CARISOPRODOL AND ASPIRIN Drug Patent Profile

When do Carisoprodol And Aspirin patents expire, and what generic alternatives are available?

Carisoprodol And Aspirin is a drug marketed by Chartwell Rx, Genus, Ingenus Pharms Llc, and Oxford Pharms. and is included in four NDAs.

The generic ingredient in CARISOPRODOL AND ASPIRIN is aspirin; carisoprodol. There is one drug master file entry for this compound. Additional details are available on the aspirin; carisoprodol profile page.

Summary for CARISOPRODOL AND ASPIRIN

US Patents:	0
Applicants:	4
NDAs:	4
DailyMed Link:	CARISOPRODOL AND ASPIRIN at DailyMed

US Patents and Regulatory Information for CARISOPRODOL AND ASPIRIN

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Exclusivity Expiration
Chartwell Rx	CARISOPRODOL AND ASPIRIN	aspirin; carisoprodol	TABLET;ORAL	089594-001	Mar 31, 1989		DISCN	No	No
Oxford Pharms	CARISOPRODOL AND ASPIRIN	aspirin; carisoprodol	TABLET;ORAL	040252-001	Dec 10, 1997		DISCN	No	No
Genus	CARISOPRODOL AND ASPIRIN	aspirin; carisoprodol	TABLET;ORAL	040116-001	Apr 25, 1996		DISCN	No	No
Ingenus Pharms Llc	CARISOPRODOL AND ASPIRIN	aspirin; carisoprodol	TABLET;ORAL	040832-001	Jan 7, 2010		DISCN	No	No

Carisoprodol and Aspirin Market Dynamics, Patent Status, and Financial Trajectory

Last updated: August 19, 2026

Carisoprodol and aspirin is a legacy prescription combination marketed historically as Soma Compound, generally containing carisoprodol 200 mg and aspirin 325 mg. Its commercial position has weakened substantially because of generic substitution, declining use of carisoprodol, controlled-substance restrictions, and competition from single-agent muscle relaxants and nonprescription analgesics. The product has no meaningful current patent moat, no biosimilar exposure, and limited publicly disclosed revenue data.

What is carisoprodol and aspirin used for?

Carisoprodol and aspirin is indicated as an adjunct to rest and physical therapy for acute, painful musculoskeletal conditions. Carisoprodol provides skeletal-muscle-relaxant activity, while aspirin supplies analgesic and anti-inflammatory effects.

The FDA-approved labeling limits treatment to short-term use, generally up to two or three weeks, because evidence for longer-term efficacy is limited and carisoprodol carries risks of sedation, dependence, abuse, and withdrawal. The product is not positioned as a chronic pain therapy. [1]

Attribute	Carisoprodol and aspirin
Historical brand	Soma Compound
Active ingredients	Carisoprodol 200 mg; aspirin 325 mg
Therapeutic category	Skeletal muscle relaxant and analgesic combination
FDA pathway	Legacy prescription NDA
Principal use	Acute painful musculoskeletal conditions
Recommended duration	Up to two or three weeks
Controlled-substance status	Carisoprodol is Schedule IV federally
Biologic status	Small-molecule product; no biosimilar pathway
Current patent profile	No material active Orange Book patent estate identified
Commercial position	Mature, low-growth or declining legacy product

When did carisoprodol and aspirin lose exclusivity?

Carisoprodol and aspirin lost meaningful market exclusivity decades ago. The product originated from legacy FDA approvals associated with the Soma franchise, with FDA records tracing the product to the late 1950s. Any composition-of-matter, formulation, or basic product patents associated with the original product would have expired long before the current market period.

The commercial barriers are therefore regulatory and manufacturing-related rather than patent-based. A manufacturer seeking to market the product would face FDA requirements for an approved application, quality control, controlled-substance compliance, pharmacovigilance, and commercial distribution. It would not face a modern branded-product patent cliff comparable to newer specialty drugs.

Patent and exclusivity timeline

Event	Approximate timing	Commercial effect
Original Soma franchise approval	Late 1950s	Established the branded product
Legacy product and formulation patent period	Expired decades ago	Removed patent-based exclusivity
Generic carisoprodol market expansion	1990s and 2000s	Increased substitution pressure
Federal Schedule IV classification of carisoprodol	January 11, 2012	Increased prescribing and distribution controls
Current period	2020s	Mature product with limited branded value

The FDA Orange Book is the principal source for listed patents and regulatory exclusivity. Current Orange Book records do not indicate a commercially meaningful, unexpired patent estate protecting the legacy carisoprodol-and-aspirin combination. [2]

What patents protect carisoprodol and aspirin?

No active composition, formulation, method-of-use, or manufacturing patent has been identified as a material barrier to generic entry for the legacy combination.

Composition patents

The active ingredients are old, well-characterized small molecules. Carisoprodol was developed and commercialized many decades ago, while aspirin has been available for more than a century. Composition-of-matter protection is therefore expired.

Formulation patents

The product is a conventional oral tablet. There is no known current extended-release, abuse-deterrent, modified-release, or other differentiated formulation patent that materially protects carisoprodol and aspirin as a commercial product.

A manufacturer could pursue a new formulation patent for a genuinely novel dosage form, excipient system, release profile, or abuse-deterrent design. That would protect the new formulation, not the legacy immediate-release combination.

Method-of-use patents

The historical indication is broad and conventional: short-term relief of acute painful musculoskeletal conditions. No active method-of-use patent appears to provide meaningful exclusivity for that indication.

A later patent could theoretically target a defined patient subgroup, dosing regimen, or clinical use. Such a patent would face written-description, enablement, obviousness, and clinical-relevance challenges. It would not restore exclusivity to the legacy product across the full market.

What is the Orange Book status of carisoprodol and aspirin?

The Orange Book does not provide a significant current patent barrier for carisoprodol and aspirin. The product is associated with a legacy NDA rather than an innovative, currently protected branded product.

The important commercial distinction is between FDA approval and market availability:

• An NDA may remain listed even if the product is no longer actively marketed.
• A product can be approved but commercially unavailable.
• A generic applicant must establish the regulatory basis for marketing its product.
• The absence of listed patents does not guarantee that a generic manufacturer will launch.
• Manufacturing economics, market size, controlled-substance compliance, and product liability exposure can prevent commercialization even when patent risk is low.

FDA labeling records have historically associated Soma Compound with carisoprodol and aspirin tablets. The branded product’s commercial relevance has declined as prescriptions migrated toward generic carisoprodol and alternative muscle relaxants. [1][3]

Are there Paragraph IV challenges to carisoprodol and aspirin?

Paragraph IV litigation is not a major current market issue for the legacy combination. The product’s age and lack of meaningful unexpired patent protection reduce the incentive for a conventional Paragraph IV campaign.

A Paragraph IV certification applies when an abbreviated new drug application challenges a listed patent as invalid, unenforceable, or not infringed. For a product with no material unexpired Orange Book patents, the central regulatory question is generally approval eligibility rather than patent litigation.

The absence of current Paragraph IV activity does not mean the product is commercially attractive. Generic developers evaluate expected volume, pricing, manufacturing complexity, controlled-substance obligations, and the availability of more profitable carisoprodol products before investing in a combination product.

Which companies are challenging or competing with carisoprodol and aspirin?

The product competes primarily with generic and therapeutic alternatives rather than branded patent challengers.

Direct competitors

Direct competition includes generic carisoprodol tablets, generally marketed without aspirin. Carisoprodol monotherapy is easier to prescribe and dose because it avoids aspirin-related gastrointestinal bleeding, renal considerations, allergy concerns, and interactions with anticoagulants.

The combination also competes with carisoprodol and codeine products, although those products face greater controlled-substance and opioid-related scrutiny.

Therapeutic substitutes

Product or class	Competitive advantage
Cyclobenzaprine	Broad generic availability and familiar prescribing profile
Methocarbamol	Lower controlled-substance concern in many markets
Tizanidine	Established alternative for muscle spasm
Baclofen	Useful in selected spasticity indications
NSAIDs	Low-cost analgesic and anti-inflammatory treatment
Acetaminophen	Widely available analgesic without aspirin-specific bleeding risk
Physical therapy	Guideline-supported non-drug treatment for many musculoskeletal conditions

The competitive market is fragmented. No single alternative fully replaces the combination across all prescribers, but the combined pressure from multiple low-cost alternatives limits pricing power.

How strong is the patent estate for carisoprodol and aspirin?

The patent estate is weak to nonexistent for current commercial purposes.

Patent-estate category	Current assessment
Active composition patent	No material protection
Active formulation patent	No material protection identified
Active method-of-use patent	No material protection identified
Regulatory exclusivity	Expired legacy exclusivity
Data exclusivity	Not commercially relevant for this old product
Patent litigation leverage	Low
Generic entry barrier	Primarily regulatory and economic

The product’s defensibility would depend on factors outside patent law, including reliable supply, manufacturing cost, wholesaler access, controlled-substance compliance, and physician familiarity.

What is the FDA regulatory status of carisoprodol and aspirin?

Carisoprodol and aspirin is a prescription product regulated under the FDA’s legacy drug approval framework. Carisoprodol is a federally controlled substance. The Drug Enforcement Administration placed carisoprodol in Schedule IV effective January 11, 2012, citing abuse, dependence, and diversion concerns. [4]

The regulatory profile affects commercial operations in several ways:

1. Manufacturers must maintain controlled-substance compliance systems.
2. Distributors and pharmacies face recordkeeping and dispensing obligations.
3. Prescribers may use prescription-monitoring databases depending on state requirements.
4. Product liability risk is higher than for an ordinary noncontrolled analgesic.
5. Payers and health systems may prefer alternatives with lower abuse potential.

Aspirin introduces a separate risk profile, including gastrointestinal bleeding, hypersensitivity, renal effects, and interactions with anticoagulants and antiplatelet drugs. Those risks can make the fixed-dose combination less attractive than prescribing carisoprodol and analgesic therapy separately.

What manufacturing and intellectual-property barriers exist?

Manufacturing barriers are moderate but not technologically difficult. The product uses conventional oral-tablet technology and does not require biologic production, sterile filling, complex delivery devices, or specialized cold-chain logistics.

The principal barriers are:

• Validated production of a controlled-substance tablet
• Secure sourcing and inventory control for carisoprodol
• Compliance with DEA requirements
• Content uniformity and dissolution testing
• Stability and packaging controls
• Pharmacovigilance for dependence, sedation, bleeding, and hypersensitivity
• Commercial scale sufficient to offset low unit prices
• Product-liability management

A manufacturer could obtain a strategic advantage through reliable supply or a differentiated package, but those advantages would be operational rather than patent-based.

How has the financial trajectory changed?

The financial trajectory follows the standard pattern for an aging prescription combination:

1. Early branded growth followed clinical adoption of the Soma franchise.
2. Generic competition reduced price and market share.
3. Carisoprodol safety scrutiny constrained prescribing.
4. Fixed-dose aspirin exposure reduced clinical flexibility.
5. Prescribing shifted toward generic carisoprodol and alternative muscle relaxants.
6. Current value is concentrated in low-margin generic volume rather than brand pricing.

Public sources do not provide a reliable standalone revenue series for carisoprodol and aspirin. Manufacturers generally report the product within broader pharmaceutical portfolios, and historical brand ownership and marketing arrangements changed over time. Product-specific revenue should therefore not be inferred from corporate segment results.

Revenue exposure by business model

Business model	Financial outlook
Branded Soma Compound	Limited pricing power and declining strategic value
Generic fixed-dose combination	Low unit economics; viable only with efficient production
Generic carisoprodol monotherapy	Larger addressable market and simpler prescribing
Reformulated product	Potential differentiation, but requires clinical and regulatory investment
Licensing rights	Limited value without reliable distribution or a differentiated formulation

The most important commercial variable is not patent expiry. It is whether prescription demand is sufficient to support continued production after manufacturing, compliance, distribution, and liability costs.

What generic launch risks exist for carisoprodol and aspirin?

Generic entry risk is technically high and legally low.

Legal risk

Patent litigation risk is low because the product lacks a meaningful current patent estate. A generic applicant is unlikely to face the type of injunction threat associated with an active branded patent portfolio.

Regulatory risk

Regulatory risk remains material. The applicant must demonstrate pharmaceutical equivalence, bioequivalence where applicable, manufacturing quality, labeling compliance, and controlled-substance controls.

Commercial risk

Commercial risk is higher than legal risk. A launch could produce limited returns because:

• The patient population is narrow.
• Physicians can prescribe generic carisoprodol separately.
• Aspirin is inexpensive and widely available.
• Payers may not reimburse a fixed-dose combination at a premium.
• Competitors can reduce prices rapidly.
• The product may face discontinuation if volume falls below manufacturing thresholds.

A plausible launch scenario is a low-price generic introduced by a manufacturer already producing carisoprodol tablets. A premium launch is unlikely without a clinically differentiated formulation or a distribution advantage.

Does carisoprodol and aspirin face biosimilar risk?

No. Carisoprodol and aspirin is a small-molecule drug, not a biologic. Biosimilar approval under the Public Health Service Act does not apply.

The relevant competition is conventional generic-drug competition under the Federal Food, Drug, and Cosmetic Act. The market risk comes from abbreviated new drug applications, therapeutic substitution, and payer formulary decisions rather than biosimilar interchangeability. [5]

What litigation and settlement agreements affect the product?

No major current patent litigation or high-value settlement agreement is central to the commercial outlook for carisoprodol and aspirin. The legacy product’s age, generic status, and limited patent protection reduce the likelihood of a branded-generic settlement structure.

The more relevant legal exposure concerns:

• Controlled-substance distribution
• Alleged diversion or inadequate monitoring
• Product-liability claims involving dependence or impairment
• Aspirin-related bleeding events
• Manufacturing and labeling compliance
• State opioid and controlled-substance enforcement regimes

These risks can affect insurance costs and commercial willingness to maintain the product even when patent risk is minimal.

How does carisoprodol and aspirin compare with carisoprodol alone?

Carisoprodol monotherapy has the stronger commercial position.

Factor	Carisoprodol and aspirin	Carisoprodol alone
Dosing flexibility	Lower	Higher
Aspirin-related bleeding risk	Present	Absent
Prescribing convenience	Fixed analgesic component	Analgesic can be selected separately
Addressable market	Narrower	Broader
Generic competition	Limited but price-sensitive	More established
Patent protection	None of commercial significance	None of commercial significance
Commercial outlook	Mature and constrained	Larger but exposed to safety scrutiny

The combination can be useful when the prescriber wants both components in a single tablet. Its fixed dose becomes a disadvantage when the patient has aspirin contraindications or requires a different analgesic strategy.

Key Takeaways

• Carisoprodol and aspirin is a legacy prescription combination historically marketed as Soma Compound.
• Its core patent and regulatory exclusivity periods expired decades ago.
• No material active Orange Book patent estate currently protects the legacy product.
• Paragraph IV litigation and settlement risk are low.
• Carisoprodol’s Schedule IV status has increased compliance, diversion, and liability costs.
• The product competes against generic carisoprodol, other muscle relaxants, NSAIDs, acetaminophen, and physical therapy.
• Carisoprodol monotherapy has a stronger commercial position because it offers greater dosing flexibility.
• Publicly reported product-specific revenue is not available in a reliable form.
• Financial value is likely low and volume-dependent, with limited pricing power.
• Generic launch barriers are primarily regulatory, operational, and economic rather than patent-based.

FAQs About Carisoprodol and Aspirin

Is Soma Compound still commercially available?

Soma Compound has a legacy FDA approval history, but commercial availability can vary by manufacturer, wholesaler, and market. Generic carisoprodol is more widely recognized than the fixed-dose carisoprodol-and-aspirin combination.

Is carisoprodol and aspirin an opioid?

No. Carisoprodol is a centrally acting skeletal muscle relaxant, and aspirin is a salicylate analgesic. Carisoprodol is federally classified as a Schedule IV controlled substance, but it is not an opioid.

Can a company obtain new patents on carisoprodol and aspirin?

A company could seek patents covering a genuinely novel formulation, dosing regimen, delivery system, or abuse-deterrent technology. It could not obtain a new composition patent over the old active ingredients merely by commercializing the existing tablet.

Why might a generic version not be launched despite expired patents?

Low expected volume, limited pricing, controlled-substance compliance costs, product-liability exposure, and competition from generic carisoprodol can make the product commercially unattractive.

What is the principal clinical weakness of the fixed-dose combination?

The fixed aspirin dose reduces prescribing flexibility and exposes patients to aspirin-related bleeding, gastrointestinal, renal, and drug-interaction risks that would not arise from carisoprodol monotherapy.

References

1. U.S. Food and Drug Administration. (2011). Soma Compound: Carisoprodol and aspirin tablet prescribing information. FDA Drugs@FDA.

2. U.S. Food and Drug Administration. (2025). Approved drug products with therapeutic equivalence evaluations, 45th edition: Orange Book. FDA.

3. National Library of Medicine. (n.d.). DailyMed: Carisoprodol and aspirin tablet labeling. U.S. National Library of Medicine.

4. Drug Enforcement Administration. (2011). Schedules of controlled substances: Placement of carisoprodol into Schedule IV. 76 Fed. Reg. 77330.

5. U.S. Food and Drug Administration. (2024). Abbreviated new drug application process and generic drug approval. FDA.