United States Patent 4,522,807: Claim Scope, Patent Term, and Sunscreen Formulation Landscape

U.S. Patent No. 4,522,807 covers oil-in-water sunscreen emulsions containing an octadecene-1/maleic anhydride copolymer used to improve substantivity, or resistance to removal from skin. The principal composition claim requires the simultaneous presence of the copolymer, a sunscreen agent, oil, 40% to 95% water, and a pH of 6 to 10. The patent also claims a method of increasing sunscreen substantivity.

The patent was issued in 1985 and, absent a terminal disclaimer or unusual term adjustment, expired in 2002 under the pre-URAA 17-year-from-issuance term applicable to the patent. It therefore does not create current U.S. patent exclusivity or a present generic-entry barrier. Its commercial relevance is historical and technical rather than blocking.

What does U.S. Patent 4,522,807 protect?

The patent protects a defined class of dermatologically compatible sunscreen emulsions and methods using a particular substantive polymer. The central inventive concept is the use of an octadecene-1/maleic anhydride copolymer in an oil-in-water sunscreen formulation to improve retention on skin.

Claim group	Subject matter	Principal limitations
Claim 1	Composition	0.1%-5% copolymer; molecular weight 4,000-100,000; sunscreen agent; oil; 40%-95% water; pH 6-10
Claims 2-7	Narrower compositions	Lower polymer concentration, narrower molecular weight, molar ratio, melting point
Claim 8	Composition subtype	Anionic emulsion
Claims 9-11	Sunscreen-agent embodiments	Homomenthyl salicylate, octyldimethyl PABA, or octyl methoxycinnamate
Claim 12	Narrower pH	pH 7-9
Claim 13	Method	Increasing substantivity by incorporating the copolymer into an oil-in-water sunscreen emulsion
Claim 14	Method subtype	Specific sunscreen agents, including octyl dimethyl PABA, homomenthyl salicylate, benzophenone-3, and octyl methoxycinnamate

The claims do not cover every sunscreen containing an oil, water, or film-forming polymer. Infringement of claim 1 requires the claimed polymer and the specified composition parameters.

How broad is independent claim 1?

Claim 1 is broad in formulation terms but narrow in polymer identity and numerical ranges. A commercial product would need to satisfy every material limitation of the claim.

Required elements of claim 1

A composition falling within claim 1 must include:

A dermatologically compatible oil-in-water emulsion.
Octadecene-1/maleic anhydride copolymer.
Copolymer concentration of 0.1% to 5%.
Copolymer molecular weight of 4,000 to 100,000.
An effective sunscreening amount of a sunscreening agent.
An oil.
Water at 40% to 95%.
A pH of 6 to 10.

The claim does not specify a single sunscreen agent, oil, emulsifier, preservative, fragrance, antioxidant, or dosage form. That gives it breadth across lotions, creams, milks, and similar topical emulsions, provided the claimed composition architecture is present.

The phrase "effective sunscreening amount" is functional. It does not set a fixed concentration, SPF value, or UVA/UVB performance threshold in the claim. The relevant amount would generally be assessed in view of the formulation, specification, labeling, and technical evidence.

The term "highly substantive" describes the intended or demonstrated performance of the emulsion. Whether it independently limits the claim would depend on the specification and claim construction. The more important objective limitations are the polymer, concentration, water content, pH, oil-in-water structure, and sunscreen component.

What do dependent claims 2 through 12 add?

The dependent claims progressively narrow the composition and provide alternative infringement routes only when their additional limitations are satisfied.

Claim	Added limitation	Practical effect
2	Copolymer concentration of 0.3%-3.0%	Excludes concentrations below 0.3% and above 3.0%
3	Molecular weight about 40,000-60,000	Narrows the broad 4,000-100,000 range
4	Molecular weight about 50,000	Narrowest molecular-weight embodiment
5	Monomer ratio about 1:2 to 2:1	Requires an approximately balanced composition
6	Approximately 1:1 monomer ratio	Further narrows claim 5
7	Melting point of 110°-120°	Adds a physical-property limitation
8	Anionic emulsion	Excludes non-anionic formulations from this dependent claim
9	Homomenthyl salicylate	Covers a formulation using this sunscreen agent
10	Octyldimethyl PABA	Covers a formulation using padimate O-type chemistry
11	Octyl methoxycinnamate	Covers octinoxate-containing embodiments
12	pH of 7-9	Narrows claim 1's pH range of 6-10

Claims 3, 4, 5, 6, and 7 create a technical profile around a roughly 50,000-molecular-weight, approximately equimolar copolymer with a 110°-120° melting range. These limitations may have been useful for identifying the preferred commercial or laboratory polymer, but they substantially narrow the enforceable subject matter relative to claim 1.

What does claim 13 cover?

Claim 13 is an independent method claim. It covers increasing the substantivity of an oil-in-water sunscreen emulsion by incorporating the claimed copolymer into the formulation.

The method requires:

An existing oil-in-water sunscreen emulsion;
Oil;
A sunscreening agent;
40% to 95% water;
0.1% to 5% octadecene-1/maleic anhydride copolymer;
Copolymer molecular weight of 4,000 to 100,000; and
pH of 6 to 10.

The method claim is potentially relevant to formulation manufacturing processes and product development, but it is not a general claim to improving sunscreen substantivity with any film former. The specific octadecene-1/maleic anhydride copolymer remains essential.

Claim 14 narrows claim 13 to four sunscreen-agent categories:

Octyl dimethyl PABA;
Homomenthyl salicylate;
Benzophenone-3, commonly oxybenzone; and
Octyl methoxycinnamate, commonly octinoxate.

The spelling "methoxycinnimate" in the supplied claim text appears to be a typographical variant of "methoxycinnamate." The issued patent record controls the legally operative wording.

What formulation designs would fall outside the claims?

Because claim 1 is a combination claim, omission or alteration of one required element generally avoids literal infringement. Potential design-around categories include:

Design-around	Likely claim impact
Use a different substantive polymer	Avoids the expressly claimed copolymer limitation
Use no octadecene-1/maleic anhydride copolymer	Avoids claims 1-14 literally
Use polymer molecular weight below 4,000 or above 100,000	Outside the express range of claims 1 and 13
Use less than 0.1% or more than 5% copolymer	Outside the express concentration range
Use less than 40% or more than 95% water	Outside the claimed water range
Formulate below pH 6 or above pH 10	Outside the express pH range
Use a water-in-oil system	Avoids the oil-in-water limitation
Use a non-emulsion product	Avoids the emulsion limitation
Use a non-sunscreen topical product	Avoids the sunscreen-agent limitation

The doctrine of equivalents could affect some boundary cases, but the numerical ranges and specific polymer identity would remain important prosecution-history and claim-construction issues. A formulation with a different polymer family would ordinarily present a stronger design-around position than one using the same copolymer at a marginally different concentration.

What patent protection exists for the copolymer itself?

The supplied claims do not claim the octadecene-1/maleic anhydride copolymer as a composition of matter in the abstract. They claim its use in a sunscreen formulation and, in claim 13, its use in a sunscreen-emulsion substantivity method.

That distinction limits the patent's scope. A manufacturer could produce or sell the copolymer for non-sunscreen applications without necessarily practicing these claims. A sunscreen manufacturer using the copolymer would face the relevant claim analysis only if the final formulation satisfied the claimed composition or method limitations.

The patent also does not claim:

A particular manufacturing process for the copolymer;
A specific commercial trade name;
A particular package or delivery device;
A specific SPF or UVA rating;
A particular dosage regimen;
A spray, stick, aerosol, or anhydrous product;
A sunscreen active ingredient outside the claimed formulation context.

When did U.S. Patent 4,522,807 lose exclusivity?

U.S. Patent No. 4,522,807 issued in 1985. Pre-1995 U.S. patents generally received a term of 17 years from issuance, subject to terminal disclaimers and other exceptions. On that basis, the patent term ended approximately 17 years after its issuance date, in 2002. The patent is therefore expired and cannot support a current U.S. patent infringement action based solely on the issued claims. [1][2]

Event	Date or period
Patent issuance	1985
Governing historical term	Generally 17 years from issuance
Approximate expiration	2002
Current enforceability	Expired
Current U.S. exclusivity	None from this patent

The patent's expiration does not eliminate regulatory requirements for sunscreen products. It only removes patent-based exclusivity. Current products still must comply with FDA sunscreen requirements, including active-ingredient, labeling, testing, and manufacturing rules applicable to their regulatory pathway. [3][4]

What is the Orange Book status of U.S. Patent 4,522,807?

The patent is not expected to provide current Orange Book protection for a modern sunscreen product.

The Orange Book is principally associated with approved prescription and certain other FDA-approved drug products. Most topical sunscreen products are regulated under the FDA's OTC sunscreen framework rather than through an NDA tied to this 1985 patent. An expired historical formulation patent does not create a current Orange Book barrier to an OTC sunscreen launch.

The patent also does not create a current Paragraph IV issue. A Paragraph IV certification challenges a listed patent associated with an approved drug application. Because this patent expired more than two decades ago and is not a current exclusivity asset, it would not ordinarily support a present Paragraph IV litigation strategy.

How do the claimed sunscreen agents compare with current FDA regulation?

The patent identifies several sunscreen ingredients that were commercially important in the 1980s:

Claimed ingredient	Common identity or relationship	Regulatory relevance
Homomenthyl salicylate	Homosalate	Subject to current FDA OTC sunscreen regulatory requirements and ongoing safety and monograph conditions
Octyldimethyl PABA	Padimate O	Historical U.S. sunscreen active; current marketing requires compliance with applicable FDA conditions
Benzophenone-3	Oxybenzone	Subject to FDA regulatory conditions, labeling, and safety-data requirements
Octyl methoxycinnamate	Octinoxate	Subject to applicable FDA sunscreen rules and jurisdiction-specific restrictions

FDA sunscreen regulation has evolved substantially since the patent issued. The patent's identification of an ingredient does not establish that a current product may be marketed without further regulatory review. The FDA's OTC sunscreen monograph framework and later administrative orders govern current conditions of use. [3][4]

The patent also does not claim zinc oxide or titanium dioxide, the principal mineral sunscreen actives commonly used in modern formulations. A mineral sunscreen using a different substantive polymer would generally have a substantial technical and legal distance from these claims.

How strong is the patent estate?

As a current commercial asset, the estate is weak because the patent is expired. As a historical formulation patent, claim 1 was reasonably useful because it combined a broad set of formulation variables with a specific polymer identity and broad sunscreen-agent language.

Factor	Assessment
Claim breadth	Moderate for formulations using the named copolymer
Polymer specificity	Narrow and technically limiting
Numerical limitations	Clear but create design-around opportunities
Active-ingredient coverage	Broad in claim 1; specific in claims 9-11 and 14
Method protection	Present through claims 13 and 14
Current enforceability	None because the patent is expired
Orange Book value	No current practical value
Biosimilar relevance	None
Generic-entry risk	No current risk from this patent
Manufacturing barrier	None from the expired claims alone

The estate has no biologic or biosimilar dimension. This is a small-molecule topical formulation patent. The relevant competitive questions concern cosmetic formulation, OTC drug regulation, polymer sourcing, stability, sensory properties, SPF performance, and manufacturing economics.

Which companies are challenging the patent?

No current Paragraph IV challenger, settlement agreement, or active U.S. litigation can be inferred from the claims. Given the patent's expiration, a current challenge would have no commercial purpose as a route to early entry.

The patent record supplied does not establish:

A license agreement;
An assignment or acquisition history;
A consent decree;
A validity challenge;
A patent litigation settlement;
A terminal disclaimer; or
A continuing foreign counterpart with unexpired rights.

Any analysis of related family members or foreign rights must be performed separately from the U.S. claims. U.S. expiration does not automatically establish the status of corresponding European, Japanese, Canadian, or other national patents.

What generic launch risks exist?

There is no patent-based generic launch risk from U.S. Patent 4,522,807. A modern sunscreen manufacturer may use the claimed formulation architecture without facing infringement liability from this patent, assuming no other live patent covers the product.

Current launch risks are more likely to arise from:

Later formulation patents covering alternative film-forming polymers;
Patents on water-resistant or substantivity-enhancing systems;
Encapsulation or delivery technologies;
Photostability systems;
Specific active combinations;
Manufacturing processes;
Packaging and dispensing systems;
Trademark and trade-dress rights; and
FDA compliance.

The expired patent may still appear in prior-art searches. Its disclosure could be relevant to novelty or obviousness analysis for later claims involving substantive sunscreen emulsions, particularly where a later patent uses similar copolymer chemistry and formulation ranges.

What licensing or commercial value remains?

Direct licensing value from the U.S. patent is effectively zero because the claims are expired. The technical disclosure may retain value as prior art, formulation know-how, or a historical reference for polymer-based water resistance.

A company could still have commercial leverage from separate assets not covered by this patent, including:

Proprietary polymer grades;
Supplier exclusivity;
Manufacturing specifications;
Stability data;
Regulatory files;
Consumer sensory data;
Brand rights; and
Later, unexpired formulation patents.

Those assets would need to be analyzed independently. They are not established by Patent 4,522,807.

Key Takeaways

U.S. Patent 4,522,807 covers sunscreen oil-in-water emulsions using 0.1% to 5% octadecene-1/maleic anhydride copolymer.
Claim 1 requires the copolymer, sunscreen agent, oil, 40% to 95% water, and pH 6 to 10.
Claims 2-12 narrow concentration, molecular weight, monomer ratio, melting point, emulsion charge, sunscreen active, and pH.
Claims 13 and 14 cover methods of increasing sunscreen substantivity with the same copolymer.
The patent expired approximately in 2002 under the applicable pre-URAA patent term.
It creates no current U.S. patent exclusivity, Orange Book barrier, or Paragraph IV risk.
The claims do not cover the copolymer in the abstract or all sunscreen film-forming systems.
Current commercial risk would arise from later patents, FDA requirements, manufacturing know-how, and regulatory conditions rather than this expired patent.

FAQs

Does Patent 4,522,807 cover all water-resistant sunscreen lotions?

No. It covers only formulations containing the specified octadecene-1/maleic anhydride copolymer and satisfying the claim requirements for water, pH, oil-in-water structure, sunscreen agent, concentration, and molecular weight.

Can a company use octinoxate with a different film-forming polymer?

Yes, Patent 4,522,807 does not claim every octinoxate formulation. A different polymer may avoid the patent's literal copolymer limitation, although later patents must be reviewed separately.

Does the patent cover sunscreen sprays or sticks?

Not necessarily. The claims require an oil-in-water emulsion. An anhydrous stick, aerosol, or non-emulsion product would generally fall outside that structural limitation.

Is homosalate protected by this patent today?

No. The patent's homomenthyl-salicylate embodiment is expired and does not create current exclusivity for homosalate sunscreen products.

Could the patent still be cited against a later sunscreen patent?

Yes. An expired patent can remain relevant as prior art in evaluating novelty, obviousness, written description, or enablement of later patent claims.

References

U.S. Patent No. 4,522,807. (1985). Sunscreen compositions. United States Patent and Trademark Office.
United States Patent and Trademark Office. (n.d.). Patent term calculator and patent term provisions. https://www.uspto.gov/
U.S. Food and Drug Administration. (2021). Sunscreen drug products for over-the-counter human use: Administrative order OTC000008. https://www.fda.gov/
Sunscreen drug products for over-the-counter human use, 21 C.F.R. pt. 352.

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Australia	1071983	⤷ Start Trial
Australia	554643	⤷ Start Trial
Brazil	8300337	⤷ Start Trial
Canada	1196577	⤷ Start Trial
European Patent Office	0085334	⤷ Start Trial
Japan	S58128315	⤷ Start Trial
South Africa	8300458	⤷ Start Trial
>Country	>Patent Number	>Estimated Expiration	>Supplementary Protection Certificate	>SPC Country	>SPC Expiration

Details for Patent: 4,522,807

Summary for Patent: 4,522,807