United States Drug Patent 5,534,554: Claim Scope, Expiration, and Docosanol Patent Landscape

U.S. Patent No. 5,534,554 protected stabilized topical creams containing long-chain aliphatic alcohols, particularly n-docosanol, combined with sugar-ester surfactants, mineral oil, water, and specified emollient co-solvents. The claims covered both compositions and methods of treating viral infection, inflammation, and pain on skin or mucous membranes.

The patent issued on July 9, 1996, and expired on January 26, 2013, based on its effective priority date. It no longer blocks generic or competing docosanol products in the United States. Its historical importance is tied to Abreva, the 10% docosanol cold-sore cream commercialized in the United States. The patent did not protect docosanol as a molecule, and it does not provide current market exclusivity for docosanol cream. [1]

What did U.S. Patent 5,534,554 protect?

The patent protected formulation architecture rather than the active ingredient alone. Its principal technical elements were:

Element	Role in the claims
Long-chain aliphatic alcohol	Therapeutic component, primarily n-docosanol
Carbon chain	C20-C28 alcohols, including n-icosanol through n-octacosanol
Sugar-based ester surfactant	Sucrose cocoate, sucrose stearates, or sucrose distearate
Oil phase	Mineral oil
Co-solvent or emollient	Benzyl alcohol, ethyl hexanediol, or polyoxypropylene stearyl ether
Aqueous phase	Water
Physical property	Stability at at least 40°C for at least three months and after repeated freeze-thaw cycles
Uses	Treatment or prevention of viral infection, inflammation, and inflammatory pain

The claims are directed to a stable cream or a method of applying such a cream. They do not claim purified n-docosanol, n-docosanol manufacturing, a tablet, an oral dosage form, or every topical composition containing docosanol.

How are the independent claims structured?

The patent contains seven principal independent claim groups: claims 1, 4, 9, 14, 16, 18, and 20.

Claim 1: n-docosanol cream with stability limitations

Claim 1 requires a therapeutic cream consisting essentially of:

A sugar-based ester surfactant;
More than approximately 5% by weight n-docosanol;
Mineral oil;
An emollient co-solvent; and
Water.

The cream must be stable at temperatures of at least 40°C for at least three months and must remain stable after repeated freeze-thaw cycles.

This is a formulation claim with a meaningful physical-stability limitation. A product would need to satisfy both the ingredient limitations and the specified stability performance. The claim is not limited to a 10% docosanol concentration. It covers concentrations above approximately 5%, subject to the other limitations.

Claim 4: broader C20-C28 alcohol genus

Claim 4 expands the active ingredient from n-docosanol to a defined genus of C20-C28 alcohols:

n-Icosanol;
n-Henicosanol;
n-Docosanol;
n-Tricosanol;
n-Tetracosanol;
n-Pentacosanol;
n-Hexacosanol;
n-Heptacosanol; and
n-Octacosanol.

The active alcohol must exceed approximately 5% by weight. Claim 4 otherwise retains the cream-base requirements and the stability limitations.

This claim is broader than claim 1 chemically, but it may be narrower commercially because most market products focus on n-docosanol rather than the full C20-C28 genus.

Claim 9: therapeutic composition plus cream base

Claim 9 divides the product into:

A therapeutic composition consisting essentially of one or more C20-C28 long-chain aliphatic alcohols; and
A cream base containing sugar esters and one or more specified co-solvents.

Unlike claim 1, claim 9 does not expressly recite mineral oil and water in the claim text supplied. It also does not expressly include the stability requirement appearing in claims 1 and 4.

That distinction creates a potentially broader composition claim, although the claim remains limited by the specified cream-base ingredients.

Claim 14: method of treatment

Claim 14 covers applying a stable topical cream to a person for viral infection or inflammation of skin or mucous membranes. The cream must contain:

n-Docosanol as the therapeutic active;
A sugar-based ester surfactant;
A C20-C28 long-chain aliphatic alcohol;
Mineral oil;
An emollient co-solvent; and
Water.

The claim has an unusual overlap: n-docosanol is both the specifically named therapeutic active and a member of the recited long-chain alcohol group. That drafting structure may require claim construction concerning whether the claim requires separate quantities or merely the same compound satisfying both descriptions.

Claims 16 and 18: specific concentration ranges

Claims 16 and 18 are the most formulation-specific claims. They recite concentration ranges for:

n-Docosanol: 5% to 20%;
Sucrose stearates: 0% to 15%;
Sucrose cocoate: 0% to 10%;
Sucrose distearate: 0% to 10%;
Mineral oil: 3% to 15%;
Propylene glycol: 2% to 10%;
Polyoxypropylene stearyl ether: up to 5%;
Benzyl alcohol: 0.5% to 5% in claim 16;
Water: 40% to 70%.

The claims also require:

At least one sucrose ester;
At least approximately 3% total sucrose ester;
Either polyoxypropylene stearyl ether or benzyl alcohol at or above approximately 1%.

Claim 18 is a cream claim, while claim 16 is a method claim. Claim 17 and claim 19 increase the sucrose-ester requirement to approximately 10% plus or minus 5%.

Claim 20: broad pain-treatment claim

Claim 20 is structurally the broadest independent claim. It covers reducing pain from surface inflammation by applying a physiologically compatible carrier containing a C20-C28 long-chain aliphatic alcohol at approximately 5% to 25% by weight.

It does not require:

A sugar ester;
Mineral oil;
Water;
A named co-solvent;
A stability test; or
n-docosanol specifically.

Claim 20 therefore reaches beyond the detailed cream formulations. Claim 21 narrows the carrier to a cream base containing a sugar ester and a specified co-solvent. Claim 22 narrows the active to n-docosanol.

What formulations are protected by the dependent claims?

The dependent claims focus on three commercial formulation variables: the identity of the sugar ester, the identity of the co-solvent, and the concentration of the active alcohol.

Claim	Main limitation
2	Sugar surfactant is sucrose cocoate, sucrose stearate, or sucrose distearate
3	Co-solvent is polyoxypropylene stearyl ether, ethyl hexanediol, benzyl alcohol, or a combination
5	Sucrose ester content is at least approximately 3%
6	Sucrose ester content is approximately 10% plus or minus 5%
7	Claim 6 formulation with a specified co-solvent
8	Long-chain alcohol is at least approximately 10%
10	Sugar ester is approximately 10% plus or minus 5%
11	Long-chain alcohol is at least approximately 10%
12	Active is n-docosanol
13	Defined formulation ranges with mineral oil, benzyl alcohol, water, and C20-C28 alcohol
15	n-Docosanol is more than half of the long-chain alcohol mixture
17	Sucrose ester is approximately 10% plus or minus 5% or more
19	Same higher sucrose-ester threshold for the cream of claim 18
21	Carrier contains a sugar ester and specified co-solvent
22	Long-chain alcohol consists essentially of n-docosanol

Claim 13 is particularly relevant to an Abreva-type product because it combines a 5%-15% long-chain alcohol range with sucrose esters, mineral oil, benzyl alcohol, and 45%-70% water.

How does “consisting essentially of” affect infringement analysis?

“Consisting essentially of” generally permits additional ingredients that do not materially alter the basic and novel characteristics of the claimed composition. The phrase is narrower than “comprising” but broader than “consisting of.”

For this patent, the basic and novel characteristics likely include:

Incorporation of a C20-C28 long-chain alcohol;
Formation of a topical cream using the specified sugar-ester system;
Acceptable therapeutic delivery; and
Stability under elevated-temperature and freeze-thaw conditions where those limitations apply.

An accused product containing preservatives, fragrances, pH adjusters, antioxidants, or viscosity modifiers would not automatically fall outside the claims. The legal question would be whether the added ingredient materially changes the claimed formulation characteristics.

The phrase does not eliminate the requirement to satisfy expressly recited ingredients or concentration ranges. A cream lacking mineral oil could avoid claims that require mineral oil, while a cream using a non-sugar surfactant could avoid claims requiring a sugar-based ester, subject to any broader claim that does not contain those elements.

When did U.S. Patent 5,534,554 lose exclusivity?

The patent expired on January 26, 2013. No current patent term remains under the patent number itself. Patent expiration ended the right to exclude others from practicing the claimed compositions and methods in the United States. [1]

Milestone	Date
Effective priority date	January 26, 1993
Patent issued	July 9, 1996
Nominal expiration	January 26, 2013
Current status	Expired

The patent therefore cannot support a present-day Paragraph IV litigation strategy. A generic applicant could still address the patent in an ANDA certification history, but an expired patent cannot create a current injunction risk based solely on its remaining term.

What was the FDA and Orange Book status of the docosanol product?

Docosanol 10% cream was approved by the FDA as an over-the-counter cold-sore treatment. The commercial product associated with the patent was Abreva, originally developed through Avanir-related commercialization activities and later marketed through major consumer-healthcare companies.

Docosanol is a small-molecule topical drug, not a biologic. Biosimilar regulations under the Public Health Service Act do not apply. The competitive pathway is therefore generic or OTC-market entry, not biosimilar substitution.

The FDA regulatory issues are separate from patent status:

The drug product must meet applicable FDA requirements for identity, strength, quality, and labeling.
A generic or private-label product may use an ANDA, an OTC monograph route where available, or another FDA-recognized pathway depending on the product and regulatory classification.
The absence of patent exclusivity does not eliminate formulation, manufacturing, labeling, or product-quality requirements.
Orange Book listings, if applicable to the relevant NDA and product presentation, identify listed patents and exclusivity information. Orange Book listing does not extend an expired patent. [2]

Because Abreva is an OTC topical product, market entry analysis must distinguish the regulatory reference product from the patent estate. A competitor can face FDA product-development requirements even when the principal formulation patent has expired.

Which companies challenged or competed against the patent?

The historical commercial competition has centered on manufacturers of docosanol 10% cream and private-label equivalents rather than on continuing litigation over U.S. Patent 5,534,554.

Relevant commercial participants include:

Avanir Pharmaceuticals, associated with the development and commercialization of docosanol;
The Liposome Company, associated with the underlying formulation technology;
GlaxoSmithKline Consumer Healthcare, historically associated with Abreva commercialization;
Haleon, which now holds the relevant consumer-healthcare commercial portfolio after the separation of GSK Consumer Healthcare; and
Generic and private-label manufacturers selling docosanol 10% cream.

The patent's expiration removed the principal composition barrier. Brand strength, consumer recognition, retailer access, manufacturing scale, and FDA-compliant labeling became more important than the expired patent.

What patent litigation affects docosanol cream?

U.S. Patent 5,534,554 does not present an active, term-based infringement risk today. Its expiration precludes an injunction based on the patent's unexpired term.

The patent could still appear in historical litigation, licensing records, prosecution histories, or regulatory patent certifications. Those records do not revive the patent or create new exclusivity.

No biosimilar litigation is relevant because docosanol is not a biologic. Any current dispute involving a docosanol product would more likely concern:

Trademark or trade dress;
False advertising;
Labeling;
Product quality;
Manufacturing know-how;
Trade secrets;
A later-filed formulation or delivery patent; or
Contractual licensing rights.

How strong was the patent estate?

The patent was commercially meaningful but technically concentrated.

Strengths

The patent combined several formulation limitations that could distinguish a specific commercial cream:

A defined long-chain alcohol class;
Sugar-ester surfactants;
Mineral oil;
Specified co-solvents;
Stability at elevated temperature;
Freeze-thaw stability;
Therapeutic-use limitations; and
Detailed concentration ranges.

Claims 16 and 18 could have been useful against a product closely matching the recited formulation. The stability limitation could also have created a factual barrier because infringement might require analytical testing rather than ingredient comparison alone.

Weaknesses

The estate had several limitations:

It did not claim docosanol itself.
It did not cover every docosanol topical carrier.
It depended heavily on particular excipients.
Claims 1 and 4 included demanding stability limitations.
Claim 20 was broader but required a pain-treatment indication and a physiologically compatible carrier.
The patent's expiration date arrived before the current period of widespread generic competition.
No biosimilar barrier existed.

The patent was strongest against close formulation copies and weakest against products using different carriers, different surfactants, or different active concentrations outside the relevant ranges.

What generic launch scenarios exist after expiration?

Three principal launch scenarios apply.

Direct docosanol 10% cream competition

A manufacturer can sell a product matching the general commercial profile of Abreva, subject to FDA requirements. The expired patent no longer blocks the formulation merely because it contains 10% docosanol.

Formulation design-around

A competitor may use:

A non-sugar-ester emulsifier;
A different oil phase;
A different co-solvent system;
A gel, ointment, lotion, or film rather than the claimed cream;
A different C20-C28 alcohol concentration; or
A different stability profile.

A design-around is commercially less necessary after expiration but may remain relevant to avoid later patents or proprietary manufacturing processes.

Private-label and retailer entry

Private-label products can compete through retailer distribution and lower pricing. The principal barriers are formulation scale, preservative and microbial-control performance, packaging, stability data, and retail placement.

What manufacturing and IP barriers remain?

The expired patent did not eliminate all barriers to entry. Current barriers may include:

Sourcing pharmaceutical-grade n-docosanol;
Controlling particle size and dispersion;
Achieving uniform active distribution;
Maintaining emulsion stability;
Meeting microbial limits;
Selecting compatible packaging;
Establishing shelf life;
Manufacturing under current good manufacturing practice requirements; and
Supporting FDA-compliant labeling and quality documentation.

These are operational and regulatory barriers, not continuing exclusivity rights under Patent 5,534,554.

How does the patent compare with the commercial Abreva product?

The claims cover a broader technical space than a single 10% n-docosanol product.

Issue	Patent scope	Typical Abreva-type product
Active	C20-C28 alcohols in many claims; n-docosanol in others	n-Docosanol
Concentration	Approximately above 5%; some claims 5%-20%	Commonly 10%
Dosage form	Topical cream	Topical cream
Indication	Viral infection, inflammation, pain	Cold sores and fever blisters
Excipients	Sugar esters, mineral oil, specified co-solvents in key claims	Product-specific formulation
Stability	Required in claims 1 and 4, not uniformly across all claims	Commercial shelf-life testing required
Current patent status	Expired	No protection from this patent

A product may resemble Abreva commercially without practicing every limitation of the patent. Conversely, a formulation may fall within the historical claim scope even if it is not marketed for cold sores, depending on the applicable composition claim and the product's ingredients.

Key Takeaways

U.S. Patent 5,534,554 covers stabilized topical creams and treatment methods using C20-C28 long-chain aliphatic alcohols, especially n-docosanol.
The most commercially relevant ingredients are n-docosanol, sucrose esters, mineral oil, water, and specified co-solvents.
Claims 1 and 4 require elevated-temperature and freeze-thaw stability.
Claims 16 and 18 contain the most specific Abreva-type formulation ranges.
Claim 20 is the broadest independent claim because it covers a physiologically compatible carrier and a C20-C28 alcohol at 5%-25%.
The patent expired on January 26, 2013.
There is no current biosimilar issue because docosanol is a small molecule.
Current competition is driven by generic formulation capability, FDA compliance, manufacturing quality, retail distribution, and brand recognition.
Any current exclusivity analysis must examine later-filed patents, trademarks, trade secrets, and regulatory records rather than relying on Patent 5,534,554.

FAQs

Is docosanol itself patented in the United States?

No. U.S. Patent 5,534,554 claimed specified topical compositions and treatment methods. It did not claim n-docosanol as a standalone chemical compound.

Can a company sell a 10% docosanol cream after the patent expired?

Yes, provided the product satisfies applicable FDA requirements and does not infringe a separate unexpired patent or violate another enforceable right.

Does the patent cover docosanol ointments and gels?

Not automatically. The claims are directed primarily to creams or to compositions in a physiologically compatible carrier. A gel or ointment would require element-by-element analysis against the applicable claim.

Is an Abreva generic required to use the same sucrose ester?

No. The expired patent cannot impose that requirement. A competitor may select a different excipient system, subject to FDA product-quality and equivalence requirements.

Does patent expiration eliminate all barriers to generic docosanol entry?

No. Manufacturing validation, stability, microbial control, packaging, FDA compliance, labeling, and commercial distribution remain practical barriers even after patent expiry.

References

United States Patent and Trademark Office. (1996). U.S. Patent No. 5,534,554, Stable compositions containing long chain aliphatic alcohols.
U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations: Orange Book.
U.S. Food and Drug Administration. (2000). Abreva cream, docosanol 10%: FDA approval and product labeling materials.
Haleon plc. (2024). Annual report and consumer healthcare product portfolio disclosures.

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Austria	383848	⤷ Start Trial
Austria	399004	⤷ Start Trial
Australia	693476	⤷ Start Trial
>Country	>Patent Number	>Estimated Expiration	>Supplementary Protection Certificate	>SPC Country	>SPC Expiration

Details for Patent: 5,534,554

Summary for Patent: 5,534,554