List of Excipients in Branded Drug MIFEPRISTONE

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Company	Tradename	Ingredient	NDC	Excipient	Potential Generic Entry
Corcept Therapeutics Incorporated	MIFEPRISTONE	mifepristone	76346-654	ALUMINUM OXIDE
Corcept Therapeutics Incorporated	MIFEPRISTONE	mifepristone	76346-654	CELLULOSE, MICROCRYSTALLINE
Corcept Therapeutics Incorporated	MIFEPRISTONE	mifepristone	76346-654	D&C YELLOW NO. 10
Corcept Therapeutics Incorporated	MIFEPRISTONE	mifepristone	76346-654	FD&C YELLOW NO. 6
Corcept Therapeutics Incorporated	MIFEPRISTONE	mifepristone	76346-654	HYDROXYPROPYL CELLULOSE

Generic Drugs Containing MIFEPRISTONE

Company	Ingredient	NDC	Excipient
Actavis Pharma Inc	mifepristone	0591-4390	CELLULOSE, MICROCRYSTALLINE
Actavis Pharma Inc	mifepristone	0591-4390	FD&C BLUE NO. 1
Actavis Pharma Inc	mifepristone	0591-4390	FD&C YELLOW NO. 5 ALUMINUM LAKE
Actavis Pharma Inc	mifepristone	0591-4390	FD&C YELLOW NO. 6
Actavis Pharma Inc	mifepristone	0591-4390	HYDROXYPROPYL CELLULOSE

What are the Most Frequently-Used Excipients in MIFEPRISTONE?

# Of NDCs	Excipient
3	CELLULOSE, MICROCRYSTALLINE
1	FD&C BLUE NO. 1
1	FD&C YELLOW NO. 5 ALUMINUM LAKE
1	FD&C YELLOW NO. 6
1	HYDROXYPROPYL CELLULOSE

Mifepristone Excipient Strategy and Commercial Opportunities

Last updated: October 2, 2026

Mifepristone is a mature small-molecule product with limited opportunity for value creation through basic tablet reformulation. The strongest commercial strategies are differentiated oral delivery, improved stability, pediatric or specialty-use presentations, global access formulations, and excipient systems that support manufacturing under constrained supply conditions. Core composition-of-matter protection has expired, while regulatory controls, manufacturing quality, product-specific labeling, and distribution requirements remain more important barriers than traditional molecule patents.

The principal U.S. products are Mifeprex, a 200 mg mifepristone tablet for medication abortion; generic mifepristone 200 mg tablets, including products approved through the ANDA pathway; and Korlym, a 300 mg tablet for hyperglycemia secondary to endogenous Cushing's syndrome in adults with type 2 diabetes or glucose intolerance who are not candidates for surgery or have failed surgery.[1-4]

What is the commercial role of excipients in mifepristone products?

Excipients determine whether a mifepristone product can meet dissolution, stability, manufacturability, patient-use, and regulatory requirements at commercial scale. They are unlikely to create broad exclusivity by themselves unless combined with a novel dosage form, a clinically meaningful performance advantage, or a difficult-to-design-around delivery system.

Mifepristone is a practically insoluble, lipophilic compound. A conventional immediate-release tablet therefore depends on particle-size control, wetting, disintegration, granulation, lubricant selection, and dissolution performance. The commercial objective is usually not to change systemic exposure dramatically. It is to maintain reliable exposure while reducing manufacturing variability and simplifying administration.

The main formulation objectives are:

Objective	Relevant excipient strategy	Commercial value
Improve dissolution	Wetting agents, optimized disintegrants, particle engineering, solid dispersions	Supports bioequivalence and batch consistency
Improve tablet robustness	Microcrystalline cellulose, povidone, compression optimization	Reduces friability and manufacturing failures
Control disintegration	Sodium starch glycolate, croscarmellose sodium, crospovidone	Supports rapid drug release
Improve stability	Antioxidant control, low-moisture excipients, protective packaging	Extends shelf life and reduces degradation risk
Reduce swallowing burden	Orally disintegrating, mini-tablet, or dispersible formats	Improves use in access-constrained settings
Improve supply resilience	Multiple qualified grades and dual-source excipient strategy	Reduces manufacturing interruption risk
Support global registration	Pharmacopeial, low-cost, widely available excipients	Simplifies country-by-country filing

What excipients are used in approved mifepristone products?

Mifeprex 200 mg tablet

The Mifeprex label identifies a conventional immediate-release tablet platform. Listed inactive ingredients include colloidal silicon dioxide, magnesium stearate, microcrystalline cellulose, povidone, and sodium starch glycolate.[1]

This combination is commercially conventional:

• Microcrystalline cellulose provides bulk and compressibility.
• Povidone functions primarily as a binder.
• Sodium starch glycolate promotes tablet disintegration.
• Colloidal silicon dioxide improves powder flow.
• Magnesium stearate reduces punch and die adhesion.

The formulation is relatively accessible to generic manufacturers. It does not depend on a complex delivery device, a controlled-release matrix, or a proprietary excipient system.

Korlym 300 mg tablet

Korlym uses a separate formulation and strength. Its listed inactive ingredients include colloidal silicon dioxide, croscarmellose sodium, lactose monohydrate, magnesium stearate, microcrystalline cellulose, and povidone.[2]

The presence of lactose and croscarmellose sodium creates a different manufacturing and excipient profile from Mifeprex. The 300 mg strength also reduces the relevance of direct formulation substitution between the two products. Korlym is indicated for a different disease population and is distributed through a controlled commercial model associated with Corcept Therapeutics.

Generic mifepristone

FDA-approved generic mifepristone products must demonstrate pharmaceutical equivalence and bioequivalence to the applicable reference product under the ANDA framework. The exact inactive ingredients can differ, subject to regulatory requirements and labeling restrictions.[3]

Generic manufacturers can create value through:

• lower-cost excipient sourcing;
• improved compression and high-speed tableting;
• reduced tablet weight;
• better moisture control;
• lower friability;
• more reliable dissolution across commercial scale;
• alternative packaging;
• dual-source excipient qualification.

A generic product cannot assume that a different excipient profile will provide a commercial advantage. Any change must preserve bioequivalence, stability, safety, and labeling compliance.

What formulation patents protect mifepristone products?

The principal mifepristone molecule is long off patent. U.S. Patent No. 4,386,085, associated with the early development of mifepristone, expired years ago. Current competitive protection does not primarily depend on the original active pharmaceutical ingredient patent.

Formulation-related protection is more limited. Potential patent categories include:

1. Modified-release tablets or capsules.
2. Orally disintegrating tablets.
3. Buccal or sublingual delivery systems.
4. Amorphous solid dispersions.
5. Nanoparticle or lipid-based formulations.
6. Combination products.
7. Stabilized compositions with defined excipient ratios.
8. Specific methods of improving absorption or reducing variability.
9. Packaging systems that control moisture or light exposure.
10. Manufacturing processes that produce a defined dissolution profile.

A formulation patent must provide more than a routine substitution of one disintegrant or binder for another. The strongest claims would typically require a defined composition, measurable dissolution profile, stability result, pharmacokinetic advantage, or clinical-use benefit.

How strong is the patent estate for mifepristone?

The patent estate for conventional immediate-release mifepristone tablets is weak relative to newer specialty pharmaceuticals. The active ingredient is genericized, the tablet technology is conventional, and several excipients are standard pharmaceutical materials.

A new entrant could obtain meaningful protection if it develops a product with:

• a non-obvious dosage form;
• a clinically relevant reduction in administration burden;
• improved exposure in patients with gastrointestinal limitations;
• a validated low-dose or pediatric application;
• a stable formulation for hot and humid climates;
• a new combination with a distinct therapeutic indication;
• a manufacturing process that is difficult to replicate and supported by patent claims.

A patent covering only a standard blend of microcrystalline cellulose, povidone, magnesium stearate, and a disintegrant would face substantial validity and enforcement risk.

When does mifepristone lose exclusivity?

Mifepristone has already lost core molecular exclusivity in the United States. Mifeprex was approved in 2000 under NDA 020687, and generic mifepristone tablets were approved decades after the original compound patents expired.[1,3]

Korlym has a separate regulatory and commercial history. Its product-specific protection may include patents and regulatory exclusivity tied to the product, indication, formulation, or approved use. Korlym is not interchangeable commercially with Mifeprex because it is marketed for endogenous Cushing's syndrome and supplied through a specialty distribution structure.[2,4]

Product	Sponsor or manufacturer	Strength	Principal indication	Core exclusivity position
Mifeprex	Danco Laboratories	200 mg	Medication abortion	Molecule and conventional tablet technology are mature
Generic mifepristone	Multiple ANDA sponsors	200 mg	Medication abortion	Competes primarily on supply, price, access, and distribution
Korlym	Corcept Therapeutics	300 mg	Cushing's syndrome-associated hyperglycemia	Product-specific patent and regulatory analysis required

Patent expiry dates for any current Korlym listing, formulation patent, or method-of-use patent should be confirmed in the FDA Orange Book and the relevant patent records before a launch or licensing decision.[5]

What is the FDA regulatory status of mifepristone?

Mifeprex is FDA-approved for medication abortion through 70 days of pregnancy when used with misoprostol under the labeled regimen.[1] Generic mifepristone products have been approved through the ANDA pathway.[3]

FDA modified the Mifeprex Risk Evaluation and Mitigation Strategy in 2023. The revised framework removed the in-person dispensing requirement and permits certified pharmacies to dispense mifepristone, subject to the applicable certification and dispensing conditions.[6]

The regulatory environment remains central to commercial planning. A formulation company must evaluate:

• NDA or ANDA pathway;
• reference product selection;
• bioequivalence requirements;
• stability and dissolution methods;
• REMS obligations;
• pharmacy and wholesaler certification;
• state-level distribution restrictions;
• labeling consistency;
• postmarket pharmacovigilance;
• supply continuity and recall management.

What is the Orange Book status of mifepristone?

The FDA Orange Book identifies approved products, patent listings, and exclusivity information for drug products approved under the Federal Food, Drug, and Cosmetic Act.[5] For mifepristone, the key practical distinction is between:

• the older Mifeprex NDA;
• generic 200 mg ANDA products;
• Korlym, which has a different NDA, strength, indication, and commercial strategy.

A Paragraph IV analysis must be conducted product by product. A generic applicant challenging a listed patent would need to assess composition, formulation, method-of-use, and regulatory exclusivity claims. A generic mifepristone applicant may also face REMS implementation and distribution requirements that are operationally significant even when patent barriers are limited.

What Paragraph IV challenges affect mifepristone?

Paragraph IV certification is relevant when an ANDA applicant states that a listed patent is invalid, unenforceable, or will not be infringed by the proposed generic product. The commercial consequences can include:

• patent litigation after notice to the listed patent holder;
• a 30-month stay of approval in applicable circumstances;
• potential 180-day generic exclusivity for the first qualifying Paragraph IV filer;
• launch-at-risk decisions;
• settlement agreements;
• supply and pricing commitments.

For Mifeprex, the core market has moved into a generic competition phase. The more significant Paragraph IV risk is likely to arise from any later-listed formulation, use, or delivery patent rather than the original mifepristone molecule.

For Korlym, the risk profile is more concentrated. A challenger would need to evaluate patent listings covering the 300 mg product, approved use, formulation, and any related commercial protection. The absence of a broad molecule patent does not eliminate product-specific litigation risk.

What excipient strategies create the best commercial opportunities?

1. Orally disintegrating or dispersible mifepristone

An orally disintegrating tablet could reduce the need for water and simplify administration. The formulation would need to balance:

• rapid disintegration;
• acceptable mouthfeel;
• dose uniformity;
• tablet hardness;
• moisture sensitivity;
• taste masking;
• packaging protection.

Mifepristone has a pharmacologically active profile and may present taste challenges. Flavoring, sweeteners, polymeric taste blockers, and coated particles could be evaluated, although each introduces new stability and manufacturing considerations.

This strategy has potential in decentralized care and markets where water access, privacy, or clinic infrastructure is limited. It also creates a stronger basis for differentiated formulation claims than a standard swallowed tablet.

2. Low-cost heat- and humidity-stable tablets

A robust immediate-release tablet designed for tropical climates may have broader commercial value than a sophisticated delivery system. Opportunities include:

• low-moisture excipient grades;
• high-barrier blister packaging;
• desiccant integration;
• optimized granulation;
• reduced hygroscopicity;
• stability-indicating dissolution control.

This approach is particularly relevant to public-sector procurement, global health programs, and countries with weak cold-chain or warehouse infrastructure. Mifepristone does not generally require refrigerated distribution, so the commercial focus is on shelf life under heat and humidity rather than cold-chain compatibility.

3. Fixed-dose or co-packaged regimens

Mifepristone is used with misoprostol in medication abortion. A co-packaged product can reduce dispensing errors and improve regimen adherence. A fixed-dose combination tablet is technically more complex because the two active ingredients have different physicochemical properties, stability profiles, dose requirements, and regulatory histories.

A co-packaged kit may be more practical than a single combined tablet. Commercial differentiation could come from:

• calendarized blister packaging;
• clear administration instructions;
• tamper-evident packaging;
• multilingual labeling;
• adherence-oriented packaging;
• low-cost public-sector presentation.

The intellectual-property position would likely depend more on packaging, labeling, and combination claims than on the standard active ingredients.

4. Improved formulation for Cushing's syndrome

Korlym is administered chronically in a specialty population. Potential formulation strategies include:

• lower tablet burden;
• improved dose flexibility;
• scored or multiple-strength tablets;
• reduced food-effect variability;
• better tolerability through excipient selection;
• specialty adherence packaging.

A lower-strength Korlym presentation could support dose titration and reduce tablet splitting. That opportunity would need to be assessed against clinical demand, manufacturing cost, and the existing product-specific patent estate.

5. Alternative delivery systems

Buccal, sublingual, transdermal, and long-acting systems could create stronger differentiation but carry high development risk. Mifepristone's lipophilicity may support some nonoral approaches, but dose delivery, local irritation, pharmacokinetic variability, and patient acceptability would need to be demonstrated.

Such products would likely require a 505(b)(2) NDA rather than a simple ANDA if they materially change route, dosage form, or exposure. The 505(b)(2) pathway can support reliance on existing safety and efficacy data while requiring new studies for the changed product.[7]

How does mifepristone compare with competing formulation opportunities?

Opportunity	Development complexity	Patent potential	Regulatory pathway	Commercial attractiveness
Conventional generic tablet	Low to moderate	Low	ANDA	High volume, price pressure
Heat-stable tablet	Moderate	Moderate	ANDA or 505(b)(2), depending on change	Strong in global and public-sector markets
Orally disintegrating tablet	Moderate to high	Moderate to strong	505(b)(2) or applicable generic pathway	Differentiated administration
Co-packaged mifepristone-misoprostol kit	Moderate	Moderate	NDA or supplemental pathway	Strong adherence and access rationale
Fixed-dose combination tablet	High	Stronger if novel	505(b)(2) or NDA	Higher technical and regulatory risk
Buccal or sublingual product	High	Strong	505(b)(2) or NDA	Potentially differentiated, uncertain demand
Long-acting formulation	Very high	Strong	NDA	Large technical risk and uncertain market
New Korlym strength	Moderate	Moderate	Supplemental NDA or 505(b)(2)	Specialty-market opportunity

Which companies are positioned in the mifepristone market?

Danco Laboratories is associated with Mifeprex in the United States. GenBioPro has marketed generic mifepristone and has been an important supplier in the U.S. medication-abortion market. Teva has also obtained FDA approval for a generic mifepristone product.[1,3,8]

Corcept Therapeutics markets Korlym for endogenous Cushing's syndrome. Its economics differ from the Mifeprex market because Korlym is a specialty product with chronic use, payer management, patient services, and a higher annual treatment value per patient.[2,4]

The competitive landscape divides into two markets:

• A high-volume, price-sensitive 200 mg medication-abortion market.
• A lower-volume, specialty chronic-treatment market for 300 mg Korlym.

An excipient supplier can pursue both markets through different value propositions. For Mifeprex and generic products, cost, supply reliability, and manufacturability dominate. For Korlym, dose flexibility, adherence, tolerability, and specialty packaging may justify higher development spending.

What licensing and partnership opportunities exist?

The most credible licensing opportunities are formulation and supply-chain based rather than molecule based.

Potential deal structures include:

1. Licensing an orally disintegrating or dispersible mifepristone platform.
2. Supplying a qualified low-moisture excipient system to multiple generic manufacturers.
3. Partnering on a mifepristone-misoprostol co-packaged regimen.
4. Licensing a regional product for countries with limited pharmacy infrastructure.
5. Providing contract development and manufacturing services for a 505(b)(2) product.
6. Acquiring rights to a specialty Korlym formulation or lower-strength presentation.
7. Establishing dual-source excipient agreements with public-sector suppliers.

A valuable excipient partnership must offer more than a proprietary ingredient name. The partner should be able to demonstrate improved dissolution, process yield, stability, tablet robustness, or regulatory efficiency.

What litigation and settlement risks affect mifepristone?

Mifepristone has faced major litigation and regulatory challenges concerning FDA approval, distribution, and dispensing conditions. The U.S. Supreme Court dismissed the principal 2024 challenge on standing grounds without deciding the underlying merits of FDA's approval or regulatory actions.[9]

The litigation environment still creates business risk through:

• potential future challenges to FDA actions;
• state-level restrictions;
• pharmacy and wholesaler participation;
• insurer and payer policies;
• injunction risk;
• inventory allocation;
• product liability and recall exposure.

Patent settlements should be evaluated separately from regulatory litigation. A settlement involving a listed formulation or method patent could establish a delayed generic entry date, authorized-generic arrangement, supply commitment, or license. Publicly available litigation and Orange Book records should control any transaction analysis.

What generic launch scenarios exist for mifepristone?

Immediate generic entry

A manufacturer can launch a conventional 200 mg tablet if it secures FDA approval, satisfies applicable distribution requirements, and avoids or resolves relevant patent and regulatory barriers. This scenario produces rapid price competition and limited differentiation.

Differentiated generic or 505(b)(2) entry

A manufacturer can pursue an orally disintegrating tablet, dispersible tablet, or co-packaged regimen. This strategy may command a commercial premium but requires additional clinical, stability, and regulatory work.

Authorized or licensed supply

A company can enter through a supply or licensing relationship with an existing sponsor. This reduces development risk but limits control over pricing, labeling, distribution, and market access.

Public-sector and international launch

A low-cost, heat-stable product with simplified packaging could target tenders, nonprofit procurement, and international reproductive-health programs. The principal constraints would be local registration, procurement qualification, pharmacovigilance, and political or distribution restrictions.

Key Takeaways

• Conventional mifepristone tablets use standard excipients and offer limited formulation-based exclusivity.
• The principal U.S. commercial products are Mifeprex 200 mg, generic mifepristone 200 mg tablets, and Korlym 300 mg.
• Core molecule exclusivity has expired; regulatory controls and distribution conditions remain material barriers.
• The strongest excipient opportunities are heat-stable tablets, orally disintegrating or dispersible products, co-packaged mifepristone-misoprostol regimens, and improved Korlym dose presentations.
• A routine excipient substitution is unlikely to support durable patent protection.
• A novel dosage form with a measurable clinical or manufacturing benefit could support a 505(b)(2) strategy and stronger formulation claims.
• Generic competition will pressure pricing in medication abortion, while Korlym remains a specialty-market opportunity.
• Commercial diligence should include Orange Book listings, Paragraph IV certifications, FDA REMS requirements, state distribution rules, and current litigation records.

FAQs About Mifepristone Excipients and Commercial Strategy

Can a new excipient create patent protection for mifepristone?

Yes, but only if the claimed composition is novel and non-obvious and produces a meaningful technical result. A routine substitution of one standard binder or disintegrant for another is unlikely to provide durable protection.

Is an orally disintegrating mifepristone tablet commercially viable?

It may be viable where water access, privacy, adherence, or decentralized dispensing creates a patient benefit. The principal development issues are taste, moisture sensitivity, dose uniformity, and tablet robustness.

Would a mifepristone-misoprostol combination be approved as a generic?

A single combined tablet would likely require more than a conventional ANDA strategy because it changes the dosage form and combines active ingredients. A co-packaged kit may have a simpler development path, depending on the proposed claims and regulatory design.

What is the largest excipient supply opportunity in mifepristone?

The largest near-term opportunity is likely a low-cost, high-throughput tablet platform with reliable dissolution and strong heat-and-humidity stability. This aligns with generic production and public-sector procurement needs.

Does Korlym have the same formulation opportunity as Mifeprex?

No. Korlym is a chronic specialty product for Cushing's syndrome, while Mifeprex is primarily associated with a short-course medication-abortion regimen. Korlym may support opportunities in dose flexibility, adherence, and specialty packaging that are less relevant to Mifeprex.

References

1. U.S. Food and Drug Administration. (2023). Mifeprex (mifepristone) tablets, 200 mg: Prescribing information. Danco Laboratories.
2. U.S. Food and Drug Administration. (2024). Korlym (mifepristone) tablets, 300 mg: Prescribing information. Corcept Therapeutics.
3. U.S. Food and Drug Administration. (2020). FDA approves first generic of Mifeprex (mifepristone).
4. Corcept Therapeutics. (2024). Korlym product information and clinical use materials.
5. U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations: Orange Book.
6. U.S. Food and Drug Administration. (2023). FDA modifies risk evaluation and mitigation strategy for Mifeprex.
7. U.S. Food and Drug Administration. (2023). Applications covered by section 505(b)(2).
8. U.S. Food and Drug Administration. (2024). Drugs@FDA: Mifepristone products and approval records.
9. Supreme Court of the United States. (2024). Food and Drug Administration v. Alliance for Hippocratic Medicine, 602 U.S. ___ (2024).