List of Excipients in Branded Drug MEGESTROL ACETATE

Company	Tradename	Ingredient	NDC	Excipient	Potential Generic Entry
Par Pharmaceutical Inc	MEGESTROL ACETATE	megestrol acetate	49884-230	CITRIC ACID MONOHYDRATE
Par Pharmaceutical Inc	MEGESTROL ACETATE	megestrol acetate	49884-230	DOCUSATE SODIUM
Par Pharmaceutical Inc	MEGESTROL ACETATE	megestrol acetate	49884-230	HYPROMELLOSE 2208
Par Pharmaceutical Inc	MEGESTROL ACETATE	megestrol acetate	49884-230	LEMON

Generic Drugs Containing MEGESTROL ACETATE

Company	Ingredient	NDC	Excipient
West-Ward Pharmaceuticals Corp	megestrol acetate	0054-3542	ANHYDROUS CITRIC ACID
West-Ward Pharmaceuticals Corp	megestrol acetate	0054-3542	CARBOXYMETHYLCELLULOSE SODIUM
West-Ward Pharmaceuticals Corp	megestrol acetate	0054-3542	CELLULOSE, MICROCRYSTALLINE
West-Ward Pharmaceuticals Corp	megestrol acetate	0054-3542	POLYOXYL 35 CASTOR OIL

What are the Most Frequently-Used Excipients in MEGESTROL ACETATE?

# Of NDCs	Excipient
5	ACACIA
9	ALCOHOL
8	ANHYDROUS CITRIC ACID
1	ANHYDROUS DIBASIC CALCIUM PHOSPHATE

Last updated: August 12, 2026

Megestrol acetate is a mature, low-cost small-molecule product with limited active-ingredient exclusivity and meaningful formulation opportunities. The strongest commercial positions are concentrated in oral suspensions, especially high-concentration, low-volume products that improve dose accuracy, palatability, redispersibility, storage stability, and use in elderly, oncology, hospice, and dysphagia populations. Tablet products remain difficult to differentiate except through manufacturing efficiency, packaging, and supply reliability.

Megestrol Acetate Excipient Strategy and Commercial Opportunities

What is the commercial status of megestrol acetate?

Megestrol acetate is a synthetic progestin marketed primarily in two oral dosage forms:

Product type	Representative strength	Main clinical use	Commercial position
Tablets	20 mg and 40 mg	Advanced breast or endometrial cancer	Mature generic market
Oral suspension	40 mg/mL	Anorexia, cachexia, or significant unexplained weight loss in patients with AIDS	Generic and branded suspension market
High-concentration suspension	125 mg/mL, equivalent to 625 mg/5 mL	Same indication as oral suspension	Differentiated low-volume product

The most commercially relevant branded reference product is Megace ES, a 625 mg/5 mL oral suspension. FDA approved Megace ES under NDA 021778 in 2005. The product uses a substantially higher concentration than conventional 40 mg/mL megestrol acetate suspension, reducing the administration volume for the labeled 800 mg daily dose from 20 mL to approximately 6.4 mL.[1]

Megestrol acetate is a small molecule. Biosimilar competition is therefore irrelevant. Competitive risk comes from abbreviated new drug applications, authorized generics, formulation development, compounding, and hospital or institutional purchasing contracts.

When does megestrol acetate lose exclusivity?

Megestrol acetate has no meaningful current compound-patent barrier in the United States. The active ingredient and conventional oral dosage forms have been marketed for decades. Commercial barriers are primarily formulation, regulatory, manufacturing, and channel-related rather than molecule-based.

The relevant exclusivity structure is:

Exclusivity category	Relevance to megestrol acetate
New chemical entity exclusivity	Expired
Orphan-drug exclusivity	Not the principal barrier for current oral products
Pediatric exclusivity	No known current commercial significance
Product-specific approval exclusivity	Historical significance for Megace ES, but not a current broad market barrier
Patent exclusivity	Historical formulation and manufacturing claims may have existed; conventional products are generally exposed to generic competition
Biosimilar exclusivity	Not applicable

The FDA Orange Book identifies listed patents and regulatory exclusivity for approved reference products. A current product-specific freedom-to-operate review must distinguish between expired patents, unexpired patents, delisted patents, and patents that do not materially cover a proposed formulation.[2]

What is the Orange Book status of megestrol acetate?

Megestrol acetate products have historically appeared in the Orange Book as prescription tablets and oral suspensions. The principal Orange Book question for a new entrant is not whether megestrol acetate itself is patent protected. It is whether the proposed product must address any unexpired patent listed against the relevant reference product.

For an ANDA, the applicant typically evaluates Paragraph I through Paragraph IV certification options under 21 U.S.C. § 355(j). A Paragraph IV certification is relevant only if an unexpired listed patent covers the reference product and the proposed generic does not infringe or the patent is invalid.[3]

What excipients are used in megestrol acetate products?

Megestrol acetate formulations use excipients for wetting, particle suspension, taste control, preservation, viscosity control, and tablet manufacturability.

Oral suspension excipients

Representative branded high-concentration suspension excipients include:

• Sucrose
• Citric acid monohydrate
• Polysorbate 80
• Sodium benzoate
• Natural and artificial flavoring
• Purified water

The Megace ES labeling identifies a 625 mg/5 mL suspension containing sucrose, citric acid monohydrate, polysorbate 80, sodium benzoate, flavoring, and water.[1]

Conventional 40 mg/mL suspensions may use a different system, including:

• Sucrose or another sweetener
• Xanthan gum or a comparable suspending polymer
• Polysorbate 80 or another wetting agent
• Sodium benzoate or another preservative
• Citric acid or citrate buffer
• Flavoring
• Water
• Alcohol in some legacy formulations

Excipients vary by manufacturer. The formulation cannot be copied solely from the reference label because critical properties such as particle-size distribution, polymer grade, preservative concentration, flavor composition, and mixing order affect performance.

Tablet excipients

Representative megestrol acetate tablets use conventional solid-dose excipients such as:

• Lactose monohydrate
• Microcrystalline cellulose
• Colloidal silicon dioxide
• Sodium starch glycolate
• Magnesium stearate

Tablet differentiation is limited because the active dose is small relative to the total tablet mass, and the formulation is compatible with standard wet granulation, dry granulation, or direct-compression processes depending on powder properties.

What formulation characteristics matter most for megestrol acetate suspension?

The principal technical challenge is creating a stable, palatable, high-strength suspension from a poorly water-soluble active pharmaceutical ingredient.

1. Suspension stability

The formulation must control:

• Sedimentation rate
• Cake formation
• Redispersibility after storage
• Particle-size growth
• Dose uniformity throughout bottle use
• Viscosity at both storage and dispensing temperatures

A high-concentration suspension has less formulation margin than a 40 mg/mL product. Poor wetting or excessive particle interaction can produce hard sediment and inaccurate dosing.

A polymer system based on xanthan gum, hydroxypropyl cellulose, microcrystalline cellulose with carboxymethylcellulose, or another suspending agent can improve physical stability. The selection must balance suspension performance against pourability and syringe delivery.

2. Wetting and dispersion

Megestrol acetate particles need rapid wetting during manufacture and after settling. Polysorbate 80 is used in the reference high-concentration product, but alternative surfactants may provide opportunities for preservative compatibility, reduced foaming, or improved sensory properties.

Potential development variables include:

• Surfactant type and concentration
• Particle-size distribution
• Milling method
• Powder deagglomeration
• Order of excipient addition
• Homogenization energy
• Bulk density and sediment volume

A smaller particle size may improve dose uniformity but can increase agglomeration, viscosity, or processing cost.

3. Palatability

Megestrol acetate suspension is administered to patients who may have cancer, AIDS-related wasting, anorexia, dysphagia, or significant weakness. Taste and mouthfeel are therefore commercial variables, not cosmetic attributes.

Useful strategies include:

• Lemon-lime or fruit flavor systems
• Sucrose reduction or replacement
• Bitter-blocking agents
• Controlled-release flavor systems
• Reduced surfactant levels
• Lower viscosity for easier swallowing
• Lower aftertaste and reduced oral coating

The reference product uses a sweetened, flavored formulation. A sugar-free product could target patients with diabetes, hyperglycemia risk, dental concerns, or institutional restrictions. The replacement sweetener must not compromise viscosity, osmolarity, preservative performance, or taste.

4. Dose-volume reduction

Megace ES delivers 800 mg in approximately 6.4 mL. This is a central product advantage over conventional 40 mg/mL suspension, which requires 20 mL for the same daily dose.

A new product could compete through:

• Equivalent high concentration
• A prefilled oral syringe
• A smaller bottle with lower fill volume
• A unit-dose cup or sachet
• A concentrated formulation that does not require dilution
• A more accurate dosing device

The dose device is part of the commercial proposition. A bottle without a reliable oral syringe creates avoidable dosing risk, particularly in home-care and long-term-care settings.

What formulation patents could protect a new megestrol acetate product?

A conventional composition containing megestrol acetate, sucrose, polysorbate 80, sodium benzoate, flavor, and water is unlikely to create a strong standalone patent position unless the formulation has a narrow, non-obvious technical advantage.

Potential patentable subject matter includes:

Patent strategy	Potential claim focus
High-concentration suspension	Specific concentration, particle-size distribution, viscosity range, and redispersibility
Sugar-free product	Sweetener system, preservative system, taste masking, and stability
Improved palatability	Flavor and bitter-blocking combination with measurable sensory performance
Enhanced dose uniformity	Particle engineering and manufacturing process
Long-term stability	Defined pH, preservative level, container closure, and degradation profile
Device combination	Bottle, adapter, syringe, and dose-metering system
Unit-dose product	Sachet or cup packaging with stability and dosing claims
Ready-to-administer product	Institutional packaging and handling properties
Compounding alternative	Pharmacy-prepared formulation with improved beyond-use or preservation characteristics

Method-of-use patents are less attractive because the principal approved uses are old and well known. A new method-of-use position would require a specific patient population, dosing regimen, combination treatment, or clinical outcome supported by robust data.

How strong is the patent estate for megestrol acetate?

The active-ingredient estate is weak because megestrol acetate is old and widely genericized. A new entrant should not rely on composition-of-matter exclusivity.

The strongest potential intellectual-property positions are likely to be:

1. A technically differentiated high-concentration suspension.
2. A sugar-free or excipient-reduced formulation.
3. A device-integrated presentation.
4. A manufacturing process that improves uniformity or reduces batch failure.
5. A packaging system that extends stability or simplifies institutional use.

Patent strength will depend on comparative data. Useful evidence includes accelerated and long-term stability, redispersibility after controlled settling, delivered-dose uniformity, preservative effectiveness, particle-size stability, and sensory testing.

Trade-secret protection may be more valuable than patents for mixing order, milling parameters, polymer hydration, flavor incorporation, and scale-up controls. These process variables can be difficult to infer from the final product.

What generic entry risks exist for Megace ES?

Megace ES faces several forms of competition:

ANDA competition

A generic high-concentration suspension may pursue therapeutic equivalence to the reference product. The applicant must address formulation sameness or permitted differences, inactive-ingredient safety, product performance, and device compatibility.

For oral suspensions, the most important development risks include:

• Failure to demonstrate equivalent active content
• Inadequate delivered-dose uniformity
• Different particle-size distribution
• Poor redispersibility
• Preservative failure
• Inconsistent viscosity
• Flavor differences that affect patient acceptance
• Container-closure interaction
• Syringe dosing inaccuracy

Authorized-generic competition

The reference-product sponsor or a commercial partner can market an authorized generic at a lower price. This can compress margins quickly after generic entry and reduce the value of a formulation-only launch.

Pharmacy compounding

Compounding pharmacies may supply megestrol acetate suspensions, especially when commercial products are unavailable or when facilities require sugar-free or customized strengths. Compounded products can compete on flexibility but generally have less standardized stability, packaging, and supply consistency.

Institutional purchasing

Hospice, oncology, skilled nursing, and hospital systems often evaluate products on total acquisition cost, dosing convenience, shortage history, and formulary compatibility. A differentiated product needs a clear operational benefit rather than only a new flavor.

Which companies are challenging the megestrol acetate market?

The market is populated by generic manufacturers and distributors rather than a concentrated group of originator companies. Product availability has varied by dosage form and manufacturer. The relevant competitive set includes:

• Tablet manufacturers producing 20 mg and 40 mg strengths
• Conventional 40 mg/mL suspension suppliers
• High-concentration suspension suppliers
• Authorized-generic distributors
• Compounding pharmacies
• Contract manufacturers with oral-liquid capabilities

The most important competitive comparison is not company reputation. It is whether a supplier can maintain validated suspension performance, dependable supply, and acceptable pricing.

What commercial opportunities exist for new megestrol acetate excipients?

Sugar-free high-concentration suspension

This is the clearest formulation opportunity. A sugar-free product could target patients with diabetes, glucose intolerance, or institutional policies restricting sucrose-containing medicines. The product would need robust taste masking and preservative validation.

Alcohol-free formulation

An alcohol-free product could appeal to pediatric-adjacent caregivers, hospice providers, faith-sensitive populations, and institutions seeking simpler excipient profiles. Alcohol-free positioning is most useful when combined with improved taste and dosing convenience.

Dysphagia-focused presentation

Megestrol acetate is used in patients who may have swallowing difficulties. A product with lower viscosity, a calibrated syringe, and a smaller administration volume could compete in long-term-care and hospice channels.

Unit-dose and pouch packaging

Single-dose packaging could reduce medication errors, simplify nurse administration, and support hospice or institutional workflows. The tradeoff is higher packaging cost and potentially greater waste.

Low-cost, reliable conventional suspension

A 40 mg/mL product remains commercially relevant where reimbursement favors acquisition cost over concentration. Manufacturing efficiency, stable supply, and a familiar excipient profile may provide better returns than a heavily engineered product.

Excipient supply and contract development

Excipient companies can support this market through:

• Suspending-agent systems
• Taste-masking platforms
• Sugar-free sweetener systems
• Preservative alternatives
• Oral syringe and dosing adapters
• Ready-to-use premixes
• Scale-up and process-development services

How does megestrol acetate compare with competing appetite-stimulant products?

Megestrol acetate competes clinically with mirtazapine, dronabinol, corticosteroids, nutritional support, and nonpharmacologic care. These products have different indications, evidence bases, adverse-effect profiles, and reimbursement dynamics.

Product	Formulation opportunity relative to megestrol acetate
Megestrol acetate	Strongest opportunity in high-concentration suspension and taste improvement
Dronabinol	Oral solution and capsule convenience, but controlled-substance considerations
Mirtazapine	Tablet and orally disintegrating formats; different therapeutic positioning
Corticosteroids	Low-cost tablets and liquids, but different risk-benefit profile
Nutritional products	Flavor, texture, protein density, and disease-specific nutrition

Megestrol acetate has clinically important risks, including thromboembolic events, adrenal suppression, and glucocorticoid-like effects. FDA labeling limits its role and does not establish broad use for routine weight gain in all populations.[1] A commercial strategy should therefore target labeled or clearly supportable use rather than expand into unsupported wellness or general weight-loss markets.

What regulatory pathway applies to a new formulation?

A conventional generic tablet or suspension would generally use the ANDA pathway. A materially different formulation, new dosage form, or product with a distinct clinical claim may require a 505(b)(2) application.

The regulatory path depends on:

• Whether the product is pharmaceutically equivalent to the reference
• Whether the excipients are listed in FDA’s Inactive Ingredient Database for the route and dosage form
• Whether the formulation introduces a novel excipient or higher-than-established level
• Whether clinical pharmacology or clinical efficacy data are needed
• Whether the delivery device affects dose administration
• Whether the proposed labeling differs from the reference product

FDA’s Inactive Ingredient Database can support excipient selection and reduce regulatory risk when the selected excipient, route, and dosage form have established use.[4] Novel excipient strategies increase development value but also increase CMC and regulatory burden.

What litigation and settlement risks affect a launch?

Megestrol acetate does not present the litigation profile of an active blockbuster with a large, current Orange Book patent estate. Litigation risk is more likely to arise from:

• Paragraph IV challenges to any surviving listed patent
• Patent disputes involving high-concentration suspension claims
• Trade-secret claims involving manufacturing processes
• Trademark or trade-dress disputes
• Contract disputes with API or suspension manufacturers
• Device patents covering oral syringes or bottle adapters

Any settlement agreement involving a listed patent would need review for launch timing, authorized-generic provisions, supply terms, and potential antitrust exposure. The absence of a prominent current patent dispute does not eliminate the need for product-specific freedom-to-operate diligence.

What launch scenarios are commercially realistic?

Base-case generic launch

A manufacturer launches a standard tablet or 40 mg/mL suspension. The product competes primarily on price and supply reliability. Gross margins are likely to be constrained.

Premium differentiated suspension

A manufacturer launches a 625 mg/5 mL or comparable high-concentration suspension with improved taste, a calibrated syringe, and strong stability data. This supports a higher price if payers and institutional buyers recognize lower administration burden.

Institutional specialty launch

A supplier targets hospice, skilled nursing, oncology clinics, and long-term-care pharmacies with unit-dose packaging, alcohol-free composition, and reliable delivery. The addressable market is narrower but may support lower customer-acquisition costs.

Platform licensing

A formulation developer licenses a suspension platform to a generic manufacturer or specialty-pharmaceutical company. The value lies in a transferable process, excipient system, device package, or regulatory-ready development dossier.

Key Takeaways

• Megestrol acetate has limited active-ingredient exclusivity and no biosimilar risk.
• The main commercial opportunity is oral-suspension differentiation, not conventional tablets.
• High concentration reduces administration volume and is the strongest established product attribute.
• Sugar-free, alcohol-free, low-volume, taste-masked, and device-integrated products are the most credible formulation opportunities.
• Patent protection is more realistic for a narrowly defined composition, process, or device than for megestrol acetate itself.
• ANDA competition, authorized generics, and pharmacy compounding are the principal market-entry risks.
• A commercially viable product needs evidence of dose uniformity, redispersibility, palatability, preservative effectiveness, and stability.
• Institutional channels may value packaging and administration efficiency more than minor excipient changes.
• A conventional low-cost generic can succeed through supply reliability, while a premium product needs measurable clinical or operational advantages.

FAQs

Is megestrol acetate suspension still commercially attractive?

Yes, but primarily as a differentiated oral-liquid product. The opportunity is strongest where lower administration volume, taste, dosing accuracy, or specialized packaging reduces caregiver and patient burden.

Can a sugar-free megestrol acetate suspension be patented?

Potentially. Patentability would depend on a non-obvious excipient combination and demonstrated technical benefits such as improved taste, stability, redispersibility, or preservative performance.

Does megestrol acetate require a novel excipient for product differentiation?

No. Differentiation can use excipients with established FDA route and dosage-form precedent. Novel excipients may strengthen intellectual property but increase regulatory and development requirements.

Is Megace ES protected by a current composition-of-matter patent?

No. Megestrol acetate is an old active ingredient. Any relevant current protection would need to arise from product-specific formulation, process, device, or other narrow claims rather than the molecule itself.

Which excipient technology offers the best return potential?

A high-concentration, sugar-free, palatable suspension with validated syringe dosing offers the strongest combination of patient utility, institutional relevance, and potential formulation differentiation.

References

1. U.S. Food and Drug Administration. (2005). Megace ES (megestrol acetate) oral suspension prescribing information.
2. U.S. Food and Drug Administration. (n.d.). Approved drug products with therapeutic equivalence evaluations: Orange Book.
3. U.S. Food and Drug Administration. (2024). Abbreviated new drug application submissions: Content and format of an ANDA.
4. U.S. Food and Drug Administration. (n.d.). Inactive Ingredient Database.
5. DailyMed. (n.d.). Megestrol acetate tablet and oral suspension labeling. National Library of Medicine.