List of Excipients in Branded Drug HYDROCODONE/APAP

Generic Drugs Containing HYDROCODONE/APAP

Company	Ingredient	NDC	Excipient
PharmPak Inc	hydrocodone bitartrate, acetaminophen	54348-066	CELLULOSE, MICROCRYSTALLINE
PharmPak Inc	hydrocodone bitartrate, acetaminophen	54348-066	CROSPOVIDONE
PharmPak Inc	hydrocodone bitartrate, acetaminophen	54348-066	MAGNESIUM STEARATE

What are the Most Frequently-Used Excipients in HYDROCODONE/APAP?

# Of NDCs	Excipient
5	CELLULOSE, MICROCRYSTALLINE
2	CROSCARMELLOSE SODIUM
3	CROSPOVIDONE

Last updated: August 10, 2026

Hydrocodone/APAP is a mature, genericized immediate-release opioid combination with limited composition-of-matter protection and substantial regulatory constraints. Commercial value has shifted from molecule ownership to differentiated excipients, dosage-form engineering, abuse-deterrence, supply reliability, and lower-acetaminophen formulations. The strongest opportunities are compliant oral dosage forms that improve swallowability, dose flexibility, stability, tamper resistance, or manufacturing economics without increasing opioid exposure.

Hydrocodone/APAP Excipient Strategy and Commercial Opportunities

What is the commercial profile of hydrocodone/APAP?

Hydrocodone/APAP combines hydrocodone, a semisynthetic opioid agonist, with acetaminophen, also known as paracetamol. It is marketed in the United States as immediate-release tablets, capsules, oral solutions, and related dosage forms under brand names including Vicodin, Norco, and Lortab, alongside numerous generic products.

The principal commercial strengths are established clinical use, broad prescriber familiarity, and multiple generic manufacturers. The principal constraints are Schedule II opioid controls, opioid-prescribing restrictions, acetaminophen hepatotoxicity, mature generic competition, and limited ability to claim broad patent protection around the active ingredients.

Attribute	Commercial assessment
Active ingredients	Hydrocodone bitartrate or hydrocodone equivalent plus acetaminophen
Main U.S. dosage forms	Immediate-release tablets, capsules, oral solution, and elixir-type products
Typical APAP strengths	300 mg or 325 mg per dosage unit in current common products
Controlled-substance status	Schedule II in the United States
Primary therapeutic use	Short-term treatment of acute pain when an opioid is appropriate
Core regulatory pathway	ANDA for generic products; NDA or 505(b)(2) for differentiated products
Patent position	Mature active-ingredient and basic-combination protection; product-specific patents may remain relevant
Main safety issue	Opioid respiratory depression and acetaminophen-related liver injury
Main commercial differentiators	Excipients, dosage form, abuse deterrence, dose flexibility, supply, and device compatibility

The FDA has required labeling that limits total daily acetaminophen exposure and warns about severe liver injury. Prescribers and patients may receive acetaminophen from multiple products, creating a cumulative-dose risk that is separate from hydrocodone exposure.[1]

What excipient strategies are available for hydrocodone/APAP?

Excipient selection can support manufacturability, dose uniformity, dissolution, patient acceptability, stability, and product differentiation. It cannot eliminate the pharmacologic risks of hydrocodone or acetaminophen.

Immediate-release tablet strategy

The most practical generic strategy is a conventional compressed tablet using excipients such as:

• Microcrystalline cellulose for compactability and tablet robustness
• Lactose, mannitol, or dibasic calcium phosphate as fillers
• Croscarmellose sodium, sodium starch glycolate, or crospovidone as disintegrants
• Povidone or copovidone as binders
• Colloidal silicon dioxide as a glidant
• Magnesium stearate or sodium stearyl fumarate as lubricants
• Film-coating polymers such as hypromellose, polyethylene glycol, and titanium dioxide, subject to applicable regulatory requirements

The formulation objective is rapid and reproducible release rather than prolonged retention or modified pharmacokinetics. Excessive hydrophobic lubricant, overcompression, or dense coating can delay dissolution and complicate bioequivalence.

For an ANDA, formulation changes must remain within the product-specific expectations for qualitative and quantitative composition, dissolution, and bioequivalence. A novel excipient or materially different excipient level can increase development and regulatory risk.

Low-dose and dose-flexibility strategy

Current hydrocodone/APAP products commonly use 300 mg or 325 mg acetaminophen per unit. A commercially relevant strategy is to offer multiple strengths that reduce unnecessary acetaminophen exposure while preserving clinically useful hydrocodone dosing.

Potential formats include:

• Lower-APAP tablets for patients requiring opioid analgesia but approaching acetaminophen limits
• Scored tablets for dose flexibility, where dose uniformity and splitting performance support the claim
• Multiple hydrocodone-to-APAP ratios
• Unit-dose packaging that reduces medication errors
• Oral solutions with calibrated dosing devices

The principal barrier is clinical and regulatory, not purely formulation-related. A lower-APAP product must demonstrate that the revised ratio offers a meaningful prescribing or safety advantage without encouraging dose escalation or inappropriate use.

Oral solution and liquid excipient strategy

Liquid products can serve pediatric, geriatric, dysphagic, hospice, and post-operative populations, although opioid use in children is highly restricted and requires careful labeling. The formulation must address:

• Hydrocodone and acetaminophen solubility
• pH control
• Chemical stability
• Flavor masking
• Microbial control
• Container-closure compatibility
• Accurate dose measurement
• Sedimentation or precipitation risk
• Alcohol and sugar content

Common platform choices include purified water, glycerin, sorbitol, propylene glycol, buffering agents, sweeteners, flavors, preservatives, and viscosity modifiers. Each excipient creates tradeoffs. Sorbitol can cause gastrointestinal effects. Sugar increases concern for dental and metabolic populations. Preservatives may create tolerability and labeling considerations. Alcohol can create pediatric, geriatric, and controlled-substance handling concerns.

An oral solution with a robust dosing syringe, tamper-evident packaging, and clear concentration labeling can create more commercial value than a minor flavor change.

What formulations are protected by hydrocodone/APAP patents?

No single patent generally protects all hydrocodone/APAP products. Patent scope is product-specific and may cover:

• A particular hydrocodone salt or ratio
• A tablet composition
• A coating or multiparticulate structure
• A liquid formulation
• A method of treating pain
• An abuse-deterrent dosage form
• A manufacturing process
• A packaging configuration

The early branded products were protected primarily through product, formulation, and regulatory exclusivity mechanisms rather than a currently active, broad monopoly covering the entire hydrocodone/APAP category.

What is the Orange Book status of hydrocodone/APAP?

Orange Book listings must be reviewed by product and application number. Hydrocodone/APAP has multiple approved applications and dosage forms, and listed patents can differ among reference products. Basic generic products generally rely on expired or nonblocking protections, while specialized products may have active formulation or method-of-use listings.

A commercial diligence review should distinguish:

1. The reference listed drug.
2. The approved strength and dosage form.
3. Active Orange Book patents.
4. Pediatric exclusivity or other regulatory exclusivity.
5. Paragraph IV certifications.
6. Litigation under the Hatch-Waxman framework.
7. Whether a listed patent actually reads on the proposed product.

FDA Orange Book records and individual labeling should control the current analysis.[2]

When does hydrocodone/APAP lose exclusivity?

The principal hydrocodone/APAP brands lost practical exclusivity years ago, and generic competition is established. Exact patent expiration dates depend on the specific branded application and listed patent. There is no single expiration date for the entire category.

For a new product, the relevant protection could come from:

Protection type	Typical relevance
Active-ingredient patent	Usually limited for this mature combination
Formulation patent	Most relevant for novel excipient systems or dosage forms
Abuse-deterrent patent	Relevant if the product demonstrates meaningful manipulation resistance
Manufacturing patent	Potentially useful where process differences are difficult to replicate
Method-of-use patent	Narrow and vulnerable if the use is already established
New chemical entity exclusivity	Generally unavailable for an old combination
505(b)(2) exclusivity	Possible for a materially differentiated reformulation, depending on approval basis
Orphan exclusivity	Not ordinarily applicable to routine acute pain use

An improved formulation may obtain patents, but patentability requires more than substituting one conventional excipient for another. The applicant would need a defensible technical effect, such as unexpected dissolution, stability, abuse-deterrence, dose uniformity, or pharmacokinetic performance.

How can abuse-deterrent excipients create commercial opportunity?

The FDA recognizes several abuse-deterrence categories, including physical or chemical barriers, agonist-antagonist combinations, aversion, delivery-system controls, and combinations of technologies.[3]

For hydrocodone/APAP, potential formulation approaches include:

• High-hardness matrices that resist crushing
• Gelling systems that make extraction difficult
• Sequestered hydrocodone in a polymeric or multiparticulate structure
• Irritant or aversive components, subject to safety and regulatory review
• Coatings that resist powderization or solvent extraction
• Packaging that limits diversion and supports controlled dispensing

A key commercial limitation is that an abuse-deterrent claim does not mean abuse is impossible. FDA labeling distinguishes laboratory manipulation resistance from reduced abuse in real-world settings. The formulation may require comparative in vitro testing, pharmacokinetic studies, human abuse-potential studies, and postmarketing surveillance depending on the claim and development pathway.[3]

An abuse-deterrent hydrocodone/APAP product also faces a strategic problem: the product contains acetaminophen. Manipulation that concentrates or extracts hydrocodone may also change acetaminophen exposure, creating an additional safety and toxicology burden.

Which companies are challenging or competing with hydrocodone/APAP products?

Competition is fragmented across generic manufacturers, branded opioid companies, contract manufacturers, and specialty pharmaceutical developers. Major generic manufacturers have historically marketed hydrocodone/APAP products, including companies such as Mallinckrodt, Amneal, Hikma, Teva, and others, depending on the specific product, period, and market status.

The relevant competitive set includes:

• Conventional generic tablets
• Generic capsules
• Oral solutions
• Branded or authorized-generic products
• Abuse-deterrent hydrocodone products without acetaminophen
• Non-opioid analgesics such as NSAIDs and acetaminophen-only products
• Fixed-dose combinations involving other analgesics

Zohydro ER and Hysingla ER are extended-release hydrocodone products without acetaminophen. They are not direct hydrocodone/APAP substitutes because they have different pharmacokinetics, labeling, abuse-deterrence considerations, and clinical use.[4][5]

What FDA regulatory pathway applies to a differentiated hydrocodone/APAP product?

ANDA pathway

An ANDA is the most efficient route for a conventional generic that matches the reference product in dosage form, strength, route of administration, and applicable performance characteristics. The sponsor must address bioequivalence, chemistry, manufacturing, controls, labeling, and controlled-substance requirements.

This route offers limited room for commercial differentiation. Excipients may differ within acceptable boundaries, but the final product must satisfy the reference-product equivalence framework.

505(b)(2) pathway

A 505(b)(2) application can support a reformulated or otherwise modified product where some safety or efficacy information derives from previously approved products. Potential 505(b)(2) concepts include:

• Novel dosage forms
• Improved liquid formulations
• New delivery systems
• Different hydrocodone/APAP ratios
• Abuse-deterrent products
• New administration routes, although route changes raise substantial development risk

The sponsor must establish that the product’s differences are clinically and regulatorily meaningful. A 505(b)(2) application does not automatically avoid patent disputes or create broad market exclusivity.

Hydrocodone products also require compliance with Drug Enforcement Administration controls, quotas, security, recordkeeping, distribution monitoring, and postmarketing obligations.[6]

What generic entry risks exist for hydrocodone/APAP?

Generic entry risk is high for conventional immediate-release products because:

• The active ingredients are old and widely characterized.
• Multiple manufacturers have established manufacturing capabilities.
• Clinical demand is large but mature.
• Formulation technology is generally accessible.
• Physicians and pharmacies are familiar with generic substitution.
• Basic excipient patents are unlikely to block the field.

Risk is lower for a genuinely differentiated formulation with active patents, difficult-to-reproduce process controls, or a meaningful regulatory designation. Even then, a patent owner must assess Paragraph IV challenges, design-arounds, ANDA timing, and the economic willingness of generic companies to litigate.

How strong is the patent estate for a new hydrocodone/APAP formulation?

Patent strength depends on technical specificity and commercial blocking power.

Patent characteristic	Strength assessment
Broad claim to hydrocodone plus acetaminophen	Weak for a mature combination
Narrow excipient substitution	Usually weak unless tied to an unexpected result
Defined dissolution profile	Moderate if reproducible and clinically relevant
Abuse-deterrent matrix	Potentially strong if supported by robust testing
Manufacturing process with difficult scale-up	Moderate to strong if competitors cannot design around it
Packaging-only claims	Usually narrow and easy to work around
Method-of-use claim for routine acute pain	Vulnerable because of established use
Novel liquid stability system	Moderate if supported by comparative data
Lower-APAP ratio	Potentially useful, but clinical value must be demonstrated

The strongest estate would combine formulation claims, process claims, dissolution or performance limitations, and method-of-use claims. Reliance on a single narrow excipient claim creates design-around risk.

What licensing deals and manufacturing barriers matter?

Publicly visible licensing activity is more likely around opioid technology platforms, abuse-deterrent systems, controlled-release technology, or manufacturing assets than around conventional hydrocodone/APAP tablets. A license may provide access to:

• Polymer matrices
• Sequestration technology
• Tamper-resistant coatings
• Multiparticulate manufacturing
• High-containment opioid production
• Controlled-substance distribution infrastructure
• FDA-ready analytical methods and technical packages

Manufacturing barriers include controlled-substance quotas, API sourcing, validated segregation, theft prevention, reconciliation, batch release testing, and supply-chain compliance. Acetaminophen adds blend uniformity, impurity, dissolution, and stability requirements.

A formulation that requires specialized hot-melt extrusion, multiparticulate coating, or solvent recovery may create a practical barrier even when patent protection is moderate. That barrier can support licensing or contract-manufacturing revenue.

What commercial opportunities remain in hydrocodone/APAP?

The most credible opportunities are incremental and execution-driven.

Lower-acetaminophen products

A lower-APAP formulation could address cumulative acetaminophen exposure. The commercial case depends on prescriber adoption, payer treatment, labeling, and evidence that the product reduces risk without increasing opioid consumption.

Patient-friendly dosage forms

Potential niches include:

• Smaller tablets
• Orally disintegrating tablets
• Easy-swallow capsules
• Sprinkle-compatible multiparticulates
• Calibrated oral solutions
• Unit-dose packaging

Orally disintegrating products require careful control of taste, friability, dose uniformity, and rapid disintegration. They also create diversion concerns because a dosage form that dissolves readily may be easier to misuse unless its design addresses that risk.

Tamper-resistant packaging

Calendar packs, unit-dose blister systems, serialized packaging, and pharmacy-dispensing configurations can reduce medication errors and support institutional channels. Packaging claims alone are unlikely to create a durable moat, but packaging can strengthen a broader product proposition.

Supply and channel reliability

Hospitals, surgery centers, long-term-care facilities, and government purchasers may value reliable supply, validated substitutions, and predictable fill rates. For a mature generic, availability can be more commercially decisive than minor formulation differences.

How does hydrocodone/APAP compare with competing analgesics?

Product category	Main advantage	Main commercial weakness
Hydrocodone/APAP	Familiar acute-pain combination	Opioid dependence risk and APAP liver toxicity
Oxycodone/APAP	Strong analgesic familiarity	Similar opioid and APAP risks
Codeine/APAP	Lower-potency historical option	Variable metabolism and weaker analgesia
Tramadol/APAP	Different opioid profile	Seizure, serotonin, and variable-response concerns
NSAID products	No opioid dependence risk	Gastrointestinal, renal, and cardiovascular risks
Acetaminophen alone	Broad access and lower abuse risk	Limited efficacy for severe pain
Hydrocodone extended release	Long-acting opioid delivery	Not interchangeable with immediate-release hydrocodone/APAP

The strongest substitute pressure comes from non-opioid multimodal pain management, not only from another opioid combination. FDA communications and clinical practice increasingly emphasize opioid stewardship and the lowest effective dose for the shortest appropriate duration.[1][7]

What revenue exposure exists for manufacturers?

Revenue exposure is highest for manufacturers with:

• Large hydrocodone/APAP prescription volumes
• Dependence on a small number of opioid products
• Limited non-opioid portfolio diversification
• Exposure to quota reductions or supply interruptions
• Active litigation or compliance remediation
• Wholesale concentration

The market is mature and price-sensitive. A manufacturer generally needs scale, low-cost production, dependable API access, and broad pharmacy distribution. Premium pricing requires a credible product distinction, such as abuse deterrence, improved dosing accuracy, institutional packaging, or a clinically relevant APAP reduction.

Key Takeaways

• Hydrocodone/APAP is a mature generic market with high conventional generic-entry risk.
• The main commercial opportunity is product differentiation, not broad active-ingredient exclusivity.
• Excipients can improve dissolution, stability, taste, tablet performance, and dose accuracy.
• Lower-acetaminophen ratios, patient-friendly dosage forms, calibrated liquids, and tamper-resistant packaging are the most credible opportunity areas.
• Abuse-deterrent formulations may support patent and regulatory differentiation but require substantial evidence.
• A conventional excipient substitution is unlikely to create a strong patent position without unexpected technical results.
• Orange Book, Paragraph IV, and litigation analysis must be performed by specific reference product and application number.
• Manufacturing, controlled-substance compliance, supply reliability, and distribution controls are material competitive barriers.
• Non-opioid analgesics are the principal long-term competitive threat to hydrocodone/APAP demand.

FAQs

Can a new excipient create market exclusivity for hydrocodone/APAP?

Yes, but only if the excipient system supports patentable claims and a meaningful technical effect. A routine substitution of one filler, binder, or disintegrant for another usually has limited exclusionary value.

Is a lower-acetaminophen hydrocodone product commercially attractive?

Potentially. The product could address cumulative acetaminophen exposure, but commercial success depends on clinical positioning, labeling, payer acceptance, and evidence that prescribers do not compensate with higher opioid dosing.

Are hydrocodone/APAP tablets eligible for abuse-deterrent labeling?

Only a product supported by the applicable FDA abuse-deterrence evidence and labeling review can make an abuse-deterrent claim. Conventional hydrocodone/APAP tablets do not receive that designation merely because they are difficult to crush.

Does hydrocodone/APAP have biosimilar competition?

No. Hydrocodone and acetaminophen are small-molecule active ingredients. Competition occurs through generic drug applications, not the biosimilar pathway.

What is the most defensible patent strategy for a new hydrocodone/APAP product?

A layered strategy combining composition claims, measurable dissolution or abuse-deterrence performance, manufacturing-process claims, and narrowly tailored method-of-use claims is more defensible than a single claim directed to a conventional excipient change.

References

1. U.S. Food and Drug Administration. (2011). FDA drug safety communication: Prescription acetaminophen products to be limited to 325 mg per dosage unit; boxed warning will highlight potential for severe liver failure.
2. U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations: Orange Book.
3. U.S. Food and Drug Administration. (2015). Guidance for industry: Abuse-deterrent opioids: Evaluation and labeling.
4. U.S. Food and Drug Administration. (2013). Zohydro ER: Prescribing information.
5. U.S. Food and Drug Administration. (2024). Hysingla ER: Prescribing information.
6. U.S. Drug Enforcement Administration. (2024). Controlled substance schedules and regulatory requirements.
7. U.S. Food and Drug Administration. (2020). FDA’s development and approval process for abuse-deterrent opioids.