ETHYNODIOL DIACETATE AND ETHINYL ESTRADIOL Drug Patent Profile

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Which patents cover Ethynodiol Diacetate And Ethinyl Estradiol, and what generic alternatives are available?

Ethynodiol Diacetate And Ethinyl Estradiol is a drug marketed by Xiromed and is included in two NDAs.

The generic ingredient in ETHYNODIOL DIACETATE AND ETHINYL ESTRADIOL 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 ETHYNODIOL DIACETATE AND ETHINYL ESTRADIOL

US Patents:	0
Applicants:	1
NDAs:	2
Finished Product Suppliers / Packagers:	2
Raw Ingredient (Bulk) Api Vendors:	5
Patent Applications:	56
DailyMed Link:	ETHYNODIOL DIACETATE AND ETHINYL ESTRADIOL at DailyMed

US Patents and Regulatory Information for ETHYNODIOL DIACETATE AND ETHINYL ESTRADIOL

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Exclusivity Expiration
Xiromed	ETHYNODIOL DIACETATE AND ETHINYL ESTRADIOL	ethinyl estradiol; ethynodiol diacetate	TABLET;ORAL-28	204703-001	Jul 28, 2016	AB	RX	No	No
Xiromed	ETHYNODIOL DIACETATE AND ETHINYL ESTRADIOL	ethinyl estradiol; ethynodiol diacetate	TABLET;ORAL-28	204704-001	Feb 9, 2016	AB	RX	No	Yes

Ethynodiol Diacetate and Ethinyl Estradiol Market Dynamics, Patent Status, and Financial Trajectory

Last updated: October 13, 2026

Ethynodiol diacetate and ethinyl estradiol is a mature combined oral contraceptive with limited commercial growth, broad generic substitution, and no meaningful remaining exclusivity moat. The combination is marketed historically under names including Demulen and Zovia, with strengths such as 1 mg/35 mcg and 1 mg/50 mcg. Public companies do not generally report product-level revenue for this combination, so its financial trajectory is best assessed through regulatory status, generic competition, prescription volume, reimbursement, and portfolio strategy rather than disclosed sales.

The product remains commercially relevant as a low-cost oral contraceptive, but it is not a growth asset. Its principal risks are substitution by newer combined oral contraceptives, progestin-only products, long-acting reversible contraceptives, and over-the-counter or prescription alternatives. Its principal commercial advantages are established clinical familiarity, low manufacturing complexity, and inexpensive generic production.

What is ethynodiol diacetate and ethinyl estradiol?

Ethynodiol diacetate and ethinyl estradiol is an oral combined hormonal contraceptive. Ethynodiol diacetate is a progestin, while ethinyl estradiol is an estrogen. The product prevents pregnancy primarily by suppressing ovulation, thickening cervical mucus, and changing the endometrium.

Common historical strengths include:

Product strength	Typical estrogen content	Historical brand association
Ethynodiol diacetate 1 mg / ethinyl estradiol 35 mcg	35 mcg	Zovia 1/35E, Demulen 1/35
Ethynodiol diacetate 1 mg / ethinyl estradiol 50 mcg	50 mcg	Zovia 1/50E, Demulen 1/50

The 50 mcg ethinyl estradiol strength has faced greater clinical and commercial pressure because modern prescribing generally favors lower estrogen exposure where clinically appropriate. FDA labeling identifies contraindications and warnings associated with combined hormonal contraceptives, including thromboembolic risk, smoking in older women, certain migraine patterns, hypertension, and estrogen-sensitive conditions (U.S. Food and Drug Administration [FDA], n.d.-a).

What is the FDA regulatory status of the combination?

The combination is an established prescription oral contraceptive rather than a new molecular entity. Its regulatory history predates the modern generic-drug market, and current products are supported by legacy new drug applications and abbreviated new drug applications.

The FDA-approved product category includes oral tablets with 21 active tablets, 28-day packaging, or equivalent cyclic regimens depending on the product. Product availability has changed over time as brand owners discontinued or transferred products.

DailyMed has historically listed Zovia products containing ethynodiol diacetate and ethinyl estradiol. DailyMed labeling identifies the active ingredients, tablet strengths, dosing schedule, contraindications, warnings, and manufacturer information (National Library of Medicine, n.d.).

The practical regulatory position is:

• The active ingredients are well established.
• The product is not protected by new chemical entity exclusivity.
• Generic approval can proceed through the ANDA pathway when the applicant demonstrates pharmaceutical equivalence and bioequivalence.
• No biosimilar pathway applies because the product is a small-molecule drug, not a biologic.
• Availability can vary by strength, manufacturer, wholesaler inventory, and pharmacy purchasing arrangements.

What is the Orange Book status of ethynodiol diacetate and ethinyl estradiol?

The Orange Book is the relevant FDA source for approved prescription products, therapeutic-equivalence evaluations, patents, and regulatory exclusivity. For a mature combination such as ethynodiol diacetate and ethinyl estradiol, the key commercial question is not whether historical patents existed, but whether any enforceable, unexpired, FDA-listed patent remains attached to a marketed product.

The commercial position is generally consistent with a fully mature generic market:

Exclusivity category	Current commercial significance
New chemical entity exclusivity	Expired or inapplicable
Orphan-drug exclusivity	Not applicable
Pediatric exclusivity	No material current effect identified
First generic exclusivity	Historical only, if granted
Formulation exclusivity	No current market-wide barrier identified
Listed patents	Any relevant historical listings would require product-specific Orange Book verification
Biosimilar exclusivity	Not applicable

The FDA Orange Book should control any transaction, litigation, or launch decision because listings can differ by product, strength, NDA, and date of review (FDA, n.d.-b). The absence of meaningful current exclusivity means that a manufacturer generally competes on supply reliability, price, wholesaler access, and formulary placement.

When does ethynodiol diacetate and ethinyl estradiol lose exclusivity?

The combination lost practical exclusivity many years ago. The active pharmaceutical ingredients and the basic oral-tablet concept are not recent inventions. Any original compound, composition, or method-of-use patents would have expired before the current generic market formed.

A precise patent-expiration analysis requires separating:

1. The original active-ingredient patents.
2. Historical branded-product patents.
3. Packaging or regimen patents.
4. Later formulation patents.
5. Manufacturing-process patents.
6. Product-specific patents listed in the Orange Book.

No current commercial thesis depends on a remaining basic patent for ethynodiol diacetate and ethinyl estradiol. Any newly filed patent would need to cover a specific formulation, delivery system, manufacturing process, or clinical use rather than the basic combination itself. Such a patent would not automatically block conventional generic tablets.

Are there Paragraph IV challenges involving this product?

Paragraph IV litigation has limited present commercial importance for this product because the foundational combination is old and genericized. A Paragraph IV certification is relevant when an ANDA applicant asserts that a listed patent is invalid, unenforceable, or not infringed. The commercial consequences depend on whether an unexpired Orange Book patent is listed against the specific reference product.

For ethynodiol diacetate and ethinyl estradiol:

• Historical ANDA filings may have used Paragraph IV certifications against legacy listed patents.
• Any 30-month stay would have been tied to a specific patent and reference listed drug.
• The most important disputes are likely historical rather than active market events.
• Current generic launch risk is driven more by manufacturing and supply economics than by patent litigation.

The FDA’s Approved Drug Products with Therapeutic Equivalence Evaluations and Federal Register notices remain the principal sources for regulatory exclusivity and patent-related determinations (FDA, n.d.-b; FDA, n.d.-c).

What patents protect the formulation?

The basic immediate-release oral tablet has limited defensibility. A potential formulation estate could include:

• Low-dose tablet composition.
• Stability-enhancing excipients.
• Modified-release delivery.
• Extended-cycle or continuous dosing.
• Packaging designed to reduce missed doses.
• Transdermal, vaginal, implantable, or other delivery systems.
• Manufacturing controls for content uniformity and degradation products.

These categories have different commercial value. A patent on a manufacturing process may increase cost or complicate sourcing without blocking all generic entry. A patent on an alternative delivery system may create a separate product rather than protect conventional tablets.

The 35 mcg product has stronger practical relevance than the 50 mcg product because lower-estrogen prescribing patterns reduce the addressable market for the higher-strength version. Neither strength has a compelling modern formulation moat based on the historical tablet technology alone.

What method-of-use patents apply?

The principal use is contraception. Method-of-use patents covering contraception for this combination would generally be old or commercially weak because the indication is established and generic substitution is permitted for therapeutically equivalent products.

Potential later-use claims could concern:

• Menstrual-cycle management.
• Dysmenorrhea.
• Acne.
• Endometriosis-related symptoms.
• Premenstrual symptoms.
• Extended-cycle dosing.

A method-of-use patent would not necessarily prevent substitution for contraception if the generic label did not carry the patented indication. In practice, such patents are more relevant to labeling strategy and litigation risk than to the basic revenue base.

How many patents cover ethynodiol diacetate and ethinyl estradiol?

The historical patent count is materially higher than the current enforceable patent count. The product has existed for decades, and multiple brands, dosage regimens, and manufacturers may have generated separate historical filings.

A useful commercial classification is:

Patent category	Historical volume	Current blocking value
Active-ingredient patents	Multiple historical filings possible	None expected for the basic combination
Original composition patents	Multiple historical filings possible	Expired
Product-specific formulation patents	Limited and product-dependent	Must be checked by NDA
Method-of-use patents	Limited practical relevance	Usually narrow
Manufacturing patents	Potentially multiple	May affect sourcing, not market entry broadly
Delivery-system patents	Relevant only to non-tablet products	Product-specific

A precise current count cannot be inferred from the ingredient names alone because FDA patent listings are linked to individual reference products and applications.

Which companies compete in the market?

Competition is fragmented. The market includes:

• Legacy brand owners.
• Generic oral-contraceptive manufacturers.
• Contract manufacturers.
• Specialty pharmaceutical companies with women’s-health portfolios.
• Wholesalers and pharmacy suppliers.

Historically associated branded products include Demulen and Zovia. Zovia products have been associated with Mayne Pharma in U.S. labeling records, although commercial ownership, distribution, and availability can change over time (National Library of Medicine, n.d.).

Generic competition is broader than the brand landscape suggests. A product may have several approved ANDAs even when only a subset is actively marketed. Some approvals remain dormant because low prescription volume, low price, or supply-chain complexity makes commercial launch unattractive.

What is the competitive landscape versus newer contraceptives?

Ethynodiol diacetate and ethinyl estradiol competes in a crowded category with meaningful therapeutic substitution.

Competitive category	Commercial effect
Levonorgestrel/ethinyl estradiol	Large generic base and frequent first-line substitution
Norethindrone/ethinyl estradiol	Broad prescribing and generic availability
Drospirenone/ethinyl estradiol	Differentiated clinical positioning, often higher price
Norgestimate/ethinyl estradiol	Established branded and generic alternatives
Progestin-only pills	Relevant where estrogen is contraindicated
Depot medroxyprogesterone	Non-oral alternative
Etonogestrel implant	Long-acting reversible contraceptive competition
Levonorgestrel intrauterine systems	High-duration, device-based substitution
Copper intrauterine devices	Nonhormonal long-acting competition

The product’s relative disadvantage is limited differentiation. Prescribers can choose among multiple combined oral contraceptive formulations with similar dosing convenience. The combination can retain demand where a patient is stable, tolerates it, or receives it at a low out-of-pocket cost, but new starts are vulnerable to formulary and prescribing preferences.

What are the market dynamics and financial trajectory?

The financial trajectory is mature-to-declining rather than expansionary.

Revenue profile

Public revenue disclosures for ethynodiol diacetate and ethinyl estradiol are generally unavailable. Brand owners and generic manufacturers commonly report women’s-health revenue at portfolio level or do not disclose individual products. The product should therefore be valued through scenario-based indicators:

• Prescription volume.
• Average selling price.
• Generic share.
• Active manufacturer count.
• Back-order frequency.
• Reimbursement status.
• Net price after wholesaler and pharmacy discounts.
• Product discontinuations.
• Manufacturing cost.

The expected revenue pattern is:

Period	Market condition	Financial implication
Historical branded period	Limited competition and brand recognition	Higher gross margin
Generic-entry period	Multiple ANDAs and substitution	Sharp price compression
Mature generic period	Low unit price and fragmented supply	Low revenue per prescription
Current portfolio period	Stable residual demand with substitution risk	Flat to declining sales
Future period	Continued migration to alternatives	Further volume erosion unless supply gaps emerge

The product can still generate cash flow when manufacturing cost is low and supply is reliable. It is unlikely to support substantial standalone R&D investment, premium pricing, or a high valuation multiple.

Price and margin dynamics

Generic oral contraceptives have relatively low barriers to production but can have unfavorable economics when:

• Annual demand is small.
• Multiple strengths require separate production campaigns.
• Active ingredients are sourced from a limited number of suppliers.
• Quality testing and batch-release costs are high relative to selling price.
• Retail distribution is fragmented.
• Wholesaler fees consume a large share of gross sales.
• Competitors use temporary discounting to retain formulary access.

A supply interruption can temporarily improve pricing, but such gains are typically short-lived and do not create durable brand value.

What generic launch scenarios exist?

Three launch scenarios are commercially plausible.

Immediate low-price entry

A new generic manufacturer enters with a standard tablet and competes on price. This scenario is difficult to justify unless the applicant has excess capacity, a low-cost API source, or an existing oral-contraceptive distribution platform.

Limited-competition entry

Several approved ANDAs exist, but only one or two products are actively marketed. A new entrant can obtain reasonable volume if it offers dependable supply, even without premium pricing. This is the most attractive scenario for a small portfolio manufacturer.

Supply-constrained market

One or more incumbent manufacturers discontinue the product, creating shortages or intermittent availability. A reliable supplier can capture share temporarily. The opportunity remains operational rather than patent-based, and it can disappear when another manufacturer re-enters.

What manufacturing and intellectual-property barriers exist?

Manufacturing barriers are moderate, while intellectual-property barriers are low.

Key manufacturing requirements include:

• Consistent assay and content uniformity for low-dose hormones.
• Control of cross-contamination in multiproduct facilities.
• Stable tablet compression and coating.
• Validated dissolution performance.
• Control of degradation products.
• Reliable sourcing of ethynodiol diacetate and ethinyl estradiol.
• Compliance with FDA current good manufacturing practice requirements.

Ethinyl estradiol is pharmacologically potent at low doses, which increases the importance of containment and cleaning validation. These requirements can discourage small manufacturers even when patents do not.

The main IP risks concern process know-how, supplier agreements, trademarks, and product-specific regulatory records. They do not arise from a strong, current patent barrier around the active combination.

What patent litigation and settlement agreements affect the product?

No major current patent litigation is central to the commercial outlook of ethynodiol diacetate and ethinyl estradiol based on the mature status of the combination. Historical disputes, if any, would likely have involved legacy brand patents, ANDA certifications, or generic timing.

Settlement agreements would have been most relevant during the transition from branded exclusivity to generic entry. Such agreements could have established an authorized-generic launch, a delayed generic date, or supply arrangements. Their current value is limited unless they affect a still-marketed reference product or a live distribution right.

Is there biosimilar risk?

There is no biosimilar risk because the product is a small-molecule combination, not a biologic. Its relevant competitive risks are:

• Generic substitution.
• Therapeutic substitution.
• Prescription migration.
• Brand discontinuation.
• Supply interruptions.
• Reimbursement changes.

This distinction matters for valuation. Biosimilar markets can preserve manufacturing complexity and pricing differences, while conventional oral contraceptive markets generally experience faster price erosion after generic entry.

What geographic markets are commercially relevant?

The United States is governed by FDA approval, Orange Book therapeutic equivalence, and pharmacy substitution rules. Other markets may use different regulatory classifications and may have different brand histories.

Commercial relevance varies by geography:

• United States: mature generic prescription market.
• Europe: country-specific reimbursement and contraceptive formularies.
• Canada: provincial reimbursement and product-specific availability.
• Latin America: greater retail and branded-generic variation.
• Emerging markets: potentially larger volume but lower unit economics and different regulatory requirements.

A company pursuing international commercialization would need separate registrations, local pharmacovigilance systems, labeling compliance, and distributor agreements. U.S. FDA approval does not confer automatic market access elsewhere.

Key Takeaways

• Ethynodiol diacetate and ethinyl estradiol is a mature combined oral contraceptive with no meaningful new-molecule exclusivity.
• Historical brands include Demulen and Zovia, with 1 mg/35 mcg and 1 mg/50 mcg strengths.
• The product is subject to generic and therapeutic substitution rather than biosimilar competition.
• The 35 mcg strength has stronger practical relevance than the 50 mcg strength because of modern preference for lower estrogen exposure.
• Current commercial value depends on low-cost manufacturing, reliable supply, and distribution access.
• Public product-level revenue is generally unavailable, preventing a precise standalone sales forecast.
• Patent risk is low for conventional tablets; manufacturing, regulatory, and supply-chain execution are more important.
• The financial outlook is stable-to-declining, with temporary upside possible during supply shortages or competitor discontinuations.
• No current patent litigation or settlement structure appears central to the product’s market outlook.
• The asset is more suitable for a low-cost generic portfolio than for premium branded investment.

FAQs

Is ethynodiol diacetate and ethinyl estradiol still commercially available?

Availability depends on strength, manufacturer, wholesaler inventory, and pharmacy sourcing. Historical products remain documented in FDA and DailyMed records, but individual brands can be discontinued or intermittently supplied.

Is Zovia still protected by patents?

The basic Zovia combination is not supported by a meaningful active-ingredient patent moat. Any current patent question must be evaluated against the specific NDA and the FDA Orange Book.

Can a generic manufacturer launch ethynodiol diacetate and ethinyl estradiol?

Yes. A manufacturer generally would pursue an ANDA demonstrating pharmaceutical equivalence and bioequivalence to the applicable reference listed drug, subject to FDA requirements and any product-specific patent certifications.

Why might a manufacturer sell an old contraceptive with low revenue?

A mature product can use existing tablet capacity, established regulatory infrastructure, and low-cost API sourcing. The commercial rationale is stronger when competitors have discontinued the product or supply is constrained.

Is the 50 mcg ethinyl estradiol strength commercially attractive?

Usually less attractive than the 35 mcg strength. The higher estrogen dose has a narrower modern prescribing role and faces stronger clinical and formulary pressure, although residual demand can persist.

References

1. National Library of Medicine. (n.d.). DailyMed: Zovia 1/35E and Zovia 1/50E labeling. U.S. National Library of Medicine. https://dailymed.nlm.nih.gov/

2. U.S. Food and Drug Administration. (n.d.-a). Combined hormonal contraceptives. https://www.fda.gov/

3. U.S. Food and Drug Administration. (n.d.-b). Approved drug products with therapeutic equivalence evaluations: Orange Book. https://www.accessdata.fda.gov/scripts/cder/ob/

4. U.S. Food and Drug Administration. (n.d.-c). Abbreviated new drug application approvals and generic drug regulatory information. https://www.fda.gov/drugs

5. U.S. Food and Drug Administration. (n.d.-d). Current good manufacturing practice requirements for finished pharmaceuticals. https://www.ecfr.gov/**