Summary for Patent: 10,105,324

Title:	Immediate release oral guaifenesin solution
Abstract:	Disclosed is a method of treating or ameliorating a condition which can be treated or ameliorated by the administration of guaifenesin, which method comprises orally administering to a subject in need thereof an effective amount of an immediate release solution for oral administration of guaifenesin and at least one additional drug. In addition to water the solution comprises as solvents propylene glycol and glycerol in a concentration which significantly increases the bioavailability of guaifenesin in the human body.
Inventor(s):	Paul Hafey
Assignee:	Sovereign Pharmaceuticals LLC
Application Number:	US15/796,938
Patent Claim Types: see list of patent claims	Use; Formulation; Dosage form;

US Patent 10,105,324: Guaifenesin Oral-Solution Claims, Exclusivity, and Patent Landscape

US Patent 10,105,324 protects a method of treating cough or cold with an immediate-release guaifenesin oral solution containing water, propylene glycol, and glycerol. The central limitation is pharmacokinetic performance: a 200 mg guaifenesin dose must achieve specified Cmax or AUC exposure and maintain a therapeutically effective plasma concentration for at least four hours. The patent does not broadly claim every guaifenesin liquid or every guaifenesin combination product.

The claims create two principal protection categories:

1. A formulation-defined method requiring specified propylene glycol and glycerol concentrations.
2. A comparative pharmacokinetic method requiring materially higher guaifenesin exposure than an otherwise comparable aqueous solution.

The patent is most relevant to immediate-release liquid products containing guaifenesin with pseudoephedrine, phenylephrine, an antihistamine, an analgesic, or an antitussive.

What does US Patent 10,105,324 protect?

The patent protects administering a qualifying oral solution to treat or ameliorate cough or cold. The claims are method claims rather than simple composition claims.

Core claim architecture

Claim feature	Claims affected	Commercial significance
Treatment of cough or cold	1, 16	Requires a therapeutic administration, not merely manufacture or sale
Oral administration	1, 16	Covers use of the product by mouth
Immediate-release solution	1, 16	Excludes extended-release, delayed-release, and solid dosage forms
Guaifenesin	1, 16	Required active ingredient
Additional drug	1-20	Requires at least one antitussive, decongestant, antihistamine, or analgesic
Water solvent	1, 16	Required
Propylene glycol and glycerol	1-9, 16-18	Required expressly or functionally
48%-72% combined propylene glycol/glycerol	1, 2, 18	Main numeric formulation limitation
Glycerol-to-propylene-glycol ratio of 1.7:1-2.5:1	3	Narrower formulation limitation
Propylene glycol at 15%-23%	4	Narrower formulation limitation
Glycerol at 33%-49%	5	Narrower formulation limitation
Guaifenesin Cmax of at least 3,600 ng/mL	1	Pharmacokinetic threshold
Guaifenesin AUC(0-inf) of at least 3,700 ng·hr/mL	1	Alternative pharmacokinetic threshold
Effective plasma concentration for at least four hours	1, 16	Required duration limitation
Cmax of at least 3,800 or 4,000 ng/mL	6, 7	More demanding dependent limitations
AUC of at least 3,900 or 4,100 ng·hr/mL	8, 9	More demanding dependent limitations
1.5-fold or 1.4-fold improvement over aqueous control	16	Functional comparative limitation
1.6-fold Cmax and 1.5-fold AUC improvement	17	Narrower comparative limitation

The claims require a single dose that provides 200 mg of guaifenesin when administered to an adult human subject. The dose language is important because the pharmacokinetic thresholds are tied to a standardized dose rather than to the product's full labeled dose.

How do claims 1 through 15 differ from claims 16 through 20?

Claims 1 through 15 use fixed or semi-fixed formulation and pharmacokinetic parameters. Claims 16 through 20 rely primarily on comparison with an aqueous control.

Claims 1-15: concentration and exposure claims

Independent claim 1 requires:

• an immediate-release oral solution;
• guaifenesin;
• at least one additional cough-and-cold drug;
• water;
• a combined propylene glycol and glycerol concentration of 48%-72% by weight;
• either Cmax of at least 3,600 ng/mL or AUC(0-inf) of at least 3,700 ng·hr/mL; and
• therapeutically effective guaifenesin plasma levels for at least four hours.

Claims 2-9 narrow the formulation or pharmacokinetic profile. The narrowest formulation range is created by combining claims 2, 3, 4, and 5:

• total propylene glycol plus glycerol: 54%-66%;
• glycerol-to-propylene-glycol ratio: 1.7:1-2.5:1;
• propylene glycol: 15%-23%; and
• glycerol: 33%-49%.

Claims 6-9 create higher exposure tiers. Claim 9 requires Cmax of at least 4,000 ng/mL and AUC of at least 4,100 ng·hr/mL.

Claims 10-15 identify additional drug categories. They cover products containing pseudoephedrine, phenylephrine, an antihistamine, an analgesic, or an antitussive.

Claims 16-20: comparative bioavailability claims

Claim 16 does not specify the 48%-72% solvent range. Instead, it requires that the propylene glycol/glycerol solution outperform a specified aqueous solution containing the same concentrations of guaifenesin and the additional drug.

The thresholds are:

• Cmax at least 1.5 times the aqueous control and/or AUC at least 1.4 times the control; and
• a therapeutically effective plasma concentration for at least four hours.

Claim 17 raises both thresholds:

• Cmax at least 1.6 times the control; and
• AUC at least 1.5 times the control.

Claim 18 then adds the 48%-72% solvent requirement to claim 17. Claims 19 and 20 narrow the additional-drug categories.

The comparative-control language may create a separate infringement theory, but it also creates proof issues. A rights holder would need to establish the identity and concentration of the control formulation, the relevant pharmacokinetic study conditions, and the meaning of "therapeutically effective plasma concentration."

What formulation is required by the patent?

The claimed solvent system contains water, propylene glycol, and glycerol. In claims 1-9 and 18, the combined amount of propylene glycol and glycerol must fall within 48%-72% by weight of the finished solution.

A formulation within the dependent-claim ranges would generally contain:

Component	Claimed range
Propylene glycol	15%-23% by weight
Glycerol	33%-49% by weight
Combined propylene glycol and glycerol	54%-66% by weight
Glycerol:propylene glycol ratio	1.7:1-2.5:1

The claims do not require a particular brand, flavor, preservative, colorant, sweetener, container, or manufacturing process. Those elements may matter for regulatory compliance and product development, but they are not stated limitations in the supplied claims.

The claims also do not require a specific decongestant. Pseudoephedrine and phenylephrine are expressly identified, but claims 10-12 do not exclude other decongestants if the other claim limitations are met.

What pharmacokinetic performance must a product achieve?

The principal performance requirements are summarized below.

Claim	Cmax requirement	AUC(0-inf) requirement	Four-hour concentration requirement
1	At least 3,600 ng/mL and/or	At least 3,700 ng·hr/mL	Yes
6	At least 3,800 ng/mL	Claim 6 depends on claim 1	Yes
7	At least 4,000 ng/mL	Claim 7 depends on claim 1	Yes
8	Claim 8 depends on claim 6	At least 3,900 ng·hr/mL	Yes
9	At least 4,000 ng/mL	At least 4,100 ng·hr/mL	Yes
16	At least 1.5 times aqueous control and/or	At least 1.4 times aqueous control	Yes
17	At least 1.6 times aqueous control	At least 1.5 times aqueous control	Yes

Cmax and AUC are not interchangeable in the dependent claims. A product that satisfies a Cmax threshold may not satisfy an AUC threshold, and vice versa, unless the claim language requires both. Claims 1 and 16 use "and/or" structures, while claim 17 requires both comparative thresholds.

The phrase "therapeutically effective plasma concentration" is a further limitation. It is not enough for a product to reach the required peak or total exposure. The concentration must remain therapeutically effective for at least four hours under the claim's applicable testing conditions.

How strong is the patent estate for guaifenesin oral solutions?

The supplied claims indicate a targeted, technically narrow estate rather than a broad platform patent.

Strengths

The claims combine several limitations that can increase design-around difficulty:

• a specific dosage form;
• a multi-solvent system;
• narrow concentration ranges;
• a defined guaifenesin dose;
• adult-human pharmacokinetics;
• a four-hour therapeutic concentration requirement; and
• a required additional cough-and-cold active.

The dependent claims also provide fallback positions. A product may fall outside claim 1 but still be relevant to the separate comparative claims in claims 16-20 if it produces the required exposure improvement over the aqueous control.

Weaknesses and enforcement issues

The estate has several potential limitations:

1. Method-of-treatment form. The claims are directed to administration, not simply to the formula. A product manufacturer would face a stronger direct-infringement case if its labeling instructs consumers to administer the product in the claimed manner.

2. Pharmacokinetic proof. Infringement may require clinical or comparative pharmacokinetic testing. Label content alone may not establish Cmax, AUC, or four-hour therapeutic exposure.

3. Adult 200 mg dose limitation. Products labeled only for children, products administered at materially different doses, or products whose labeled dosing cannot provide 200 mg may present a noninfringement position.

4. Immediate-release requirement. Extended-release guaifenesin tablets, capsules, and other dosage forms do not fall within the supplied claims.

5. Additional-drug requirement. A guaifenesin-only solution is outside the express scope of claims 1 and 16.

6. Comparative-control requirement. Claims 16-20 require comparison against an aqueous solution with the same active-drug concentrations. Differences in dose, composition, assay method, food conditions, or subject population could affect the analysis.

What generic entry risks exist for products covered by US 10,105,324?

The practical risk depends on whether a competitor's product and labeling meet all claim elements.

High-risk product profile

A competitor presents the highest infringement risk if it sells an adult cough-and-cold liquid that:

• contains guaifenesin and pseudoephedrine, phenylephrine, dextromethorphan, an antihistamine, or an analgesic;
• is an immediate-release oral solution;
• uses water with approximately 15%-23% propylene glycol and 33%-49% glycerol;
• contains 48%-72% combined propylene glycol and glycerol;
• provides 200 mg guaifenesin per relevant dose; and
• delivers the claimed Cmax, AUC, and four-hour exposure.

Lower-risk design-around profiles

Potentially lower-risk profiles include:

• a guaifenesin-only solution;
• a solid tablet or capsule;
• an extended-release product;
• a liquid using polyethylene glycol, ethanol, sorbitol, or another solvent system instead of the claimed propylene glycol/glycerol combination;
• a formulation outside the claimed solvent ranges;
• a product not labeled to administer 200 mg guaifenesin to an adult;
• a product whose pharmacokinetic exposure is below the thresholds; or
• a formulation that does not include an additional drug in a claimed category.

These positions require product-specific claim charting. The concentration ranges should be assessed both literally and under potential equivalents theories.

What is the FDA and Orange Book significance?

The claims cover OTC-style cough-and-cold products, but a patent's Orange Book status cannot be inferred from the claim language alone.

The FDA Orange Book generally lists patents submitted for approved new drug applications under section 505 of the Federal Food, Drug, and Cosmetic Act. Many nonprescription cough-and-cold products are marketed under OTC monograph pathways rather than through an NDA with a corresponding Orange Book patent listing.[1] A method patent covering an OTC formulation may therefore have limited or no Orange Book relevance even if it creates commercial litigation risk.

Regulatory implications

The patent does not itself establish:

• FDA approval;
• monograph compliance;
• an NDA;
• an ANDA pathway;
• a period of FDA marketing exclusivity; or
• a listed patent under 21 U.S.C. § 355.

Guaifenesin products are subject to the FDA OTC monograph framework for cough and cold products, including applicable active-ingredient, labeling, dosage, and combination restrictions.[2] The patent analysis must therefore be separated from FDA exclusivity analysis.

When does US Patent 10,105,324 lose exclusivity?

The patent's enforceable term depends on its effective filing date, patent-term adjustment, terminal disclaimer, and any applicable patent-term extension. The grant date alone does not determine expiration.

US Patent 10,105,324 was granted on October 23, 2018. Under the ordinary US patent-term rule, utility patents generally expire 20 years from the earliest effective nonprovisional filing date, subject to statutory adjustments.[3] The patent's precise expiration date must be taken from the USPTO patent record and the patent's term calculation.

The claims are not a basis for asserting FDA orphan-drug exclusivity, pediatric exclusivity, or biologic exclusivity. Those regulatory exclusivities are separate from patent rights.

Are there Paragraph IV challenges to US 10,105,324?

A Paragraph IV certification is generally used in an ANDA challenging an Orange Book-listed patent. Because the claimed products are cough-and-cold oral solutions that may be marketed under OTC pathways, a conventional ANDA Paragraph IV dispute may not be the primary route for challenging this patent.

A competitor could instead:

• launch a product designed to avoid the claims;
• seek a declaratory judgment;
• challenge validity or enforceability in district court;
• petition for inter partes review at the Patent Trial and Appeal Board; or
• rely on regulatory pathways that do not require an ANDA certification.

The supplied claim set raises potential validity questions involving written description, enablement, anticipation, obviousness, indefiniteness, and the evidentiary support for pharmacokinetic thresholds. Those issues cannot be resolved from the claims alone. A final validity assessment requires the specification, prosecution history, cited prior art, issued claim amendments, and any terminal disclaimer or reexamination record.

What patent litigation or settlement affects the patent?

No litigation, settlement, licensing agreement, or Paragraph IV case can be established from the supplied claims alone. A reliable litigation assessment must be tied to the patent's USPTO and PACER records, PTAB proceedings, and FDA listing data.

The principal litigation theories would likely concern:

• whether a competitor's label induces the claimed administration;
• whether the product is an immediate-release solution;
• whether solvent concentrations fall inside the numerical ranges;
• whether the 200 mg dose generates the required exposure;
• whether the comparator in claims 16-20 is properly constructed;
• whether the four-hour therapeutic-concentration limitation is met; and
• whether the patent is invalid over earlier guaifenesin liquid formulations or pharmacokinetic studies.

How does this patent compare with conventional guaifenesin patents?

Patent type	Typical protected subject matter	Relationship to US 10,105,324
Composition patent	Chemical compound, salt, or excipient combination	This patent is narrower and method-focused
Formulation patent	Specific liquid, tablet, suspension, or release profile	This patent protects a solution only when performance and treatment limitations are met
Method-of-use patent	Treating cough, cold, congestion, or respiratory symptoms	This patent is a method-of-use claim with formulation restrictions
Manufacturing patent	Mixing, processing, filling, or stabilization method	The supplied claims do not recite manufacturing steps
Regulatory exclusivity	FDA marketing protection	Separate from the patent and not established by the claims

The patent's commercial value is concentrated in branded or private-label combination liquids that use the claimed solvent system and deliver enhanced guaifenesin exposure. It has less relevance to plain guaifenesin tablets, extended-release products, pediatric-only products, or formulations using materially different excipients.

Key Takeaways

• US Patent 10,105,324 claims treatment with an immediate-release guaifenesin oral solution, not every guaifenesin product.
• The key formulation range is 48%-72% combined propylene glycol and glycerol.
• Narrower claims require 54%-66% combined solvents, a 1.7:1-2.5:1 glycerol-to-propylene-glycol ratio, 15%-23% propylene glycol, and 33%-49% glycerol.
• The product must provide specified guaifenesin Cmax or AUC exposure after a 200 mg adult dose.
• All independent claims require therapeutically effective plasma concentrations for at least four hours.
• Claims 16-20 use comparative pharmacokinetic thresholds against an aqueous solution.
• Products containing pseudoephedrine, phenylephrine, antihistamines, analgesics, or antitussives are within the expressly identified combination scope.
• The patent is a targeted formulation and method-of-treatment asset, not a broad composition patent.
• Orange Book and Paragraph IV implications depend on the regulatory pathway and any actual FDA patent listing.
• Patent expiration must be confirmed from the USPTO term record rather than inferred solely from the 2018 grant date.

FAQs

Does US 10,105,324 cover guaifenesin tablets?

No. The supplied claims require an immediate-release solution for oral administration. A tablet or capsule would not satisfy that dosage-form limitation.

Does a guaifenesin-only liquid infringe the claims?

The supplied independent claims require guaifenesin plus at least one additional drug from the claimed antitussive, decongestant, antihistamine, or analgesic categories. A guaifenesin-only product is outside the literal scope of those claims.

Can a formulation avoid the patent by changing only the glycerol-to-propylene-glycol ratio?

It may avoid claims containing the ratio limitation, such as claim 3, but it could remain exposed to broader claims if the total solvent concentration and pharmacokinetic requirements are still met.

Does the patent cover phenylephrine-guaifenesin liquid products?

Yes, claim 12 expressly identifies phenylephrine and its pharmaceutically acceptable salts as a claimed decongestant, subject to the remaining formulation, dosage, pharmacokinetic, and treatment limitations.

Is FDA approval required to infringe the patent?

No. Patent infringement and FDA approval are separate issues. The relevant question is whether the accused conduct satisfies the issued claim limitations, including administration, formulation, dose, and pharmacokinetic requirements.

References

1. U.S. Food and Drug Administration. (n.d.). Approved drug products with therapeutic equivalence evaluations. FDA.
2. U.S. Food and Drug Administration. (n.d.). Over-the-counter monograph for cough, cold, allergy, bronchodilator, and antiasthmatic drug products. FDA.
3. United States Code, 35 U.S.C. §§ 154, 156, 271, 282.
4. U.S. Patent No. 10,105,324. (2018). Issued claims concerning guaifenesin immediate-release oral solutions for cough and cold treatment. United States Patent and Trademark Office.

Drugs Protected by US Patent 10,105,324

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Patented / Exclusive Use	Submissiondate
Sovereign Pharms	OBREDON	guaifenesin; hydrocodone bitartrate	SOLUTION;ORAL	205474-001	Nov 14, 2014		DISCN	Yes	No	10,105,324		Y	Y		A METHOD OF INCREASING THE BIOAVAILABILITY OF GUAIFENESIN IN A SOLUTION CONTAINING 54% TO 66% BY WEIGHT OF PROPYLENE GLYCOL AND GLYCEROL, WHEREIN THE METHOD INCREASES THE CMAX BY AT LEAST 1.5 AND/OR INCREASES THE AUC (0-INF) BY AT LEAST 1.4