DEMULEN 1/35-21 Drug Patent Profile

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When do Demulen 1/35-21 patents expire, and what generic alternatives are available?

Demulen 1/35-21 is a drug marketed by Gd Searle Llc and is included in one NDA.

The generic ingredient in DEMULEN 1/35-21 is ethinyl estradiol; ethynodiol diacetate. There is one drug master file entry for this compound. Six suppliers are listed for this compound. Additional details are available on the ethinyl estradiol; ethynodiol diacetate profile page.

Summary for DEMULEN 1/35-21

US Patents:	0
Applicants:	1
NDAs:	1
Raw Ingredient (Bulk) Api Vendors:	6
Patent Applications:	56
DailyMed Link:	DEMULEN 1/35-21 at DailyMed

US Patents and Regulatory Information for DEMULEN 1/35-21

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Exclusivity Expiration
Gd Searle Llc	DEMULEN 1/35-21	ethinyl estradiol; ethynodiol diacetate	TABLET;ORAL-21	018168-001	Approved Prior to Jan 1, 1982		DISCN	No	No

Demulen 1/35-21 Market Dynamics, Patent Status, and Financial Trajectory

Last updated: October 1, 2026

Demulen 1/35-21 is a legacy combined oral contraceptive containing ethynodiol diacetate 1 mg and ethinyl estradiol 35 mcg, packaged as 21 active tablets. Its commercial value has largely ended. The product has no meaningful current branded-market position, no identifiable active exclusivity barrier, and no publicly reported standalone revenue. Market demand migrated to generic ethynodiol diacetate/ethinyl estradiol products and to newer oral contraceptive formulations.

What is Demulen 1/35-21?

Demulen 1/35-21 is a monophasic combined hormonal contraceptive. Each active tablet contains:

Attribute	Product detail
Brand	Demulen 1/35-21
Active ingredients	Ethynodiol diacetate 1 mg and ethinyl estradiol 35 mcg
Dosage form	Oral tablet
Pack configuration	21 active tablets
Therapeutic category	Combined oral contraceptive
Original sponsor	G.D. Searle & Co.
Later corporate ownership	Pfizer acquired Searle in 2003
Regulatory pathway	Abbreviated new drug application and legacy NDA ecosystem
Current commercial position	Legacy or discontinued branded product

Demulen belongs to an older generation of oral contraceptives using a relatively high estrogen dose compared with many later products. Lower-dose ethinyl estradiol products and formulations using newer progestins reduced the product’s competitive relevance over time.

The "1/35" designation refers to 1 mg of ethynodiol diacetate and 35 mcg of ethinyl estradiol. The "21" designation refers to the number of hormone-containing tablets in the cycle pack.

When did Demulen 1/35-21 lose exclusivity?

Demulen 1/35-21 lost practical market exclusivity decades ago. Its commercial protection was based primarily on legacy formulation and brand recognition rather than a currently enforceable patent estate.

For an older oral contraceptive, the relevant exclusivity layers were:

1. Original product patents, if any.
2. FDA approval exclusivity associated with the original application.
3. Trademark protection for the Demulen name.
4. Prescriber and patient familiarity.
5. Manufacturing scale and distribution.

The FDA’s Orange Book framework does not treat an old brand name as a continuing barrier to generic approval. Once applicable patents and regulatory exclusivity expired, generic manufacturers could compete through abbreviated new drug applications.

No current market data indicate that Demulen 1/35-21 retains FDA exclusivity or an active patent-based monopoly. The product is best analyzed as an off-patent legacy contraceptive rather than as an actively protected branded medicine.

What patents protect Demulen 1/35-21?

No active patent protection appears to define the current commercial position of Demulen 1/35-21. The product’s underlying active ingredients and basic oral-tablet combination are longstanding technologies.

Patent estate

Patent category	Current commercial relevance
Active-ingredient patents	Expired or commercially irrelevant
Original formulation patents	No known active barrier supporting current branded exclusivity
Method-of-use patents	No known active patent controlling routine contraception use
Manufacturing patents	Any legacy claims would not prevent ordinary generic competition unless independently valid and enforceable
Device or delivery-system patents	Not applicable to the 21-tablet oral pack
Orange Book-listed patents	No current patent position appears to support an exclusive branded market

A patent search must distinguish between historical patents and enforceable rights. Patent records may show expired composition, formulation, or process patents associated with contraceptive steroids, but those records do not establish current commercial exclusivity.

Demulen 1/35-21 does not have the characteristics of a modern product protected by overlapping formulation, dosing, polymorph, manufacturing, and method-of-use patents. Its active pharmaceutical ingredients are conventional small molecules, and the dosage form is a standard tablet.

What is the Orange Book status of Demulen 1/35-21?

The Orange Book is the primary FDA reference for approved drug products, therapeutic equivalence evaluations, and listed patents. Legacy Demulen products may appear in historical FDA records or discontinued-product listings, but historical appearance does not establish current marketing activity.

The relevant Orange Book conclusions are:

• Demulen is not a current high-value Orange Book product.
• No meaningful patent-based barrier appears to prevent generic substitution.
• Any reference-product status must be evaluated against the specific FDA listing and application history.
• A discontinued branded product can remain relevant to generic approval history even after commercial withdrawal.
• The absence of an active brand does not prevent generic products from being marketed under their own labels.

FDA regulatory records should be read together with DailyMed labeling and the Orange Book’s discontinued-drug information. The approved label identifies the active ingredients, dosage regimen, contraindications, warnings, and thromboembolic-risk information applicable to the product class.[1][2]

Which companies challenged Demulen 1/35-21?

The competitive challenge came from generic oral-contraceptive manufacturers rather than from a major modern Paragraph IV litigation campaign.

Generic competition for the formulation has included products marketed under names such as:

• Zovia 1/35E
• Ethynodiol diacetate and ethinyl estradiol tablets
• Generic equivalents supplied through contract manufacturers and pharmaceutical distributors

Publicly visible market history does not establish a current, economically significant Paragraph IV dispute concerning Demulen 1/35-21. That is consistent with the product’s age and the expiration of the relevant exclusivity period.

Paragraph IV litigation is usually commercially important when a generic applicant challenges an active patent before expiration. Demulen 1/35-21 does not present that profile. Any historical ANDA challenge would have had limited continuing relevance after patent expiration and the subsequent erosion of branded sales.

What generic products compete with Demulen 1/35-21?

The principal substitutes are generic products containing the same active ingredients and strength. These products compete on price, pharmacy availability, payer coverage, and supply reliability.

Direct generic substitutes

Product type	Ingredients	Competitive relationship
Generic ethynodiol diacetate/ethinyl estradiol	1 mg/35 mcg	Direct pharmaceutical equivalent
Zovia 1/35E-type products	1 mg/35 mcg	Brand or authorized-generic-style substitute, depending on market period
Other combined oral contraceptives	Different progestin and estrogen combinations	Therapeutic, but not pharmaceutical, substitutes

The most important commercial distinction is between pharmaceutical equivalence and therapeutic substitution. A generic 1 mg/35 mcg ethynodiol diacetate product directly replicates the Demulen active-ingredient combination. Products containing norethindrone, levonorgestrel, desogestrel, norgestimate, drospirenone, or other progestins compete for the same contraceptive indication but do not duplicate Demulen’s formulation.

How did the market for Demulen 1/35-21 change?

The product’s market trajectory followed the standard pattern for an older branded oral contraceptive:

Initial branded phase

Demulen benefited from physician familiarity, established prescribing habits, and the limited number of oral contraceptive options available when it was introduced. Brand demand was supported by direct prescribing rather than by differentiated delivery technology.

Generic erosion

Once generic competition became available, price competition reduced the brand’s economic value. Oral contraceptives are particularly exposed to substitution because:

• Tablets are relatively simple to manufacture.
• The active ingredients are well characterized.
• Prescribers have many clinically accepted alternatives.
• Pharmacy benefit managers can shift utilization toward lower-cost products.
• Patients often receive contraceptives through insurance formularies or public programs.

Portfolio displacement

Newer products displaced older combinations through differences in progestin selection, dosing schedules, pack design, tolerability profiles, and marketing. The emergence of 28-day packs, extended-cycle regimens, lower-estrogen formulations, and newer progestins weakened the position of a 21-tablet legacy product.

Commercial withdrawal

The brand’s practical value declined as generic products became available and the manufacturer concentrated resources on products with stronger growth or margin potential. Product withdrawal does not necessarily mean demand disappeared. It means demand was no longer sufficient to justify branded manufacturing, promotion, inventory, and regulatory maintenance.

What is the financial trajectory of Demulen 1/35-21?

No reliable public source reports standalone revenue, gross margin, prescription volume, or product-level profitability for Demulen 1/35-21.

The financial trajectory can be characterized as follows:

Period	Financial profile
Pre-generic period	Branded revenue supported by price premium and physician familiarity
Early generic period	Rapid unit-price erosion and loss of formulary leverage
Mature generic period	Low-margin commodity competition
Post-withdrawal period	Little or no branded revenue; residual value limited to historical approvals and trademarks

Pfizer’s public financial reporting does not identify Demulen 1/35-21 as a separate revenue-generating product. Searle’s historical reporting likewise does not provide a product-level revenue series that would support a defensible standalone valuation.

The economic value of the product therefore shifted from brand ownership to generic manufacturing rights, distribution relationships, and portfolio efficiency. Any remaining sales would likely have been captured by generic manufacturers or distributors rather than by the legacy Demulen brand owner.

What revenue exposure did Pfizer have to Demulen?

Pfizer’s exposure was limited by the product’s age, generic competition, and lack of strategic differentiation. Demulen was not a major driver of Pfizer’s reported revenue in the company’s post-acquisition portfolio.

The product’s financial importance was likely determined by:

• Net price after wholesaler and payer discounts.
• Prescription volume.
• Manufacturing cost per tablet.
• Regulatory-maintenance expense.
• Inventory and supply-chain costs.
• Cannibalization by other contraceptive products.
• The cost of maintaining a low-volume legacy brand.

Because Pfizer did not separately disclose Demulen revenue, the product cannot be used as a standalone indicator of Pfizer’s women’s-health performance. It is more appropriately classified as a legacy asset with declining or negligible revenue contribution.

What FDA regulatory issues affect Demulen 1/35-21?

The main regulatory issues are those applicable to combined oral contraceptives:

• Venous and arterial thromboembolic risk.
• Contraindications involving smoking and age.
• Hypertension and cardiovascular disease.
• Migraine with aura.
• Postpartum use and breastfeeding considerations.
• Drug interactions affecting contraceptive effectiveness.
• Patient adherence to the 21-day active-tablet schedule.

The 35 mcg ethinyl estradiol dose is higher than the estrogen dose used in many newer oral contraceptives. Estrogen dose is one factor in the overall risk-benefit assessment, although risk also depends on patient characteristics and the progestin component.

The product’s regulatory status should not be confused with current clinical preference. FDA approval of a legacy formulation does not mean the formulation remains commercially active or preferred in current prescribing practice.

What manufacturing and intellectual-property barriers remain?

Manufacturing barriers are low relative to those for biologics, complex injectables, or modified-release products.

Manufacturing profile

Demulen 1/35-21 requires:

• Sourcing of two established steroidal active ingredients.
• Low-dose content uniformity control.
• Tablet compression and coating.
• Stability testing.
• Packaging into a 21-tablet cycle pack.
• Compliance with current good manufacturing practice requirements.

The principal technical risk is dose uniformity because both hormones are present at low quantities. That issue is manageable through validated blending, granulation, analytical testing, and process controls.

There is no biologic comparability issue, no biosimilar pathway, and no complex delivery device. Manufacturing know-how can support quality and supply reliability, but it is unlikely to create durable market exclusivity.

Is there biosimilar risk for Demulen 1/35-21?

No. Demulen 1/35-21 is a synthetic small-molecule oral tablet, not a biologic. Biosimilar regulation does not apply.

The relevant competitive risks are:

• ANDA-based generic entry.
• Price compression.
• Product discontinuation.
• Supply interruptions.
• Substitution by newer combined oral contraceptives.
• Payer preference for lower-cost alternatives.

What litigation and settlement agreements affect Demulen?

No current high-value patent litigation or settlement structure is known to control the market for Demulen 1/35-21. The product’s litigation risk is materially lower than that of recently launched branded medicines with active composition-of-matter or formulation patents.

Historical litigation, if any, would have limited present commercial significance unless it affected an active generic supplier, manufacturing authorization, or a surviving trademark right. Trademark rights protect branding, not the underlying ability to market an equivalent generic formulation under a different name.

How does Demulen compare with newer contraceptive products?

Factor	Demulen 1/35-21	Newer oral contraceptives
Estrogen	35 mcg ethinyl estradiol	Often lower-dose or alternative estrogen strategies
Progestin	Ethynodiol diacetate	Multiple newer progestin options
Pack	21 active tablets	Commonly 28-day, extended-cycle, or flexible regimens
Patent position	No meaningful active exclusivity	Some products have formulation or method-of-use protection
Market status	Legacy or discontinued brand	Active branded and generic competition
Commercial model	Commodity or historical product	Differentiated branding, formulation, and payer strategy
Biosimilar exposure	None	None for oral small molecules

Demulen’s main weakness is not lack of clinical utility. It is lack of commercial differentiation. In a crowded contraceptive market, an old 21-tablet formulation has limited ability to sustain a price premium.

What generic launch scenarios exist?

The likely launch scenarios are limited:

1. Direct generic substitution: A manufacturer markets ethynodiol diacetate/ethinyl estradiol tablets at the same strength.
2. Low-price maintenance: Existing suppliers continue marketing the product as a low-margin generic.
3. Supply-constrained market: One or more manufacturers withdraw, leaving intermittent availability.
4. Therapeutic substitution: Patients move to other combined oral contraceptives with different progestins or dosing schedules.
5. No branded relaunch: A Demulen-branded relaunch is commercially unlikely without a new distribution or formulation strategy.

A generic entrant would face limited patent risk but could encounter modest commercial returns because the market is mature and heavily price-sensitive.

What is the geographic coverage of Demulen 1/35-21?

The product’s meaningful commercial history is concentrated in the United States. Equivalent hormonal contraceptive combinations may have been marketed under different brand names and regulatory approvals in other countries, but Demulen-specific rights and branding should not be assumed to extend internationally.

Geographic considerations include:

• Separate national approvals.
• Country-specific trademark rights.
• Different contraceptive formularies.
• Local generic substitution rules.
• Distinct supply and pharmacovigilance obligations.
• Varying market preference for 21-day and 28-day regimens.

A U.S. Demulen patent or trademark record would not establish protection in Europe, Canada, Latin America, or other jurisdictions.

Key Takeaways

• Demulen 1/35-21 contains ethynodiol diacetate 1 mg and ethinyl estradiol 35 mcg.
• The product is a legacy combined oral contraceptive with no meaningful current branded exclusivity.
• Generic competition eliminated the product’s historical price premium.
• No active patent estate appears to control current market access.
• Paragraph IV litigation and settlement risk are not material to the current commercial analysis.
• FDA Orange Book and DailyMed records remain relevant for historical approval and labeling information.
• Demulen is not a biologic and has no biosimilar exposure.
• Manufacturing barriers are manageable, with low formulation complexity relative to modern specialty medicines.
• Pfizer did not publicly report standalone Demulen revenue.
• Current value is concentrated in generic supply, not brand ownership or patent protection.

FAQs About Demulen 1/35-21

Is Demulen 1/35-21 still available?

The branded product has largely disappeared from commercial use, while equivalent generic products may be available depending on supplier and market conditions.

What is the generic name for Demulen 1/35-21?

The generic name is ethynodiol diacetate and ethinyl estradiol tablets, 1 mg/35 mcg.

Is Zovia 1/35E the same as Demulen 1/35-21?

Zovia 1/35E is associated with the same active-ingredient combination and strength. Product equivalence depends on the specific FDA-approved product and therapeutic-equivalence designation.

Does Demulen 1/35-21 have remaining patent protection?

No commercially meaningful active patent protection is apparent for the legacy formulation. Historical patents, if identified, must be evaluated for expiration and claim scope.

Can a company relaunch Demulen 1/35-21?

A company could pursue a branded relaunch subject to FDA and trademark requirements, but the product would face generic competition and limited differentiation. The commercial case would depend on distribution, payer positioning, and supply economics.

References

1. U.S. Food and Drug Administration. (n.d.). Drugs@FDA: FDA-approved drugs. https://www.accessdata.fda.gov/scripts/cder/daf/

2. U.S. Food and Drug Administration. (n.d.). Approved drug products with therapeutic equivalence evaluations: Orange Book. https://www.fda.gov/drugs/drug-approvals-and-databases/approved-drug-products-therapeutic-equivalence-evaluations-orange-book

3. National Library of Medicine. (n.d.). DailyMed: Current medication information. https://dailymed.nlm.nih.gov/dailymed/

4. Pfizer Inc. (2003-2023). Annual reports and Form 10-K filings. https://www.pfizer.com/investors/financial-information/annual-reports

5. U.S. Food and Drug Administration. (n.d.). Discontinued drug product list. https://www.fda.gov/drugs/drug-approvals-and-databases/drug-products-discontinued-marketing