List of Excipients in Branded Drug BUTALBITAL AND ACETAMINOPHEN

Generic Drugs Containing BUTALBITAL AND ACETAMINOPHEN

Company	Ingredient	NDC	Excipient
Endo USA	butalbital and acetaminophen	0603-2540	CELLULOSE, MICROCRYSTALLINE
Endo USA	butalbital and acetaminophen	0603-2540	CROSCARMELLOSE SODIUM
Endo USA	butalbital and acetaminophen	0603-2540	CROSPOVIDONE
Endo USA	butalbital and acetaminophen	0603-2540	POVIDONE
Endo USA	butalbital and acetaminophen	0603-2540	SILICON DIOXIDE
Endo USA	butalbital and acetaminophen	0603-2540	STARCH, CORN
Endo USA	butalbital and acetaminophen	0603-2540	STEARIC ACID

What are the Most Frequently-Used Excipients in BUTALBITAL AND ACETAMINOPHEN?

# Of NDCs	Excipient
1	AMMONIA
17	CELLULOSE, MICROCRYSTALLINE
16	CROSCARMELLOSE SODIUM
16	CROSPOVIDONE
2	D&C YELLOW NO. 10
4	FD&C BLUE NO. 1
3	FD&C RED NO. 3

Last updated: August 9, 2026

ecutive summary: Butalbital and acetaminophen is a mature, genericized prescription combination with limited patent value and moderate formulation opportunity. The strongest commercial positions are differentiated immediate-release tablets or capsules that improve dose uniformity, swallowability, stability, packaging, or pharmacy substitution economics. New excipients are unlikely to create meaningful exclusivity by themselves. The principal development risks are acetaminophen hepatotoxicity, butalbital overuse and dependence, controlled-substance handling in some jurisdictions, formulation variability, and limited clinical differentiation.

Butalbital and Acetaminophen Excipient Strategy and Commercial Opportunities

What is the commercial profile of butalbital and acetaminophen?

Butalbital and acetaminophen is an oral combination used for tension or muscle-contraction headaches. Marketed products commonly contain 50 mg of butalbital and 300 mg of acetaminophen per unit. Some products add 40 mg of caffeine, while others omit caffeine. Fioricet is the best-known branded formulation containing butalbital, acetaminophen, and caffeine.

The combination is generally sold as an immediate-release tablet or capsule. It is prescription-only because of butalbital’s central nervous system effects and abuse potential. Products containing codeine have a separate opioid risk profile and should not be treated as equivalent to non-codeine butalbital-acetaminophen products.

Attribute	Commercial position
Active ingredients	Butalbital and acetaminophen, with or without caffeine
Typical strength	Butalbital 50 mg plus acetaminophen 300 mg
Dosage forms	Immediate-release tablets and capsules
Prescription status	Prescription drug
Primary therapeutic use	Tension headache
Generic availability	Broad
Biosimilar exposure	None
Principal safety issue	Acetaminophen overdose and liver injury
Principal controlled-substance issue	Butalbital misuse, dependence, and withdrawal
Main formulation opportunity	Better manufacturability, swallowability, stability, and packaging

FDA-approved labeling limits the product to short-term use in many formulations and warns against exceeding the prescribed dose or combining it with other acetaminophen-containing products.[1] The commercial opportunity is therefore concentrated in reliable prescription supply and product differentiation rather than mass-market expansion.

What excipients are used in butalbital and acetaminophen products?

Published product labels show that manufacturers use conventional solid-dose excipients. The exact composition depends on the product, dosage form, supplier, and manufacturing process.

Common tablet excipients

Typical inactive ingredients may include:

• Microcrystalline cellulose
• Pregelatinized starch or maize starch
• Croscarmellose sodium
• Povidone
• Colloidal silicon dioxide
• Magnesium stearate
• Talc
• Crospovidone
• Lactose or other filler systems
• Film-coating polymers, pigments, and plasticizers

DailyMed labels for butalbital-acetaminophen products identify variations in fillers, binders, disintegrants, lubricants, and colorants across manufacturers.[2] These variations create room for process and product optimization, but they do not automatically produce patentable subject matter.

Common capsule excipients

Hard-gelatin capsules generally use a powder blend containing a diluent, disintegrant, glidant, and lubricant. The shell may contain gelatin, titanium dioxide, colorants, and printing ink. A capsule can improve patient acceptability where the tablet is large, strongly colored, or associated with a bitter taste.

The key technical challenge is blend uniformity. Butalbital is present at a lower mass than acetaminophen and can segregate during blending, transfer, or capsule filling. A formulation with poor particle-size matching or excessive flow-aid content can produce content-uniformity failures even when the final assay is acceptable.

Which excipient strategy is strongest for product development?

The most defensible strategy is a conventional, risk-controlled platform rather than an exotic excipient system. The formulation should be designed around four objectives: content uniformity, rapid and reproducible dissolution, acceptable tablet handling, and low moisture sensitivity.

Recommended functional excipient architecture

Function	Preferred options	Development rationale
Diluent	Microcrystalline cellulose, lactose, dibasic calcium phosphate	Controls tablet weight and compression behavior
Binder	Povidone, pregelatinized starch, dry-binder cellulose	Improves granule or tablet strength
Disintegrant	Croscarmellose sodium, crospovidone, sodium starch glycolate	Supports immediate release
Glidant	Colloidal silicon dioxide	Improves powder flow and filling accuracy
Lubricant	Magnesium stearate, sodium stearyl fumarate	Reduces sticking and ejection force
Moisture control	Low-moisture excipient grades, protective packaging	Reduces hydrolytic and physical instability
Taste and appearance	Film coating, capsule shell, pigment system	Improves acceptability and product identification

A direct-compression formula can reduce manufacturing complexity and cost. It requires strong control of particle-size distribution, flow, segregation, and compressibility. Roller compaction or wet granulation can improve uniformity where the active ingredients have incompatible flow or density properties, but those processes add equipment, validation, and scale-up costs.

Content uniformity is the primary technical hurdle

The product combines a relatively low-dose barbiturate with a high-dose analgesic. A robust formula should control:

1. Active-ingredient particle-size distribution.
2. Order of ingredient addition.
3. Blend time and shear exposure.
4. Hopper residence time.
5. Segregation during transfer.
6. Lubrication time.
7. Compression force and tablet weight.

A premix or ordered dilution approach can improve distribution of butalbital before final blending. The strategy should be supported by blend-uniformity sampling, stratified compression studies, and dosage-unit uniformity testing under the relevant USP and FDA expectations.[3]

What formulation patents could protect butalbital and acetaminophen products?

Formulation patents are more plausible than composition-of-matter patents because both active ingredients are longstanding compounds. Potentially protectable subject matter includes:

• A defined excipient ratio that produces a specific dissolution profile.
• A low-segregation powder blend with specified particle-size distributions.
• A moisture-protective formulation with improved stability.
• A taste-masked tablet or capsule.
• A modified-release product, if clinically justified.
• An orally disintegrating tablet with acceptable butalbital exposure.
• A combination product that reduces tablet size or improves swallowing.
• A manufacturing process that consistently achieves content uniformity.
• A packaging and formulation combination that limits moisture or light degradation.

A patent application must claim a technical result supported by comparative data. Generic use of microcrystalline cellulose, magnesium stearate, or croscarmellose sodium is unlikely to provide strong protection. The strongest claims would link a narrow composition or process to measurable performance, such as dissolution, impurity control, content uniformity, friability, or stability.

Are method-of-use patents commercially important?

Method-of-use patents have limited value for the established tension-headache indication. A new indication, dosing regimen, patient subgroup, or safety-based administration protocol could create a distinct claim set, but clinical and regulatory evidence would be required.

A method-of-use strategy would face several obstacles:

• The active ingredients have long clinical histories.
• Physicians may prescribe generic equivalents.
• Labeling must support the claimed use.
• Induced-infringement theories can be difficult where the product has broad non-infringing uses.
• Butalbital’s dependence and medication-overuse risks limit aggressive expansion into chronic headache treatment.

A practical formulation patent is generally more commercially credible than a broad new-use patent for this product class.

What is the FDA and Orange Book status of butalbital and acetaminophen?

The product class is regulated as an approved prescription drug, usually through abbreviated new drug applications for generic products or legacy approved applications for branded combinations. The FDA Orange Book identifies approved drug products and patent or exclusivity information for listed applications.[4]

For a standard butalbital-acetaminophen generic, the principal regulatory pathway is an ANDA demonstrating pharmaceutical equivalence and bioequivalence to the applicable reference product. Excipients may differ from the reference product if the final product meets FDA requirements for safety, quality, performance, and labeling.

Regulatory issue	Commercial implication
ANDA pathway	Lower development cost than a new clinical product
Immediate-release dosage form	Usually supports conventional bioequivalence methods
Caffeine inclusion	Creates a different active-ingredient combination and reference-product issue
Acetaminophen content	Requires strict strength and labeling control
Butalbital content	Requires controls for uniformity and abuse-related risks
New excipient	May require additional safety justification
Color or shell changes	May affect appearance but usually do not create exclusivity
Product-specific labeling	Must address overdose, dependence, and sedative effects

A new excipient would increase regulatory complexity. FDA’s inactive-ingredient database can support precedent for route, dosage form, and concentration, but it does not guarantee approval for a new formulation.[5] Using established excipients at precedent-supported levels is usually the lowest-risk strategy.

When does butalbital and acetaminophen lose exclusivity?

The active ingredients and conventional combination products are mature. Commercial exclusivity is generally no longer the main barrier to entry. Any remaining protection is more likely to arise from a specific formulation, dosage form, regulatory exclusivity period, trademark, or manufacturing capability than from basic active-ingredient rights.

No biosimilar pathway applies because butalbital and acetaminophen are small-molecule drugs. The relevant competition is from generic tablets, capsules, and combination products, not biosimilars.

Are Paragraph IV challenges relevant?

Paragraph IV certifications can arise if an ANDA applicant challenges a listed patent associated with a reference product. For a mature product with limited or expired patent protection, Paragraph IV litigation may be less important than ordinary ANDA filing, product quality, and commercial launch execution.

The strategic value of a Paragraph IV filing depends on:

• Whether any Orange Book patent remains listed.
• Whether the patent claims the active product, formulation, or method of use.
• Whether the applicant can obtain a 180-day generic exclusivity period.
• Whether the reference product has meaningful remaining sales.
• Whether a settlement would delay launch or preserve market allocation.

A formulation patent covering a differentiated excipient system would have greater litigation relevance than a weak patent claiming a routine tablet excipient.

What generic entry risks exist for a new butalbital-acetaminophen product?

Generic entry risk is high because multiple manufacturers can produce conventional immediate-release products using widely available excipients. A new product must therefore compete on cost, supply reliability, or a clearly differentiated dosage form.

Principal entry risks

Price compression: Multiple ANDA holders can reduce reimbursement and wholesaler pricing.

Substitution: Pharmacies and payers may favor lower-cost generic products unless the formulation has a recognized clinical or operational advantage.

Low switching friction: Prescribers can usually substitute among conventional strengths and dosage forms subject to state and payer rules.

Supply-chain exposure: Acetaminophen, capsule shells, excipients, and packaging components are available from multiple sources, but quality events or manufacturing interruptions can cause shortages.

Regulatory scrutiny: FDA review will focus on pharmaceutical equivalence, bioequivalence, manufacturing controls, impurities, and labeling.

Safety-driven demand constraints: Chronic use is commercially limited by medication-overuse headache, sedation, dependence, and acetaminophen toxicity concerns.[1,6]

What commercial opportunities exist in excipient-led product design?

Smaller and easier-to-swallow tablets

A reduced tablet weight or a capsule with improved powder density can address swallowing concerns. The opportunity is strongest where current products are bulky or have poor mechanical properties. The product must retain dose uniformity and immediate release.

Improved stability and packaging

A low-moisture formula paired with high-barrier blister packaging can reduce degradation and improve shelf life. Unit-dose packaging also supports controlled dispensing and may reduce medication errors involving acetaminophen-containing products.

Taste masking and orally disintegrating delivery

An orally disintegrating tablet could improve administration for patients with swallowing difficulty. Butalbital’s bitterness and the high acetaminophen load make taste masking technically demanding. Ion-exchange resins, polymer coatings, or multiparticulate systems could be evaluated, but these approaches raise cost and may delay dissolution.

Caffeine-free positioning

A caffeine-free formulation may appeal to patients who experience insomnia, palpitations, anxiety, or caffeine-related headache effects. It would need to be positioned as a separate active-ingredient combination, with appropriate reference-product and bioequivalence analysis.

Authorized generic or contract manufacturing

A manufacturer with reliable capacity could pursue an authorized-generic arrangement, contract manufacturing, or supply agreement with a branded or specialty pharmaceutical company. The value proposition would be dependable supply, validated manufacturing, and competitive cost rather than patent exclusivity.

How does the patent estate compare with the commercial opportunity?

Asset type	Patent strength	Commercial value
Basic butalbital-acetaminophen combination	Low	Established demand, high generic competition
Conventional tablet excipient formula	Low to moderate	Limited unless tied to measurable performance
Low-segregation manufacturing process	Moderate	Useful for quality differentiation and process control
Taste-masked or orally disintegrating product	Moderate	Potential niche pricing if clinically accepted
Moisture-stable formulation and package	Moderate	Supports lifecycle management and supply reliability
New indication	Uncertain	High development burden and safety limitations
Caffeine-free combination	Low patent value	Possible patient-segmentation opportunity
Branded generic with superior supply	Minimal patent value	Potential payer, wholesaler, or institutional value

The best business case is a low-cost, high-reliability generic supported by a focused formulation patent or trade-secret manufacturing process. A high-price specialty product would need meaningful evidence of improved adherence, tolerability, stability, or administration.

What licensing and partnership opportunities are available?

Licensing opportunities are more likely to involve manufacturing and distribution than foundational intellectual property. Relevant structures include:

• Regional commercialization licenses for an ANDA-approved product.
• Authorized-generic supply arrangements.
• Contract development and manufacturing agreements.
• Co-development of an orally disintegrating or taste-masked product.
• Private-label supply for institutional or specialty pharmacies.
• Packaging licenses involving unit-dose or high-barrier systems.

A partner should be evaluated on FDA inspection history, controlled-substance procedures where applicable, acetaminophen quality systems, serialization capability, and ability to maintain uninterrupted supply.

What patent litigation and settlement issues affect the market?

The mature nature of the product class reduces the likelihood that litigation will define the market. Disputes are more likely to concern ANDA patents, product labeling, manufacturing processes, supply contracts, trademark rights, or quality failures.

A settlement involving a formulation patent could establish a delayed launch date, authorized-generic rights, or supply terms. Any agreement should be reviewed for antitrust risk, launch restrictions, allocation provisions, and termination triggers. A patent settlement has limited economic value if several non-party generic manufacturers can enter independently.

Key takeaways

• Butalbital and acetaminophen is a mature, genericized prescription combination.
• Conventional excipients are adequate, but blend uniformity and segregation control are critical.
• The strongest formulation opportunities involve smaller tablets, better stability, taste masking, unit-dose packaging, and improved manufacturing consistency.
• New excipients alone are unlikely to create durable patent protection.
• Formulation and process patents require comparative performance data.
• Biosimilar risk does not apply.
• Paragraph IV risk depends on whether any enforceable Orange Book-listed patent remains relevant to the reference product.
• Commercial returns will depend more on manufacturing cost, supply reliability, payer acceptance, and product differentiation than on basic composition claims.
• Acetaminophen toxicity and butalbital dependence constrain chronic-use expansion.
• The most credible lifecycle strategy is a differentiated immediate-release or orally disintegrating product supported by robust CMC data.

FAQs

Can a new excipient create exclusivity for butalbital and acetaminophen?

Usually not by itself. Exclusivity is more credible when the excipient system produces a novel, reproducible technical effect, such as improved stability, dissolution, dose uniformity, or taste masking.

Is an orally disintegrating butalbital-acetaminophen tablet commercially viable?

It may be viable as a niche product, but bitterness, high acetaminophen loading, rapid dissolution, tablet strength, and packaging stability create substantial development requirements.

Does adding caffeine create a patentable product?

Adding caffeine can define a different active-ingredient combination, but the combination itself may have limited patent value because similar products have been marketed for many years. Regulatory reference-product selection remains important.

Are butalbital-acetaminophen products subject to biosimilar competition?

No. These are small-molecule drug products. Competition comes from ANDA-based generic tablets and capsules and from reformulated combination products.

What is the highest-value manufacturing improvement?

The highest-value improvement is usually a process that consistently prevents butalbital segregation and delivers acceptable content uniformity at commercial scale without materially increasing tablet weight, cycle time, or cost.

References

1. U.S. Food and Drug Administration. (n.d.). Butalbital, acetaminophen, and caffeine prescribing information. DailyMed.
2. National Library of Medicine. (n.d.). DailyMed: Butalbital and acetaminophen product labeling and inactive ingredients. DailyMed.
3. U.S. Pharmacopeia. (2024). United States Pharmacopeia and National Formulary: General chapters on dosage-unit uniformity and dissolution. U.S. Pharmacopeial Convention.
4. U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations: Orange Book.
5. U.S. Food and Drug Administration. (2024). Inactive ingredient database.
6. U.S. Food and Drug Administration. (2018). FDA drug safety communication: Prescription combination drugs containing acetaminophen and risk of liver injury.