US Patent 8,263,647: Claim Scope, Patent Strength, Expiration and Generic Entry Analysis

US Patent 8,263,647 protects specific ibuprofen-diphenhydramine combinations designed for pain-associated sleep disturbance. Its strongest technical limitations are the dosage-form architecture: a bilayer solid dosage form separating ibuprofen from diphenhydramine, or a polyethylene glycol-based liquid composition enclosed in a soft gelatin capsule. The patent does not broadly cover every ibuprofen-diphenhydramine product.

The principal commercial relevance is to nighttime analgesic products such as ibuprofen-diphenhydramine softgels and caplets. The patent estate is materially narrower than a composition patent covering the active ingredients alone because infringement generally requires the claimed dosage form, ingredient allocation, concentration range, and, for claim 9, polyethylene glycol and softgel structure.

What does US Patent 8,263,647 protect?

The patent has three practical claim groups:

Claim group	Dosage form	Core limitations	Commercial relevance
Claims 1-8	Bilayer solid	All ibuprofen in one layer; diphenhydramine in a separate layer; specified dose ranges	Bilayer tablets or caplets
Claims 9-17	Liquid-filled softgel	Ibuprofen and diphenhydramine in liquid composition; polyethylene glycol; soft gelatin capsule	Liquid-filled nighttime analgesic softgels
Claim 18	Bilayer solid with excipients	Separate ibuprofen and diphenhydramine layers; interaction minimization; at least one listed excipient	Manufacturing-specific solid products

The patent is directed to a formulation problem: ibuprofen and diphenhydramine may interact in a combined dosage form. The claims address that problem through physical separation in a bilayer tablet or through a PEG-containing liquid formulation in a softgel.

The claims do not cover:

Ibuprofen alone;
Diphenhydramine alone;
A conventional single-layer tablet merely containing both ingredients;
A capsule containing the two drugs without the claimed PEG formulation;
A product using another analgesic, such as acetaminophen, instead of ibuprofen;
A product with the two ingredients in separate packages rather than in one claimed dosage form.

How broad are claims 1 through 8?

Claim 1 is the principal bilayer composition claim. Literal infringement requires a solid dosage form with all of the following elements:

Ibuprofen and diphenhydramine.
A therapeutic amount directed to a pain-associated sleep disturbance.
A bilayer configuration.
A first layer containing all of the ibuprofen.
A second layer containing diphenhydramine or a salt.
Ibuprofen in an amount from 50 mg to 800 mg.
Diphenhydramine in an amount from 12.5 mg to 50 mg.

The phrase "all of the ibuprofen" is important. A tablet containing ibuprofen in both layers would create a substantial noninfringement argument under the literal claim language. A product with diphenhydramine in both layers could also challenge infringement because the claim places the diphenhydramine in the second layer, although the claim does not expressly state that the second layer must contain all of the diphenhydramine.

Claim 1 covers a broad dose range, but the dosage-form requirement substantially narrows practical coverage. A 200 mg ibuprofen and 25 mg diphenhydramine HCl bilayer tablet falls within the express numerical ranges.

Dependent-claim narrowing

Claim	Added limitation
2	Ibuprofen at 200 mg
3	Diphenhydramine HCl or diphenhydramine citrate
4	Repeats the salt selection in claim 3
5	Diphenhydramine HCl at 25 mg
6	Diphenhydramine citrate at 19 mg to 38 mg
7	Diphenhydramine citrate at 38 mg
8	Sleep disturbance affects sleep duration

Claims 3 and 4 appear substantively duplicative. That drafting issue does not necessarily invalidate either claim, but it can create claim-construction and prosecution-history questions. Claim 8 adds a functional limitation tied to sleep duration. It is narrower than claim 1 but may provide limited practical distinction if the accused product is expressly labeled for difficulty sleeping or reduced sleep duration.

How broad are claims 9 through 17?

Claim 9 covers a different product architecture: a liquid formulation placed inside a soft gelatin capsule.

The claim requires:

Ibuprofen at approximately 200 mg to 400 mg;
Diphenhydramine at approximately 10 mg to 50 mg;
A liquid composition;
A soft gelatin capsule;
Polyethylene glycol as a solubilizing agent;
PEG functioning to prevent negative interactions between the active ingredients.

The softgel requirement excludes ordinary compressed tablets, hard capsules containing powder, and liquid bottles. The PEG limitation is also significant. A liquid-filled softgel using a different solubilizer could assert noninfringement, subject to any doctrine-of-equivalents analysis.

The use of "consisting of" in the phrase describing the solubilizing agent may restrict the claim more than the term "comprising." A formulation that includes PEG plus another solubilizer could present a claim-construction issue. The claim also uses "about," which introduces ordinary pharmaceutical measurement tolerance rather than an unlimited numerical range.

Dependent claims 10 through 17

Claims 10 through 17 narrow claim 9 by specifying:

200 mg ibuprofen;
Diphenhydramine HCl or citrate;
12.5 mg to 50 mg diphenhydramine HCl;
25 mg diphenhydramine HCl;
19 mg to 38 mg diphenhydramine citrate;
38 mg diphenhydramine citrate;
A sleep disturbance affecting sleep duration.

A product containing 200 mg ibuprofen and 38 mg diphenhydramine citrate in a PEG-based liquid-filled softgel is the clearest commercial embodiment within this claim family.

What does claim 18 add to the patent?

Claim 18 is the most commercially important solid-dosage-form claim because it combines the bilayer structure with an excipient list.

The claim requires:

A solid dosage form;
Ibuprofen and diphenhydramine;
Treatment of a pain-associated sleep disturbance;
A first layer containing all of the ibuprofen;
A second layer containing diphenhydramine or a salt;
Separation intended to minimize negative interaction;
At least one of the listed excipients.

The listed excipients include calcium stearate, croscarmellose sodium, glyceryl behenate, lactose, microcrystalline cellulose, colloidal silicon dioxide, sodium lauryl sulfate, sodium starch glycolate, corn starch, pregelatinized starch, starch, and stearic acid.

Because the claim requires only one listed excipient, most conventional pharmaceutical tablets would likely satisfy the excipient element. The principal infringement issues remain the bilayer configuration and allocation of all ibuprofen to the first layer.

Claim 18 does not specify the ibuprofen or diphenhydramine dose. It could therefore reach a broader dose range than claims 1 through 8, subject to the requirement that the product be effective for the claimed therapeutic purpose.

What formulations are protected by US 8,263,647?

The patent protects two different formulation strategies.

Bilayer tablet or caplet

A potentially covered product would have:

Ibuprofen in layer one;
Diphenhydramine HCl or citrate in layer two;
No ibuprofen in layer two;
A solid, physically distinct bilayer structure;
A claimed excipient in the case of claim 18.

A single-layer compressed tablet containing both active ingredients is outside the literal scope of the bilayer limitations.

Liquid-filled softgel

A potentially covered product would have:

A liquid ibuprofen-diphenhydramine formulation;
PEG as a solubilizing agent;
Encapsulation in soft gelatin;
The claimed dose ranges.

A softgel filled with a suspension rather than a PEG-based solution may create a noninfringement position, depending on the formulation composition and claim construction.

How strong is the patent estate?

The patent has moderate technical strength but limited breadth.

Strength factor	Assessment
Active-ingredient coverage	Narrow. The patent requires both ibuprofen and diphenhydramine
Dosage-form coverage	Narrow but commercially meaningful
Bilayer protection	Strongest feature for solid products
Softgel protection	Dependent on PEG and liquid-composition limitations
Dose-range coverage	Broad in independent claims, narrower in dependent claims
Manufacturing relevance	Significant for products using physical separation
Design-around potential	Moderate to high
Product-label dependence	Functional treatment language may create claim-construction issues
Biosimilar relevance	None in the biologic sense
Generic risk	Higher after patent-term expiration or for products avoiding the claimed structures

The patent is stronger against a direct copy of the disclosed product architecture than against a redesigned combination product. A competitor can potentially avoid the principal claims by changing one or more of the following:

Using a single-layer tablet;
Distributing ibuprofen between layers;
Using a non-PEG liquid formulation;
Using a hard capsule;
Separating the actives into separate dosage units;
Using a different analgesic;
Changing the formulation so the product does not meet the claimed functional or structural limitations.

The doctrine of equivalents could reduce the value of some design-arounds, but prosecution history and the specificity of the bilayer and PEG limitations would be central to that analysis.

When does US Patent 8,263,647 lose exclusivity?

Patent term is governed principally by 35 U.S.C. § 154 and generally runs for 20 years from the earliest effective nonprovisional filing date, subject to patent-term adjustment, terminal disclaimers, and any applicable statutory extensions.

The patent issued on September 11, 2012. Its ordinary expiration is tied to the family’s earliest effective nonprovisional filing date, not to the issue date. The claims supplied alone do not establish the controlling priority date, patent-term adjustment, terminal disclaimer status, or any extension. The exact expiration date therefore cannot be determined from the claim text alone.

A business assessment should distinguish:

Patent expiration;
FDA marketing exclusivity;
OTC monograph status;
Orange Book listing status;
Any continuing or related patent family rights.

Expiration of this patent would remove its direct barrier to products practicing the claims, but it would not eliminate other patents covering manufacturing processes, packaging, softgel shells, excipients, trademarks, or separate drug products.

What is the Orange Book status of this patent?

US Patent 8,263,647 should not automatically be treated as an Orange Book patent.

Orange Book listing depends on the reference product, approved application, patent submission, and FDA listing requirements. A patent covering an over-the-counter formulation may be absent from the Orange Book if the product is marketed under an OTC monograph rather than an approved NDA. Conversely, an NDA-based OTC product may have listed patents.

The patent number and claim text do not establish:

Whether the patent was submitted to FDA;
Whether it was listed against a specific NDA;
Whether it was delisted;
Whether an FDA use code was assigned;
Whether a Paragraph IV certification was filed.

The Orange Book should be checked by product, NDA, and active ingredient rather than by patent number alone. FDA, Approved Drug Products with Therapeutic Equivalence Evaluations, is the controlling public source for listed patents and exclusivity data (U.S. Food and Drug Administration, n.d.-a).

Which companies are challenging the patent?

A Paragraph IV challenge is relevant only when an ANDA applicant certifies that a listed patent is invalid, unenforceable, or will not be infringed. The supplied claims do not identify an ANDA, applicant, notice letter, district-court action, or settlement.

The commercial field includes branded and private-label nighttime analgesic products using ibuprofen and diphenhydramine. Potential market participants include the manufacturer of Advil PM and generic or store-brand manufacturers. Market presence alone does not establish a patent challenge.

No reliable conclusion about a Paragraph IV challenger, litigation defendant, or settlement party follows from the claims provided. Such conclusions require a patent-litigation and FDA listing record, not claim analysis.

What patent litigation affects US 8,263,647?

The principal litigation questions are likely to concern:

Whether the accused tablet is truly bilayer rather than a single compressed layer.
Whether all ibuprofen is located in the first layer.
Whether a softgel contains a PEG-based liquid composition.
Whether the accused product contains a listed diphenhydramine salt.
Whether the functional treatment language limits the claims.
Whether the patent was anticipated or rendered obvious by earlier combination products.
Whether the claims adequately describe and enable the full dose and formulation ranges.

The most substantial validity arguments would likely involve:

Obviousness based on known ibuprofen-diphenhydramine combinations;
Anticipation by prior bilayer or softgel formulations;
Written-description support for broad dose and excipient ranges;
Indefiniteness involving "negative interactions," "about," and therapeutic-effect language;
Terminal-disclaimer or double-patenting issues within the patent family.

The functional phrase "thereby minimizing the negative interaction" may be treated as a purpose or result limitation unless the specification and prosecution history show that it imposes a measurable structural requirement.

How does this patent compare with competing nighttime analgesic products?

Product type	Likely relationship to US 8,263,647
Ibuprofen-diphenhydramine bilayer tablet	Highest infringement risk
Ibuprofen-diphenhydramine PEG softgel	Highest risk under claims 9-17
Single-layer ibuprofen-diphenhydramine tablet	Potential design-around
Ibuprofen-diphenhydramine hard capsule	Generally outside softgel claims
Acetaminophen-doxylamine product	Different active ingredients, outside these claims
Ibuprofen-only product	Outside the claims
Diphenhydramine-only sleep-aid product	Outside the claims
Separate ibuprofen and diphenhydramine dosage units	Likely outside the single-dosage-form claims

The patent does not create exclusivity over the broader nighttime analgesic category. Its commercial value depends on whether the market product uses the same actives and the same physical formulation architecture.

What generic launch risks exist?

Before expiration, a generic applicant copying a covered softgel or bilayer tablet would face formulation and litigation risk if the patent were listed against the reference product. The applicant could pursue:

A Paragraph IV certification;
A formulation design-around;
A noninfringement position based on single-layer structure;
A different solubilizer instead of PEG;
A different dosage form;
A separate-product strategy.

After expiration, the patent no longer blocks a product that practices the claims, but regulatory approval, bioequivalence, labeling, manufacturing, trademark, and other patent issues remain relevant.

The highest-risk launch scenario is a direct copy of a 200 mg ibuprofen and 25 mg or 38 mg diphenhydramine product using the same bilayer or PEG-softgel architecture. The lower-risk scenario is a product using a different dosage form or a formulation that does not physically separate the ingredients in the claimed manner.

Key Takeaways

US 8,263,647 is a formulation patent, not a broad active-ingredient patent.
Claims 1 through 8 target bilayer solid dosage forms.
Claims 9 through 17 target PEG-based liquid formulations in soft gelatin capsules.
Claim 18 is the broadest solid-form claim because it omits express dose limits but requires physical separation and a listed excipient.
"All of the ibuprofen" in the first layer is a material limitation.
A conventional single-layer tablet is the clearest potential design-around.
A softgel without PEG may avoid the literal scope of claims 9 through 17.
The claims do not establish Orange Book listing, Paragraph IV activity, litigation, or settlement history.
The patent’s exact expiration date requires the complete priority and term-adjustment record.
Biosimilar risk is not relevant because this is a small-molecule formulation patent.
The most exposed products are direct copies of ibuprofen-diphenhydramine bilayer tablets or PEG-based liquid softgels.

FAQs

Does US 8,263,647 cover Advil PM by brand name?

No. Patent claims cover technical product characteristics, not trademarks. A branded product is relevant only if its formulation satisfies the issued claim limitations.

Does the patent cover ibuprofen and diphenhydramine in the same tablet?

Only if the tablet satisfies the structural limitations. The principal solid claims require a bilayer arrangement with all ibuprofen in one layer and diphenhydramine in the other.

Can a competitor sell ibuprofen and diphenhydramine in separate tablets?

The supplied claims generally require a single solid dosage form or a single softgel formulation. Separate tablets may avoid these claims, although other patents, regulatory requirements, or combination-product rules could apply.

Is diphenhydramine citrate interchangeable with diphenhydramine HCl under the patent?

The claims expressly identify both salts in specified dependent claims. A product using another salt would require a separate infringement analysis and may not fall within those dependent claims.

Does patent expiration automatically permit a generic nighttime analgesic launch?

No. Patent expiration removes this patent as a barrier but does not resolve FDA approval, bioequivalence, labeling, manufacturing, trademark, Orange Book, or other patent issues.

References

United States Patent and Trademark Office. (2012). U.S. Patent No. 8,263,647, pharmaceutical compositions comprising ibuprofen and diphenhydramine. U.S. Department of Commerce.
U.S. Food and Drug Administration. (n.d.-a). Approved drug products with therapeutic equivalence evaluations. U.S. Department of Health and Human Services.
U.S. Food and Drug Administration. (n.d.-b). Drugs@FDA: FDA-approved drugs. U.S. Department of Health and Human Services.
U.S. Code, 35 U.S.C. § 154. (2024). Contents and term of patent; provisional rights.
U.S. Code, 21 U.S.C. § 355. (2024). New drugs.

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Austria	309797	⤷ Start Trial
Canada	2434484	⤷ Start Trial
Germany	60207383	⤷ Start Trial
Denmark	1363608	⤷ Start Trial
European Patent Office	1363608	⤷ Start Trial
Spain	2251584	⤷ Start Trial
Hong Kong	1060045	⤷ Start Trial
>Country	>Patent Number	>Estimated Expiration	>Supplementary Protection Certificate	>SPC Country	>SPC Expiration

Details for Patent: 8,263,647

Summary for Patent: 8,263,647