List of Excipients in Branded Drug DANAZOL

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Generic Drugs Containing DANAZOL

Company	Ingredient	NDC	Excipient
Lannett Company Inc	danazol	0527-1392	ALCOHOL
Lannett Company Inc	danazol	0527-1392	ALUMINUM OXIDE
Lannett Company Inc	danazol	0527-1392	ANHYDROUS LACTOSE
Lannett Company Inc	danazol	0527-1392	BUTYL ALCOHOL
Lannett Company Inc	danazol	0527-1392	D&C YELLOW NO. 10
Lannett Company Inc	danazol	0527-1392	FD&C BLUE NO. 1
Lannett Company Inc	danazol	0527-1392	FD&C BLUE NO. 2

What are the Most Frequently-Used Excipients in DANAZOL?

# Of NDCs	Excipient
4	ALCOHOL
5	ALUMINUM OXIDE
4	ANHYDROUS LACTOSE
4	BUTYL ALCOHOL
2	D&C RED NO. 28
6	D&C YELLOW NO. 10
1	D&C YELLOW NO. 10 ALUMINUM LAKE

Danazol Excipient Strategy and Commercial Opportunities

Last updated: October 21, 2026

Danazol’s main formulation problem is poor aqueous solubility combined with dose-dependent androgenic toxicity. The strongest commercial opportunity is not a new excipient alone. It is a formulation that improves exposure consistency, permits lower dosing, reduces food effects, or creates a differentiated presentation for endometriosis and hereditary angioedema (HAE).

The established product is an oral capsule, generally supplied in 50 mg, 100 mg, and 200 mg strengths. Danazol is a synthetic steroid with limited solubility and substantial safety restrictions, including virilization, hepatic effects, lipid changes, and contraindication during pregnancy. Any excipient strategy must therefore support predictable bioavailability without materially increasing peak exposure.

What is the current regulatory and commercial status of danazol?

Danazol is an established generic active pharmaceutical ingredient rather than a newly protected pharmaceutical asset. In the United States, historical Danocrine products were approved for endometriosis, fibrocystic breast disease, and prevention of attacks of HAE. Generic danazol capsules remain the relevant commercial dosage form in public FDA labeling records. [1,2]

Attribute	Danazol position
Active ingredient	Danazol
Pharmacologic class	Synthetic androgen; gonadotropin suppressor
Established dosage form	Immediate-release oral capsule
Common strengths	50 mg, 100 mg, 200 mg
Key indications	Endometriosis, HAE prophylaxis, fibrocystic breast disease
Primary formulation issue	Low aqueous solubility and variable oral absorption
Major safety constraints	Androgenic effects, hepatotoxicity, lipid changes, fetal virilization
Main commercial competitors	Modern HAE prophylaxis and acute therapies; hormonal and surgical treatments for endometriosis
Patent profile	Mature product with limited apparent value from basic composition-of-matter protection
Main differentiation route	Bioavailability control, lower-dose delivery, adherence, and geographic access

Danazol has no biosimilar issue because it is a chemically synthesized small molecule. Competition comes from generic manufacturers, alternative hormonal therapies, and newer HAE products rather than from biosimilar developers.

What excipients are most suitable for danazol capsules?

The preferred excipient platform depends on whether the product objective is a conventional generic, an improved immediate-release formulation, or a new delivery system.

Formulation objective	Suitable excipient classes	Commercial rationale	Principal risks
Conventional generic capsule	Lactose, microcrystalline cellulose, starch, colloidal silicon dioxide, magnesium stearate	Low-cost, familiar manufacturing process	Limited differentiation; possible dissolution variability
Improved wetting and dissolution	Polysorbates, sodium lauryl sulfate, poloxamers, crospovidone, croscarmellose sodium	May improve wetting and disintegration	Peroxide sensitivity, tolerability, regulatory justification
Lipid-based delivery	Medium-chain triglycerides, long-chain glycerides, mono- and diglycerides, lecithin, polysorbates	Can increase solubilization and reduce dissolution dependence	Oxidation, capsule compatibility, food-effect uncertainty
Self-emulsifying system	Oil, surfactant, and cosurfactant combinations	Potentially improves oral exposure and dose consistency	High surfactant load, precipitation after dilution
Amorphous solid dispersion	Hypromellose, hypromellose acetate succinate, povidone, copovidone	Can raise apparent solubility and sustain supersaturation	Physical instability, moisture sensitivity, scale-up complexity
Nanocrystal or nanosuspension	Stabilizers such as poloxamers, polysorbates, or povidone	Increases surface area and dissolution rate	Particle-size control, aggregation, manufacturing cost
Modified release	Hydrophilic polymers, ethylcellulose, lipid matrices	May reduce peak exposure and dosing frequency	Less suitable if rapid or predictable absorption is required
Patient-friendly dosage form	Low-mass capsule fill, orally disintegrating tablet, multiparticulate system	May improve swallowing and adherence	Taste masking, dose uniformity, stability

A conventional capsule should use excipients with established oral use and strong compendial support. The simplest platform is a micronized or finely milled danazol blend with a filler, disintegrant, glidant, and lubricant. This approach minimizes regulatory risk but is unlikely to create meaningful commercial exclusivity.

For a differentiated product, lipid-based or amorphous-dispersion technology is more defensible. Danazol’s lipophilic steroid structure makes lipid solubilization technically plausible, but the formulation must be tested for precipitation during gastrointestinal dilution and for food-related changes in exposure.

How does danazol’s physicochemical profile affect excipient selection?

Danazol has a steroidal structure and low water solubility. Poor dissolution can make systemic exposure dependent on particle size, intestinal conditions, and food intake. The formulation objective is to increase the amount of dissolved drug available for absorption while avoiding an excessive increase in peak plasma concentration.

Three properties drive the excipient strategy:

1. Low aqueous solubility favors particle engineering, surfactants, lipid vehicles, or amorphous forms.
2. High lipophilicity supports lipid-based solubilization but creates precipitation and food-effect risks.
3. Androgenic toxicity makes uncontrolled exposure increases commercially unattractive.

A formulation that doubles exposure may fail clinically if it also increases virilization, liver toxicity, or lipid abnormalities. A commercially useful product should target exposure consistency and dose reduction rather than maximum bioavailability.

What formulation patents could protect an improved danazol product?

A new danazol product would most likely rely on formulation, process, or method-of-use claims rather than a new active-ingredient patent.

Potential claim categories include:

Amorphous danazol compositions

Claims could cover:

• Danazol dispersed in a specific polymer matrix.
• Defined drug-loading ranges.
• A specified amorphous fraction.
• Dissolution performance at a defined pH.
• Physical stability after accelerated storage.
• Reduced dose relative to a conventional capsule.

The strongest claims would link composition to measurable performance, such as improved dissolution, reduced variability, or equivalent exposure at a lower dose.

Lipid and self-emulsifying formulations

Possible claims could cover:

• Specific oil-surfactant ratios.
• A self-emulsifying or self-microemulsifying system.
• Particle-size distribution after aqueous dispersion.
• Prevention of danazol precipitation.
• A hard capsule containing a liquid or semisolid fill.

These claims face design-around risk because competitors may substitute oils, surfactants, or cosolvents.

Nanocrystal and particle-engineered products

Claims could cover:

• A defined danazol particle-size range.
• Stabilizer identity and concentration.
• Redispersibility or dissolution limits.
• A manufacturing process using wet milling, precipitation, or high-pressure homogenization.

Process claims may be useful where the finished composition is difficult to distinguish analytically, but enforcement can be difficult if manufacturing occurs outside the relevant jurisdiction.

Method-of-use claims

Potential uses include:

• Lower-dose HAE prophylaxis.
• Reduced androgenic adverse effects.
• Improved treatment of endometriosis.
• Use in patients unable to tolerate conventional danazol capsules.
• A dosing regimen linked to improved exposure consistency.

Method-of-use protection would face substantial validity and infringement challenges because danazol’s indications and therapeutic uses are longstanding.

When does danazol lose exclusivity?

Danazol’s core product exclusivity has already expired in the major pharmaceutical markets. The relevant commercial question is whether a new formulation can obtain regulatory exclusivity or patent protection.

Protection type	Danazol position
Composition-of-matter patent	Expired or commercially irrelevant for the established molecule
Original indication patents	Expired or unlikely to block generic supply
Generic entry	Established
New formulation patent	Potentially available if technically novel and non-obvious
New method-of-use patent	Potentially available but vulnerable to prior-art challenges
Orphan exclusivity	Not inherent to danazol; requires a qualifying new product and indication
Pediatric exclusivity	Not a standing feature of the existing product
Biosimilar exclusivity	Not applicable

FDA approval of a new danazol formulation would not automatically block generic conventional capsules. The new product would need distinct clinical, pharmaceutical, or commercial value.

What is the Orange Book status of danazol?

The Orange Book identifies approved drug products and certain relevant patent and exclusivity information. Danazol’s established generic products are not protected by a current composition-of-matter barrier comparable to a recently launched small molecule. [3]

A new sponsor seeking approval would likely evaluate one of three pathways:

• An abbreviated new drug application for a therapeutically equivalent conventional capsule.
• A 505(b)(2) application for a reformulated or altered-release product.
• A full or hybrid development program if the new formulation makes clinically meaningful claims that cannot be supported through conventional equivalence studies.

A 505(b)(2) strategy is the most commercially relevant route for an improved danazol formulation. It may allow reliance on existing danazol safety and efficacy data while requiring new studies for pharmacokinetics, food effect, dose proportionality, safety, and possibly clinical benefit.

Which companies are challenging danazol’s market?

The market is fragmented rather than dominated by a single generic challenger. Generic drug companies can supply conventional danazol capsules, while branded competitors increasingly address the same conditions through different mechanisms.

HAE competition

Danazol competes with:

• C1 esterase inhibitor products.
• Lanadelumab.
• Berotralstat.
• On-demand icatibant.
• Plasma-derived and recombinant acute therapies.
• Newer oral or targeted prophylactic approaches where available.

These products generally offer better tolerability, more targeted mechanisms, or more convenient prophylaxis than long-term androgen therapy. Danazol remains commercially relevant where cost, availability, or treatment familiarity outweigh those disadvantages.

Endometriosis competition

Danazol competes with:

• Combined hormonal contraceptives.
• Progestins.
• Gonadotropin-releasing hormone agonists and antagonists.
• Aromatase inhibitors.
• Surgery.
• Other hormonal suppression strategies.

In endometriosis, danazol’s androgenic adverse effects reduce its attractiveness relative to newer options. A lower-exposure formulation could improve tolerability, but the clinical development burden would be substantial.

What excipient strategy offers the best commercial opportunity?

The strongest opportunity is a low-dose, exposure-controlled oral product rather than a high-bioavailability product.

Opportunity 1: Lower-dose HAE prophylaxis

A formulation that delivers predictable exposure at a lower danazol dose could target patients who cannot access or afford modern HAE prophylaxis. Development requirements would include:

• Pharmacokinetic comparison with conventional danazol.
• Assessment of attack frequency.
• Liver-function monitoring.
• Lipid monitoring.
• Androgenic adverse-event evaluation.
• Long-term safety data.

The commercial opportunity is greatest in price-sensitive markets, but reimbursement and guideline adoption would remain significant barriers.

Opportunity 2: Food-effect reduction

A formulation that minimizes the difference between fed and fasted exposure could improve treatment reliability. This could be achieved through an amorphous dispersion, nanocrystal, or self-emulsifying system. Food-effect reduction is a clear technical target because variability can lead to underexposure or toxicity.

Opportunity 3: Regional generic-plus products

A manufacturer could develop a robust, low-cost capsule using:

• Micronized danazol.
• A high-performance disintegrant.
• A wetting agent at a low concentration.
• Moisture-protective packaging.
• A simplified manufacturing process compatible with emerging-market facilities.

This product would not necessarily justify broad patent protection, but it could compete through supply reliability, lower cost, and regulatory registration in markets with limited HAE access.

Opportunity 4: Alternative capsule fill

A liquid-filled or semisolid-filled hard capsule could improve dissolution without requiring a complex tablet process. The formulation must control:

• Leakage.
• Shell plasticization.
• Migration of solvents or surfactants into the capsule shell.
• Oxidation of lipid excipients.
• Long-term precipitation of danazol.

Opportunity 5: Patient-centered lower-strength presentations

A 25 mg or other lower-strength product could support dose titration and reduce tablet or capsule splitting. The opportunity is commercially credible if linked to a lower-dose regimen, not if it merely adds another strength without clinical utility.

What manufacturing and intellectual-property barriers exist?

The manufacturing barrier is moderate for conventional capsules and higher for advanced formulations.

Technology	Manufacturing barrier	IP strength	Regulatory burden
Conventional powder-filled capsule	Low	Low	Low
Micronized capsule	Low to moderate	Low to moderate	Low to moderate
Lipid-filled capsule	Moderate	Moderate	Moderate
Self-emulsifying system	Moderate to high	Moderate	Moderate to high
Amorphous solid dispersion	High	Moderate to high	High
Nanocrystal formulation	High	Moderate	High
Modified-release product	Moderate to high	Moderate	High

The principal technical risks are batch-to-batch dissolution variability, recrystallization, moisture uptake, oxidation, and scale-up of particle-size control. The principal legal risks are obviousness challenges based on known solubility-enhancement techniques and design-around by changing polymer, surfactant, particle-size range, or manufacturing process.

What patent litigation and Paragraph IV risks affect danazol?

Danazol’s mature generic status limits the likelihood that conventional products will generate major Paragraph IV litigation. The more meaningful litigation risk would arise around a newly patented formulation or method of use.

A sponsor launching an improved product should expect potential challenges involving:

• Obviousness based on known steroid solubility technologies.
• Anticipation by prior danazol formulation publications.
• Lack of written description for broad excipient ranges.
• Failure to demonstrate an unexpected clinical or pharmaceutical benefit.
• Non-infringement through substitution of excipients or process conditions.
• Invalidity of method-of-use claims based on established indications.

Settlement agreements are not a central feature of the established danazol market. Any settlement involving a new formulation would require case-specific review of the patent, filing date, ANDA timing, and launch restrictions.

How does danazol compare with competing HAE drugs?

Product class	Main advantage over danazol	Main disadvantage versus danazol
C1 esterase inhibitor	Targeted replacement therapy; established HAE use	Injection or infusion burden; higher cost
Lanadelumab	Long-interval prophylaxis; targeted pathway	High acquisition cost; injection
Berotralstat	Oral prophylaxis; non-androgen mechanism	Cost and gastrointestinal tolerability considerations
Icatibant	Convenient on-demand administration	Does not replace routine prophylaxis for all patients
Danazol	Low cost; oral; established experience	Androgenic toxicity, monitoring, pregnancy risk, long-term tolerability

Danazol’s commercial position is therefore defensive and access-driven. Its value is strongest where modern HAE products are unavailable, unaffordable, or unsuitable.

What regulatory studies are needed for a differentiated danazol product?

A reformulated product would normally require:

• Assay, impurities, and content-uniformity data.
• Comparative dissolution across relevant pH conditions.
• Stability under long-term and accelerated conditions.
• Pharmacokinetic comparison with the reference product.
• Food-effect assessment.
• Dose proportionality if new strengths are introduced.
• Evaluation of liver enzymes, lipids, androgenic effects, and reproductive risks.
• Extractables and leachables studies for lipid-filled or polymer-based systems.
• Demonstration that excipients are acceptable for the intended route and dose.

For a conventional generic, bioequivalence and quality studies may be sufficient. For a 505(b)(2) product claiming improved tolerability, lower dose, or reduced HAE attacks, clinical evidence would likely be required.

Key Takeaways

• Danazol is a mature generic small molecule with no biosimilar issue and limited value from basic molecule patents.
• Its main formulation challenge is low solubility and variable oral exposure.
• Lipid systems, amorphous solid dispersions, nanocrystals, and micronized capsules are the most relevant excipient platforms.
• The best commercial target is predictable exposure at a lower dose, not simply higher bioavailability.
• HAE is the most credible niche because danazol remains an inexpensive oral prophylactic option in access-constrained markets.
• A new formulation would likely use a 505(b)(2) pathway if it claims meaningful pharmaceutical or clinical improvement.
• Patent value would depend on specific composition, particle-size, process, performance, and dosing claims.
• Modern HAE products have a strong clinical and commercial advantage, but danazol retains price and availability advantages.
• Conventional generic competition is established; major Paragraph IV risk is more likely for a newly patented reformulation than for standard capsules.

FAQs

Can lipid excipients make danazol more effective?

They can improve dissolution and absorption consistency, but higher exposure may increase androgenic and hepatic toxicity. The development target should be controlled and reproducible exposure.

Is danazol suitable for an amorphous solid dispersion?

Yes, the low-solubility profile makes an amorphous dispersion technically relevant. The main risks are recrystallization, moisture sensitivity, and scale-up reproducibility.

Can a new danazol capsule receive orphan-drug exclusivity for HAE?

Orphan designation and exclusivity would depend on the specific product, indication, clinical rationale, and regulatory criteria. Danazol’s historical use alone does not create new orphan exclusivity.

Would a danazol formulation patent block existing generic capsules?

Usually not. A formulation patent would need claims broad enough to cover the competing product, and conventional capsules could remain outside the patented formulation.

Is a lower-strength danazol capsule commercially valuable?

It can be valuable if it supports a clinically justified lower-dose regimen, titration, or improved tolerability. A new strength without a differentiated dosing benefit would have limited commercial protection.

References

1. U.S. Food and Drug Administration. (n.d.). Danazol capsule prescribing information. FDA and DailyMed labeling records.

2. National Library of Medicine. (n.d.). Danazol: Drug information and labeling records. DailyMed.

3. U.S. Food and Drug Administration. (n.d.). Approved drug products with therapeutic equivalence evaluations. Orange Book.

4. National Center for Biotechnology Information. (n.d.). PubChem compound summary: Danazol. PubChem.

5. U.S. Food and Drug Administration. (2019). Applications covered by section 505(b)(2). FDA guidance and regulatory materials.