Acetaminophen; pentazocine hydrochloride - Generic Drug Details

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What are the generic sources for acetaminophen; pentazocine hydrochloride and what is the scope of freedom to operate?

Acetaminophen; pentazocine hydrochloride is the generic ingredient in two branded drugs marketed by Gavis Pharms, Watson Labs, and Sanofi Aventis Us, and is included in three NDAs. Additional information is available in the individual branded drug profile pages.

Summary for acetaminophen; pentazocine hydrochloride

US Patents:	0
Tradenames:	2
Applicants:	3
NDAs:	3
DailyMed Link:	acetaminophen; pentazocine hydrochloride at DailyMed

Anatomical Therapeutic Chemical (ATC) Classes for acetaminophen; pentazocine hydrochloride

N02AD	Benzomorphan derivatives
N02A	OPIOIDS
N02	ANALGESICS
N	Nervous system

US Patents and Regulatory Information for acetaminophen; pentazocine hydrochloride

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Exclusivity Expiration
Gavis Pharms	ACETAMINOPHEN AND PENTAZOCINE HYDROCHLORIDE	acetaminophen; pentazocine hydrochloride	TABLET;ORAL	076202-001	Aug 2, 2002		DISCN	No	No
Sanofi Aventis Us	TALACEN	acetaminophen; pentazocine hydrochloride	TABLET;ORAL	018458-001	Sep 23, 1982		DISCN	No	No
Watson Labs	ACETAMINOPHEN AND PENTAZOCINE HYDROCHLORIDE	acetaminophen; pentazocine hydrochloride	TABLET;ORAL	074699-001	Mar 24, 2000		DISCN	No	No

Expired US Patents for acetaminophen; pentazocine hydrochloride

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	Patent No.	Patent Expiration
Sanofi Aventis Us	TALACEN	acetaminophen; pentazocine hydrochloride	TABLET;ORAL	018458-001	Sep 23, 1982

Acetaminophen and Pentazocine Hydrochloride Market Dynamics, Patent Status, and Financial Trajectory

Last updated: November 13, 2026

Acetaminophen and pentazocine hydrochloride is a mature, low-revenue opioid combination marketed primarily as a generic equivalent to Talacen. The product combines 25 mg of pentazocine hydrochloride with 650 mg of acetaminophen per tablet and is indicated for short-term treatment of acute pain when an opioid analgesic is appropriate.[1]

The commercial profile is defined by generic competition, limited prescribing, opioid-control requirements, and the absence of meaningful current patent exclusivity. Public companies generally do not report product-level revenue for this combination. Its financial trajectory is therefore best assessed through regulatory status, manufacturer participation, prescription economics, supply constraints, and competition from other analgesics.

What is acetaminophen and pentazocine hydrochloride?

Acetaminophen and pentazocine hydrochloride is an oral fixed-dose analgesic combining:

Component	Typical tablet strength	Pharmacologic role
Pentazocine hydrochloride	Equivalent to 25 mg pentazocine	Opioid analgesic
Acetaminophen	650 mg	Non-opioid analgesic and antipyretic

The historical branded product is Talacen. The combination was approved in the United States in 1982 under NDA 018707.[1] The approved label covers short-term relief of acute pain that is severe enough to require an opioid analgesic and for which alternative treatments are inadequate.

Pentazocine is a mixed opioid agonist-antagonist. It has activity at kappa opioid receptors and weaker activity at the mu receptor compared with full mu agonists such as oxycodone or hydrocodone. The product remains subject to opioid warnings, including respiratory depression, dependence, withdrawal, misuse, and potentially fatal overdose.[1]

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

The product is an FDA-approved prescription drug, but its commercial status is predominantly generic rather than branded.

Regulatory attribute	Status
Reference product	Talacen
NDA	018707
Initial U.S. approval	1982
Dosage form	Immediate-release tablet
Typical strength	Pentazocine 25 mg / acetaminophen 650 mg
FDA pathway for competitors	ANDA generic approval
Controlled-substance category	Schedule IV pentazocine product
Biologic status	Not applicable
Current exclusivity profile	No meaningful NCE or market exclusivity remaining

The FDA Orange Book is the principal source for reference-product, patent-listing, and therapeutic-equivalence information.[2] Talacen’s commercial lifecycle is long past the period in which New Chemical Entity exclusivity, pediatric exclusivity, or brand-led market protection would influence competition.

What patents protect acetaminophen and pentazocine hydrochloride?

No material current patent barrier is associated with the core acetaminophen-pentazocine tablet. The product was introduced more than four decades ago, and any foundational composition or formulation patents would have expired before the current generic market developed.

Patent estate

Patent category	Current commercial relevance
Core combination patent	Expired or no longer commercially blocking
Pentazocine active-ingredient patents	Expired
Acetaminophen patents	Expired
Immediate-release tablet patents	Expired or irrelevant to generic entry
Method-of-use patents	No material blocking protection identified
Manufacturing patents	No evident barrier to routine tablet manufacture
Orange Book-listed patents	No current patent position that materially delays ANDA entry

The absence of a relevant patent estate means that a prospective manufacturer would not normally need to design around a protected composition, delivery system, or treatment method. The principal barriers are commercial and regulatory rather than intellectual property-based.

When does acetaminophen and pentazocine lose exclusivity?

The product lost meaningful exclusivity decades ago. FDA approval in 1982 placed the product well outside the period of modern small-molecule exclusivity protections. Any NCE exclusivity would have expired in the 1980s, while ordinary U.S. patent terms associated with the original product would have expired no later than the early 2000s in the absence of later-filed, enforceable patents.

The relevant market question is no longer when exclusivity ends. It is whether enough prescription volume remains to support manufacturing, distribution, controlled-substance compliance, and inventory management.

How many patents cover acetaminophen and pentazocine?

The practical answer is zero material blocking patents for the standard immediate-release combination. Any historical patent records associated with pentazocine, acetaminophen, or the Talacen product are not expected to prevent current generic production.

This patent profile differs from newer opioid formulations that may have protection covering abuse-deterrent technology, extended-release delivery, or proprietary abuse-resistance mechanisms. Acetaminophen and pentazocine is an older immediate-release tablet with no comparable technology layer.

What generic entry risks exist for acetaminophen and pentazocine?

Generic entry risk is already realized rather than pending. The product is exposed to:

• Multiple-source generic competition.
• Low reimbursement ceilings.
• Pharmacy substitution.
• Wholesaler purchasing concentration.
• Controlled-substance quota constraints.
• Low inventory turnover.
• Potential manufacturer exits.
• Substitution by non-opioid analgesics and other opioids.

A Paragraph IV challenge would have limited strategic value because the relevant product is not dependent on an active patent barrier. ANDA applicants would generally pursue ordinary generic approval rather than use Paragraph IV litigation to accelerate entry.

Paragraph IV and litigation exposure

Issue	Assessment
Active patent challenge	No material challenge expected
Paragraph IV value	Low
Patent litigation risk	Low
ANDA approval risk	Primarily manufacturing, bioequivalence, and supply-related
Regulatory delay risk	Greater than patent delay risk
Settlement risk	Minimal because no meaningful blocking patent position remains

The more important litigation risks concern opioid marketing, controlled-substance compliance, labeling, product liability, and alleged failure to manage diversion. Those risks are separate from patent litigation.

What formulations are protected by acetaminophen and pentazocine patents?

The commercial product is an immediate-release tablet. There is no evident active formulation patent protecting an extended-release, abuse-deterrent, transdermal, injectable, or implantable version of the combination.

This limits pricing power. A manufacturer cannot rely on a proprietary delivery system to justify a premium over standard generic tablets. Any product differentiation would likely come from supply reliability, packaging, wholesaler relationships, or contracting rather than formulation exclusivity.

Manufacturing and intellectual-property barriers

Manufacturing requirements are conventional for a solid oral dosage form. The product requires:

1. Control of pentazocine content and uniformity.
2. Acetaminophen assay and impurity control.
3. Tablet compression and dissolution testing.
4. Stability testing.
5. Controlled-substance security and recordkeeping.
6. Compliance with current good manufacturing practice requirements.

Pentazocine procurement and distribution can be more difficult than ordinary noncontrolled analgesics because manufacturers must comply with Drug Enforcement Administration requirements and applicable production quotas.[3] Those obligations may reduce the number of active suppliers even when no patent prevents entry.

What is the competitive landscape for this drug?

Acetaminophen and pentazocine competes in a shrinking segment of the oral acute-pain market.

Competitor	Competitive position
Acetaminophen alone	Preferred for mild or moderate pain without opioid exposure
Ibuprofen and other NSAIDs	Strong substitute where anti-inflammatory treatment is appropriate
Hydrocodone/acetaminophen	More familiar full-opioid alternative, generally Schedule II
Oxycodone/acetaminophen	Higher-potency opioid alternative, generally Schedule II
Tramadol/acetaminophen	Alternative combination with different opioid and serotonergic risks
Pentazocine/naloxone	Related product designed to reduce injection misuse
Codeine/acetaminophen	Older opioid combination with variable metabolism and declining use

Pentazocine’s Schedule IV status can be commercially advantageous relative to Schedule II products in some prescribing and dispensing contexts. Its mixed agonist-antagonist pharmacology can also limit its use in patients receiving full opioid agonists because of possible precipitated withdrawal or reduced analgesic effect.[1]

The product’s disadvantages include lower familiarity, opioid-related safety concerns, limited clinical differentiation, and competition from non-opioid pain protocols.

What is the financial trajectory of acetaminophen and pentazocine?

The financial trajectory is mature-to-declining, with limited opportunity for branded price expansion.

Revenue profile

No major manufacturer publicly discloses separate revenue for acetaminophen and pentazocine. The combination is generally included within broader generic, hospital, or pain-management revenue categories. Public financial filings therefore cannot support a reliable standalone sales estimate.

The economics are likely characterized by:

• Low unit prices.
• Low absolute revenue per manufacturer.
• High sensitivity to manufacturing interruptions.
• Limited marketing expenditure.
• Contract and wholesaler-driven purchasing.
• Greater profitability during supply shortages than during normal competition.
• Declining or stagnant demand as opioid prescribing becomes more restrictive.

The product can remain commercially viable despite modest prescription volume if only a small number of manufacturers maintain supply. That does not imply strong brand value or durable pricing power. It reflects the economics of a narrow generic market in which supplier exits can temporarily tighten availability.

Revenue exposure by market segment

Segment	Revenue outlook
Branded product	Minimal
Retail generic prescriptions	Low and mature
Hospital and institutional use	Limited, dependent on formulary preference
Specialty or biologic use	None
Licensing revenue	No significant public evidence
Patent monetization	None expected
Shortage-driven upside	Possible but temporary

Which companies are challenging or supplying the product?

The market is supplied through FDA-approved generic manufacturers and labelers rather than through a single dominant innovator. Manufacturer participation can change as companies discontinue older products, transfer applications, or retain approval without actively marketing the drug.

FDA’s National Drug Code Directory and Drugs@FDA records are the relevant sources for identifying active product listings and application holders.[4] Product-level manufacturer presence should be distinguished from actual commercial supply because an NDC listing does not necessarily establish meaningful market availability.

There is no major publicly disclosed licensing transaction associated with the current generic market. The product lacks the patent or clinical differentiation that typically supports a high-value licensing deal.

What is the generic launch scenario?

A new generic entrant would face no meaningful patent delay. The likely launch scenario would be:

Launch factor	Expected effect
Patent clearance	Favorable
FDA approval pathway	ANDA
Bioequivalence burden	Standard immediate-release tablet requirements
Pricing	Aggressive because of generic competition
Market access	Dependent on wholesalers and pharmacy contracts
Controlled-substance compliance	Higher than noncontrolled analgesics
Commercial differentiation	Limited
Long-term margin	Vulnerable to price erosion

A new entrant could benefit from supply shortages or manufacturer withdrawals, but a durable premium would be difficult to sustain. The product does not offer a protected formulation, a novel indication, or a large untreated patient population.

What is the biosimilar risk for acetaminophen and pentazocine?

There is no biosimilar risk. Acetaminophen and pentazocine is a chemically synthesized small-molecule drug, not a biologic. Competition occurs through generic-drug pathways under Section 505(j) of the Federal Food, Drug, and Cosmetic Act rather than through the biosimilar pathway under the Public Health Service Act.

The relevant competitive risk is generic substitution, not biosimilar entry.

How does acetaminophen and pentazocine compare with Talwin NX?

Talwin NX contains pentazocine and naloxone, while acetaminophen and pentazocine contains acetaminophen.

Attribute	Acetaminophen/pentazocine	Talwin NX
Non-opioid component	Acetaminophen	Naloxone
Primary design	Analgesic combination	Pentazocine product with naloxone
Acetaminophen toxicity concern	Present	Absent
Opioid withdrawal interaction	Present	Present
Patent profile	Mature and generic	Mature and generic
Commercial differentiation	Limited	Greater historical differentiation from naloxone

Talwin NX was developed with naloxone to reduce misuse through injection. The acetaminophen combination instead adds a conventional non-opioid analgesic, which creates a cumulative acetaminophen exposure issue when patients use other acetaminophen-containing products.

What regulatory risks affect future sales?

FDA opioid labeling emphasizes serious risks associated with addiction, misuse, abuse, respiratory depression, accidental ingestion, and interaction with benzodiazepines or other central nervous system depressants.[5] These risks can reduce prescribing and increase institutional restrictions.

The key regulatory pressures are:

• Opioid prescribing limits.
• State-level controlled-substance requirements.
• Prescription drug monitoring programs.
• DEA manufacturing and distribution controls.
• FDA inspection and current good manufacturing practice compliance.
• Acetaminophen dose-management requirements.
• Product liability and diversion claims.

These pressures are more relevant to future demand than patent expiration.

Key Takeaways

• Acetaminophen and pentazocine hydrochloride is a mature generic opioid combination, historically marketed as Talacen.
• The reference product was approved in the United States in 1982 under NDA 018707.
• No material current patent or regulatory exclusivity barrier is expected to restrict generic entry.
• Paragraph IV litigation and patent settlement risk are low.
• The product has no biosimilar exposure because it is a small-molecule drug.
• Revenue is not publicly reported at the product level and is likely low relative to major opioid combinations.
• Market value depends on supply continuity, controlled-substance compliance, and generic competition.
• The long-term financial trajectory is mature-to-declining, with temporary upside possible during shortages.
• Manufacturing and DEA requirements are more significant barriers than intellectual property.
• Competitive pressure comes from acetaminophen, NSAIDs, hydrocodone/acetaminophen, oxycodone/acetaminophen, tramadol combinations, and pentazocine/naloxone.

FAQs

Is acetaminophen and pentazocine still available in the United States?

The combination has an established FDA approval and may be available through generic product listings, although commercial availability can vary by manufacturer, wholesaler, and controlled-substance supply conditions.

Is pentazocine with acetaminophen a Schedule II opioid?

No. Pentazocine products are federally classified as Schedule IV controlled substances, although state requirements and product-specific handling obligations still apply.[3]

Can a company obtain a new patent on a pentazocine and acetaminophen tablet?

A company could seek a patent for a genuinely novel formulation, manufacturing process, or delivery system. A routine immediate-release tablet would face substantial validity and non-obviousness challenges and would not recreate the historical exclusivity of Talacen.

Does acetaminophen and pentazocine have abuse-deterrent labeling?

The conventional immediate-release combination should not be treated as an abuse-deterrent opioid formulation unless a specific FDA-approved product label states otherwise.

Is Talacen a high-value licensing opportunity?

The standard Talacen-type combination is unlikely to support a high-value licensing transaction because it has no material patent estate, no biologic exclusivity, and limited product differentiation. A transaction would be more likely to involve manufacturing rights, supply contracts, or a broader generic portfolio.

References

1. U.S. Food and Drug Administration. (n.d.). Talacen: Pentazocine hydrochloride and acetaminophen prescribing information. NDA 018707.

2. U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations: Orange Book. https://www.fda.gov/drugs/drug-approvals-and-databases/approved-drug-products-therapeutic-equivalence-evaluations-orange-book

3. U.S. Drug Enforcement Administration. (2024). Controlled substance schedules. https://www.dea.gov/drug-information/drug-scheduling

4. U.S. Food and Drug Administration. (2024). Drugs@FDA and National Drug Code Directory. https://www.fda.gov/drugs

5. U.S. Food and Drug Administration. (2023). Opioid analgesic prescribing information and boxed warning updates. https://www.fda.gov/drugs/information-drug-class/opioid-analgesic-risk-evaluation-and-mitigation-strategy-rem s