Details for Patent: 6,787,531

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Summary for Patent: 6,787,531

Title:	Pharmaceutical composition for use as a contraceptive
Abstract:	A pharmaceutical composition comprises, as a first active agent, 6beta,7beta;15beta,16beta-dimethylene-3-oxo-17alpha-pregn-4-ene-21,17-carbolactone (drospirenone) in an amount corresponding to a daily dosage, on administration of the composition, of from about 2 mg to about 4 mg, and, as a second active agent, 17alpha-ethinylestradiol (ethinylestradiol) in an amount corresponding to a daily dosage of from about 0.01 mg to about 0.05 mg, together with one or more pharmaceutically acceptable carriers or excipients.In a specific embodiment, the composition consists of a number of separately packaged and individually removable daily dosage units placed in a packaging unit and intended for oral administration for a period of at least 21 consecutive days, wherein said daily dosage units comprises the combination of drospirenone and ethinylestradiol. The composition may further comprise 7 or less daily dosage units containing no active agent or containing ethinylestradiol alone.
Inventor(s):	Juergen Hilman, Wolfgang Heil, Ralph Lipp, Renate Heithecker, Michael Huempel, Johannes W. Tack
Assignee:	Bayer Pharma AG
Application Number:	US09/654,227
Patent Litigation and PTAB cases:	See patent lawsuits and PTAB cases for patent 6,787,531
Patent Claim Types: see list of patent claims	Composition; Formulation; Compound; Device; Dosage form;

United States Drug Patent 6,787,531: Claim Scope, Expiration, Orange Book Status and Generic Competition

U.S. Patent No. 6,787,531 protected oral contraceptive compositions combining micronized drospirenone with 17α-ethinylestradiol, together with rapid-dissolution specifications and 21-, 22-, 23-, 24-, and 28-day dosing regimens. The patent is associated with Bayer’s Yasmin and related drospirenone/ethinylestradiol products. Its U.S. term expired in 2020, eliminating current blocking value against generic products, although the claims remain relevant to historical Paragraph IV litigation, product design, and patent-estate analysis.[1][2]

What drug products did U.S. Patent 6,787,531 protect?

The patent principally covered:

• Yasmin-type tablets containing approximately 3 mg drospirenone and 0.03 mg ethinylestradiol.
• Yaz-type formulations containing approximately 3 mg drospirenone and 0.02 mg ethinylestradiol.
• Micronized drospirenone particles.
• Micronized or carrier-deposited ethinylestradiol.
• Oral dosage forms that dissolve in the gastric environment.
• Rapid dissolution of drospirenone.
• Blister packs containing active and inactive tablets.
• Extended or modified contraceptive cycles using 21 to 24 active days and 4 to 7 inactive days.
• Continuous-cycle kits involving multiple 28-day cycles followed by a shorter hormone-free interval.

The commercial core is claim 49, which recites approximately 3 mg of micronized drospirenone and approximately 0.03 mg of micronized ethinylestradiol in a tablet, capsule, or pill. Claim 50 covers the corresponding 28-day kit containing 21 active tablets and seven inactive tablets.

These claims map closely to Yasmin’s marketed composition and packaging. Yaz, by contrast, used 3 mg drospirenone and 0.02 mg ethinylestradiol, which falls within the broader ranges in claims 1, 4, 5, 13, 14, 36, 37, 44, and 45.[3]

How many patents cover the invention?

Patent 6,787,531 contains 52 claims in the claim set supplied. The claims fall into six principal groups.

Claim group	Claims	Principal subject matter
Composition ranges	1-5, 19-26, 34-39, 44-49, 51	Drospirenone and ethinylestradiol compositions
Dissolution performance	6-7, 28, 30, 32-33, 38-39	At least 70% dissolution in 30 minutes or 80% in 20 minutes
Cycle packaging	8-18, 29-32	21-, 22-, 23-, 24-, and 28-day kits
Particle-size or surface-area limitation	27, 29, 31, 42	Drospirenone surface area above 10,000 cm²/g
Extended-cycle administration	40-43, 52	Multiple 28-day cycles followed by shorter hormone-free intervals
Commercially specific embodiment	49-50	Approximately 3 mg/0.03 mg tablets and 21-active/7-placebo kits

The patent therefore protected both product attributes and packaging or regimen attributes. It was not limited to a single tablet formulation.

What are the broadest independent claims?

Claim 1: composition claim

Claim 1 requires:

1. About 2 mg to about 4 mg of micronized drospirenone particles.
2. About 0.01 mg to about 0.05 mg of 17α-ethinylestradiol.
3. One or more pharmaceutically acceptable carriers.
4. An oral dosage form exposed to the gastric environment upon dissolution.
5. Effectiveness for oral contraception in a human female.

The practical claim center is a combined drospirenone/ethinylestradiol oral contraceptive. The dose ranges cover many commercial products:

Product profile	Drospirenone	Ethinylestradiol	Within claim 1?
Yasmin	3 mg	0.03 mg	Yes
Yaz	3 mg	0.02 mg	Yes
Generic Yasmin	3 mg	0.03 mg	Yes
Generic Yaz	3 mg	0.02 mg	Yes
Low-dose product with 2 mg/0.01 mg	2 mg	0.01 mg	Yes, subject to other limitations

The “effective for oral contraception” language limits the claimed composition to a contraceptive use context. It does not require a particular clinical efficacy percentage in the claim text.

Claims 8, 10, 11 and 15: kit claims

These claims cover packaging units containing individually removable daily doses. They are directed to the regimen and package architecture rather than only the tablet formulation.

• Claim 8 covers 21 consecutive active days.
• Claim 9 adds seven inactive tablets.
• Claim 10 covers 22, 23, or 24 active days followed by six, five, or four inactive days.
• Claim 11 covers 28-day or multiple-of-28-day schedules.
• Claim 15 covers at least 28 daily units, including at least 21 combination units and one to seven ethinylestradiol-only units without drospirenone.

The kit claims are important because a generic product could use the same active ingredients but attempt to avoid infringement through a different package, schedule, or inactive-tablet configuration.

What formulations are protected by the dissolution claims?

Claims 6 and 7 impose performance requirements on the carrier and dosage form:

• At least 70% of drospirenone must dissolve within 30 minutes.
• Claim 7 raises the requirement to at least 80% within 20 minutes.
• The test uses the USP XXIII Paddle Method.
• The apparatus is USP apparatus 2.
• The test uses 900 mL of water at 37°C, with paddles operating at 50 rpm.

Claims 28, 30, 32, and 33 extend these dissolution limitations to compositions and kits using drospirenone particles that meet the specified test.

The dissolution limitations create a product-performance boundary. A formulation with the required dose and contraceptive combination may fall outside the claim if its drospirenone dissolution is slower than the stated threshold. Conversely, a manufacturer cannot avoid the claim merely by using a different excipient if the finished product satisfies the claimed dissolution result.

Claim 38 requires a carrier effective to promote dissolution, while claim 39 identifies polyvinylpyrrolidone as a narrower carrier. Claims 21-23 list carboxymethylcellulose, hydroxypropyl cellulose, hydroxypropylmethyl cellulose, gelled starch, gelatin, and polyvinylpyrrolidone.

How does the surface-area limitation affect claim scope?

Claim 27 requires drospirenone particles having a surface area of more than 10,000 cm²/g. Claims 29, 31, and 42 apply the same limitation to kits.

This limitation is a particle-engineering restriction. It is narrower than claim 1 because it requires a measurable physical property rather than merely micronization. Surface area can depend on particle size, particle-size distribution, morphology, agglomeration, and measurement method.

The surface-area claims are potentially difficult to assess from a public label alone. Infringement analysis would generally require access to manufacturing specifications, analytical methods, batch data, or discovery testing. A generic sponsor could potentially avoid these claims by using particles with lower surface area, provided the resulting product remains pharmaceutically acceptable and bioequivalent.

What is the commercial significance of claim 49?

Claim 49 is the most commercially targeted composition claim:

Approximately 3 mg micronized drospirenone plus approximately 0.03 mg micronized ethinylestradiol in a tablet, capsule, or pill.

It directly corresponds to the Yasmin strength. The claim is narrower than claim 1 because it specifies approximately 3 mg and 0.03 mg and requires micronized ethinylestradiol.

Claim 50 adds the commercial package:

• 28 consecutive daily units.
• 21 active units.
• Approximately 3 mg drospirenone and 0.03 mg ethinylestradiol in the active units.
• Seven units without drospirenone or ethinylestradiol.

For generic Yasmin products, claims 49 and 50 would have represented the principal historical infringement risk, assuming the generic used the same dose, micronization, dosage form, and 21-active/7-inactive package.

When did U.S. Patent 6,787,531 lose exclusivity?

The patent issued on September 7, 2004. Its U.S. patent term expired in 2020, based on the patent family’s earliest relevant filing date and the applicable 20-year term calculation.[1][2]

Event	Date
Earliest priority filing	1999
U.S. patent grant	September 7, 2004
Patent term	Approximately 20 years from the relevant nonprovisional/PCT filing
U.S. expiration	2020
Current status	Expired; no current exclusionary term

The exact enforceability period must be determined from the USPTO term record, including any patent-term adjustment, terminal disclaimer, or applicable patent-term extension. The patent was no longer an active blocking patent by the time generic drospirenone/ethinylestradiol products became broadly established in the U.S. market.

What was the Orange Book status of U.S. Patent 6,787,531?

Patent 6,787,531 was listed in the FDA Orange Book for Bayer’s drospirenone/ethinylestradiol products, including Yasmin-related products.[2][4]

The listing supported patent certifications for ANDA applicants under Hatch-Waxman:

• Paragraph I: no patent information listed.
• Paragraph II: listed patent had expired.
• Paragraph III: applicant would market after patent expiration.
• Paragraph IV: listed patent was invalid, unenforceable, or not infringed.

During the active patent period, an ANDA applicant relying on the Yasmin reference listed patent could have filed a Paragraph IV certification. The patent holder’s infringement action within 45 days could trigger a 30-month stay of ANDA approval under 21 U.S.C. § 355(j)(5)(B)(iii), subject to statutory exceptions and later litigation outcomes.[5]

After expiration, the patent could no longer support a 30-month stay based on its own term. FDA approval of generic products was therefore governed by the remaining Orange Book patents, regulatory exclusivities, labeling requirements, and any applicable settlement terms.

Which companies challenged the drospirenone/ethinylestradiol patent estate?

The principal competitive pressure came from generic manufacturers pursuing ANDAs for Yasmin- and Yaz-equivalent products. Publicly marketed U.S. competitors have included products associated with Barr Pharmaceuticals, Teva, Watson/Actavis, Glenmark, Lupin, Sandoz, Mylan/Viatris, and other ANDA sponsors.

Historical generic products included:

Reference product	Generic product examples	Typical strength
Yasmin	Ocella and later equivalents	3 mg/0.03 mg
Yaz	Gianvi, Loryna, Nikki and later equivalents	3 mg/0.02 mg
Beyaz-type products	Generic equivalents with levomefolate	3 mg/0.02 mg plus folate

The relevant challenge was product-specific. An ANDA sponsor had to address the patents listed for its selected reference product, not every patent in the broader drospirenone estate.

What patent litigation affected Yasmin and Yaz generics?

The principal historical disputes involved Bayer and generic applicants seeking approval for drospirenone/ethinylestradiol products. Litigation typically focused on:

• Whether the generic formulation used micronized drospirenone.
• Whether its dose and ethinylestradiol strength fell within the claims.
• Whether the generic package reproduced the 21-active/7-inactive regimen.
• Whether the formulation satisfied the claimed dissolution profile.
• Whether separate formulation, treatment-method, or packaging patents remained valid.
• Whether the generic applicant could launch under a Paragraph IV certification.

Public ANDA litigation records and FDA patent listings should be reviewed by product and NDA because the litigation history differed between Yasmin, Yaz, and related products.[2][4][6]

The patent’s expiration means that any historical settlement agreement involving this patent no longer creates a current patent barrier. Settlement provisions can still matter for damages periods, launch dates, supply rights, or admissions, but they do not restore the expired patent term.

Did Bayer license the patent?

The patent is associated with the Schering/Bayer drospirenone contraceptive program. Commercial rights were developed through the Bayer-Schering pharmaceutical business and regional commercialization arrangements. A patent assignment or corporate succession is not the same as a third-party license.

No separate third-party license is required to explain the U.S. commercial position of Yasmin. Bayer’s ownership and commercialization history account for the principal branded-product rights. Regional distribution or co-promotion agreements may have existed, but they do not change the expired status of the U.S. patent.[1][7]

Are biosimilars a risk for this patent?

No. Drospirenone and ethinylestradiol are chemically synthesized small-molecule active ingredients. Products relying on this patent would use the ANDA pathway, not the biosimilar pathway under the Public Health Service Act.

The relevant competitive risks were:

• ANDA generic entry.
• Formulation substitution.
• Alternative package designs.
• Different active/inactive day schedules.
• Non-infringing particle-size or dissolution profiles.
• Combination products adding folate or changing excipients.

How strong was the patent estate?

Strengths

The patent had meaningful historical value because it combined several commercially relevant limitations:

• Exact or near-exact Yasmin dose levels.
• Micronized drospirenone.
• Micronized ethinylestradiol.
• Gastric dissolution.
• Quantified dissolution performance.
• Commercial blister-pack schedules.
• Extended-cycle regimens.

Claims 49 and 50 were particularly relevant to a product matching Yasmin’s 3 mg/0.03 mg formulation and 21-active/7-inactive package.

Weaknesses

The estate also had design-around and validity vulnerabilities:

• Broad numerical ranges could face prior-art and obviousness challenges.
• “About” language creates boundary questions around dose ranges.
• Dissolution claims depend on a specified test protocol and product preparation.
• Surface-area claims require reliable measurement and reproducibility.
• Kit claims can potentially be avoided through different packaging or dosing schedules.
• Functional limitations such as “effective for oral contraception” may raise claim-construction issues.
• Claims 19, 20, 26, and 51 introduce prodrug and ester/ether subject matter that sits awkwardly with the base requirement for drospirenone or ethinylestradiol and may require careful written-description and claim-construction analysis.

The patent was commercially strong during its term but has no present blocking strength because it expired.

What generic launch risks existed?

Before expiration, the principal launch scenarios were:

Generic strategy	Patent exposure
3 mg/0.03 mg tablet with micronized ingredients	High exposure to claims 1 and 49
21 active plus 7 placebo package	High exposure to claims 8, 9, 50 and related claims
3 mg/0.02 mg Yaz-type product	Exposure to broad composition and kit claims
Different placebo count	Potential design-around of selected kit claims
Slower dissolution	Potential avoidance of dissolution claims, subject to bioequivalence
Lower drospirenone surface area	Potential avoidance of claims 27, 29, 31 and 42
Different excipient system	May avoid dependent carrier claims but not necessarily claim 1
Continuous-cycle product	Exposure to claims 40-43 and 52

Today, generic entry risk from this patent is zero as a patent-term matter. Remaining risk must be assessed against other active patents, regulatory exclusivity, trademark rights, labeling restrictions, and product-specific FDA records.

What geographic coverage did the patent provide?

U.S. Patent 6,787,531 provided rights only in the United States. The underlying invention was pursued through an international patent family, with corresponding applications in jurisdictions such as Europe and other national markets. Foreign patents had separate claims, prosecution histories, term dates, supplementary protection certificates, and litigation outcomes.

A U.S. expiration did not automatically terminate foreign rights. Conversely, a foreign patent surviving or receiving supplementary protection did not extend the U.S. patent.

Key Takeaways

• U.S. Patent 6,787,531 covered drospirenone/ethinylestradiol oral contraceptive compositions and packaging regimens.
• The principal commercial embodiment was approximately 3 mg drospirenone and 0.03 mg ethinylestradiol, corresponding to Yasmin.
• Claim 49 targeted the Yasmin-strength composition; claim 50 targeted the 21-active/7-inactive package.
• Claims 6-7, 28, 30, 32, and 33 added rapid-dissolution requirements.
• Claims 27, 29, 31, and 42 added a drospirenone surface-area limitation.
• The patent supported historical Orange Book listings and Paragraph IV disputes.
• It expired in 2020 and no longer blocks generic launch.
• Generic products such as Ocella, Gianvi, Loryna, and Nikki entered through the ANDA pathway.
• Biosimilar analysis is irrelevant because the active ingredients are small molecules.
• Any current freedom-to-operate review must focus on other active patents, FDA listings, trademarks, and labeling rights.

FAQs

What is the main drug associated with U.S. Patent 6,787,531?

The principal branded product is Yasmin, a combined oral contraceptive containing 3 mg drospirenone and 0.03 mg ethinylestradiol.

Does U.S. Patent 6,787,531 cover Yaz?

Its broader composition and kit claims encompass the 3 mg drospirenone/0.02 mg ethinylestradiol profile used by Yaz, although claim coverage depends on all applicable limitations, including micronization, packaging, and dissolution.

Can a generic manufacturer still infringe U.S. Patent 6,787,531?

The patent’s term expired in 2020. A manufacturer cannot face ordinary patent infringement liability for post-expiration commercial activity based solely on this patent.

Is micronized drospirenone required in every claim?

No. Claims 1 and several kit claims require micronized drospirenone, while claims 27, 28, and related claims use surface-area or dissolution limitations. The applicable limitation depends on the asserted claim.

Does a 28-day contraceptive package always infringe the patent?

No. A 28-day package must satisfy all limitations of an asserted claim, including the drospirenone and ethinylestradiol amounts, dosage-form characteristics, active-day structure, and any surface-area or dissolution requirement.

References

1. United States Patent and Trademark Office. (2004). U.S. Patent No. 6,787,531, pharmaceutical compositions containing drospirenone and ethinylestradiol.
2. U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations: Orange Book.
3. Bayer HealthCare Pharmaceuticals Inc. (2012). Yasmin prescribing information. U.S. Food and Drug Administration.
4. U.S. Food and Drug Administration. (2024). Drugs@FDA: Yasmin, Yaz and related drospirenone/ethinylestradiol products.
5. 21 U.S.C. § 355(j)(5)(B)(iii).
6. U.S. District Court and Federal Circuit records concerning ANDA litigation involving Bayer drospirenone/ethinylestradiol products.
7. Bayer AG. (2006). Annual report and pharmaceutical business records concerning the Schering acquisition and women’s healthcare portfolio.

Drugs Protected by US Patent 6,787,531

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Patented / Exclusive Use	Submissiondate

International Family Members for US Patent 6,787,531

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
European Patent Office	1214076		C01214076/01	Switzerland
European Patent Office	1380301		CA 2009 00017	Denmark
European Patent Office	1380301		SPC019/2009	Ireland
European Patent Office	1214076		SZ 49/2008	Austria
European Patent Office	1214076		49/2008	Austria