List of Excipients in Branded Drug ACETAMINOPHEN, CAFFEINE AND DIHYDROCODEINE BITARTRATE

« Back to Dashboard

Generic Drugs Containing ACETAMINOPHEN, CAFFEINE AND DIHYDROCODEINE BITARTRATE

Company	Ingredient	NDC	Excipient
Larken Laboratories Inc	acetaminophen, caffeine and dihydrocodeine bitartrate	68047-720	CELLULOSE, MICROCRYSTALLINE
Larken Laboratories Inc	acetaminophen, caffeine and dihydrocodeine bitartrate	68047-720	CROSPOVIDONE
Larken Laboratories Inc	acetaminophen, caffeine and dihydrocodeine bitartrate	68047-720	MAGNESIUM STEARATE
Larken Laboratories Inc	acetaminophen, caffeine and dihydrocodeine bitartrate	68047-720	POVIDONE K30
Larken Laboratories Inc	acetaminophen, caffeine and dihydrocodeine bitartrate	68047-720	SILICON DIOXIDE

What are the Most Frequently-Used Excipients in ACETAMINOPHEN, CAFFEINE AND DIHYDROCODEINE BITARTRATE?

# Of NDCs	Excipient
2	CELLULOSE, MICROCRYSTALLINE
2	CROSPOVIDONE
2	MAGNESIUM STEARATE
2	POVIDONE K30
2	SILICON DIOXIDE

Acetaminophen, Caffeine and Dihydrocodeine Bitartrate: Excipient Strategy and Commercial Opportunities

Last updated: September 1, 2026

The combination of acetaminophen, caffeine, and dihydrocodeine bitartrate is a mature prescription analgesic platform with limited active-ingredient patent value and greater opportunity in formulation, supply reliability, manufacturing efficiency, and differentiated delivery. The U.S. reference product is Trezix, an oral capsule containing acetaminophen 320 mg, caffeine 50 mg, and dihydrocodeine bitartrate 16 mg per dosage unit.[1]

The strongest commercial opportunities are generic or authorized-generic entry, supply-chain improvements, capsule and tablet cost reduction, controlled-release development, and formulation strategies that improve dose uniformity, stability, swallowability, or abuse-risk controls. Conventional excipient substitutions alone are unlikely to create substantial market exclusivity.

What drug product contains acetaminophen, caffeine, and dihydrocodeine bitartrate?

The best-known U.S. product is Trezix, marketed as a prescription oral analgesic for acute pain severe enough to require an opioid when alternative treatments are inadequate.[1]

Attribute	Public product information
Reference product	Trezix
Active ingredients	Acetaminophen, caffeine, dihydrocodeine bitartrate
Strength per capsule	Acetaminophen 320 mg; caffeine 50 mg; dihydrocodeine bitartrate 16 mg
Dosage form	Oral capsule
U.S. regulatory pathway	505(b)(2) or NDA-based reference product; generic copies would generally use the ANDA pathway
Controlled-substance status	Dihydrocodeine-containing products are subject to U.S. controlled-substance requirements; scheduling depends on formulation and strength
Primary therapeutic use	Acute pain
Key safety constraints	Opioid respiratory depression, dependence, misuse, acetaminophen hepatotoxicity, caffeine-related effects

The formulation combines a nonopioid analgesic, a methylxanthine commonly used as an analgesic adjuvant, and an opioid agonist. The combination creates a multidimensional formulation problem: the product must maintain content uniformity across three actives while controlling opioid handling, acetaminophen exposure, capsule performance, and manufacturing segregation.

What excipients are commercially relevant for this combination?

The core excipient strategy should prioritize content uniformity, powder flow, capsule filling, moisture control, dissolution, and low-cost scale-up.

Functional excipient categories

Formulation need	Relevant excipient classes	Commercial objective
Powder flow	Colloidal silicon dioxide, glidants	Improve capsule-fill consistency
Binding and granulation	Povidone, hydroxypropyl cellulose, pregelatinized starch	Reduce segregation and improve granule strength
Disintegration	Crospovidone, croscarmellose sodium, sodium starch glycolate	Maintain rapid release
Dilution	Microcrystalline cellulose, lactose, mannitol, dibasic calcium phosphate	Adjust fill weight and improve manufacturability
Lubrication	Magnesium stearate, sodium stearyl fumarate	Reduce ejection force while limiting dissolution impact
Wetting	Sodium lauryl sulfate or other surfactants	Improve wetting of poorly dispersing components
Taste and odor control	Film coatings, capsule-shell systems, ion-exchange approaches	Improve patient acceptability and reduce tampering
Moisture protection	Low-moisture excipients, high-barrier blister packaging, desiccants	Protect stability and capsule performance
Color and identification	Approved capsule colorants and imprint systems	Reduce medication errors and support product differentiation

The three active ingredients have different physical and chemical profiles. Acetaminophen is relatively high dose compared with caffeine and dihydrocodeine bitartrate. The lower-dose actives create segregation and sampling risks during blending. Caffeine can migrate or segregate depending on particle-size distribution and density. Dihydrocodeine bitartrate is present at a substantially lower mass than acetaminophen, increasing the importance of ordered blending, geometric dilution, granulation, or validated low-dose premixes.

Excipient selection priorities

A direct-blend capsule may offer the lowest cost, but it requires tight control of particle size, bulk density, electrostatic behavior, and blend uniformity. A wet- or dry-granulated approach can reduce segregation, but it increases process complexity and may affect dissolution or stability.

A practical development sequence is:

1. Characterize particle size, morphology, density, flow, and hygroscopicity for each active.
2. Screen direct blending with microcrystalline cellulose or lactose-based diluents.
3. Use geometric dilution or a carrier-based premix for dihydrocodeine bitartrate.
4. Evaluate dry granulation if blend segregation persists.
5. Use a low-level surfactant only where dissolution or wetting data support it.
6. Confirm that lubricant concentration and blending time do not delay release.
7. Establish impurity and degradation profiles under accelerated and long-term conditions.

The main quality risk is not simply dissolution. It is uniform delivery of dihydrocodeine and caffeine across individual capsules, batches, and production equipment.

What formulation patents could protect this product?

The active ingredients are old, and basic use of acetaminophen, caffeine, and dihydrocodeine bitartrate is unlikely to support meaningful new composition-of-matter protection. Commercially relevant patent opportunities would instead arise from a non-obvious formulation or manufacturing improvement.

Potential claim areas include:

• Controlled-release or abuse-deterrent delivery.
• A multiparticulate formulation with separated or staged release of the three actives.
• A low-segregation granulation process that improves dihydrocodeine content uniformity.
• A moisture-resistant capsule or tablet platform.
• A taste-masked oral dosage form.
• A fast-disintegrating tablet with validated opioid content uniformity.
• A fixed-dose product with reduced acetaminophen exposure.
• A formulation that reduces caffeine-related adverse effects through modified release.
• A tamper-resistant matrix or polymer system.
• A manufacturing process that reduces residual opioid contamination and cleaning burden.

A patent directed only to replacing lactose with microcrystalline cellulose, or magnesium stearate with another conventional lubricant, would generally face a weak inventive-step position unless the change produces an unexpected technical effect.

What is the Orange Book status and exclusivity timeline?

The relevant reference product is Trezix under NDA 021692. The FDA Orange Book should be used for current listed patents, therapeutic-equivalence codes, and marketing status.[2]

Exclusivity or protection category	Assessment
New chemical entity exclusivity	Not available for these long-established active ingredients
Five-year NCE exclusivity	Not applicable
Three-year clinical-investigation exclusivity	Any original period would have expired
Pediatric exclusivity	No current protection expected from the mature product
Basic active-ingredient patents	Expired or unavailable
Formulation patents	Must be confirmed against the current Orange Book listing
Generic pathway	ANDA, subject to reference-product status and applicable bioequivalence requirements

The product’s practical exclusivity position is therefore driven by regulatory status, manufacturing capability, controlled-substance compliance, supply contracts, and commercial execution rather than by an extended patent term.

When does this product lose exclusivity?

For a mature fixed-dose combination of established active ingredients, the meaningful exclusivity window generally has already expired. Generic entrants can pursue an ANDA if they can demonstrate pharmaceutical equivalence and bioequivalence to the reference product and satisfy FDA requirements for controlled-substance products.[3]

The commercial launch date for a generic depends on:

• FDA approval of the ANDA.
• Any applicable Paragraph IV certification and litigation stay.
• Controlled-substance registration and quota availability.
• DEA manufacturing and distribution requirements.
• Active pharmaceutical ingredient sourcing.
• State opioid prescribing and dispensing restrictions.
• Commercial access to wholesalers, pharmacies, and payers.

A generic applicant does not need to reproduce every inactive ingredient. FDA permits differences in excipients if the product remains pharmaceutically equivalent, meets quality requirements, and demonstrates bioequivalence. The applicant must assess whether excipient differences affect dissolution, absorption, tolerability, or safety.

Are Paragraph IV challenges likely for this drug?

Paragraph IV risk appears limited if the Orange Book contains no blocking, unexpired patent claims covering the reference product. A Paragraph IV certification would become relevant only if an unexpired listed patent covered the product, an approved use, or a formulation required for the proposed generic.

For this combination, the more likely regulatory route is a Paragraph III or “no patent certification” approach, depending on the current Orange Book record. The commercial value of a Paragraph IV strategy would be low unless the reference product has an active listed formulation or method-of-use patent.

Non-Orange Book patents could still affect a differentiated product. They would matter most for:

• Controlled-release delivery.
• Abuse-deterrent technology.
• Specialty capsule shells.
• Novel manufacturing processes.
• Device-enabled administration.
• Taste-masking systems.

Those patents may create litigation exposure but would not necessarily block an ordinary immediate-release ANDA.

What excipient strategies offer the strongest commercial opportunity?

Low-cost generic capsule

The lowest-risk opportunity is a conventional immediate-release capsule using widely available excipients. The commercial thesis is manufacturing efficiency rather than product differentiation.

Key advantages include:

• Short development cycle.
• Established dosage form.
• Broad excipient supply base.
• Limited clinical development requirements.
• Potential use of a standard capsule-filling platform.

The principal risks are opioid API sourcing, DEA quota, blend uniformity, and price erosion after multiple generic approvals.

Tablet conversion

A tablet could reduce capsule-shell costs, improve packaging efficiency, and simplify automated production. A film-coated tablet could also provide branding flexibility and tamper-evident characteristics.

The development burden is higher because compression behavior, segregation during tableting, hardness, friability, disintegration, and dissolution must be controlled. A tablet may also require a larger formulation mass or a multilayer architecture to separate incompatible release profiles.

Extended-release formulation

An extended-release product could support a premium product position, but it would likely require substantial pharmacokinetic and clinical development. The combination raises a safety concern: modified release of dihydrocodeine can increase the consequences of dose dumping or accidental overexposure.

Potential designs include:

• Hydrophilic polymer matrices.
• Multiparticulate pellets.
• Separate immediate-release and extended-release populations.
• Osmotic or coated-particle systems.
• Differential release of caffeine and dihydrocodeine.

This route has greater patent potential than a standard capsule but also the highest regulatory, abuse-liability, and clinical risk.

Abuse-deterrent formulation

An abuse-deterrent product may qualify for differentiated labeling only if it meets FDA expectations for abuse-deterrent technology and supporting evidence.[4] Conventional capsule excipients do not provide abuse deterrence. Technologies must address one or more manipulation routes, such as crushing, chewing, extraction, or dissolution.

The opportunity is strategically attractive but difficult to validate. The product contains relatively modest opioid content per capsule, which may reduce the commercial return on expensive abuse-deterrence development.

Patient-acceptability formulation

Taste masking, reduced capsule size, easier swallowing, and lower moisture sensitivity could improve adherence and pharmacy preference. These features may support a defensible formulation patent if linked to measurable performance advantages.

What manufacturing and intellectual-property barriers affect market entry?

The principal barriers are operational.

Controlled-substance supply

Dihydrocodeine is subject to controlled-substance controls in the United States. A manufacturer must manage DEA registration, procurement, storage, recordkeeping, security, quota, and diversion controls.[5] These requirements narrow the field of potential suppliers and can cause shortages even when the dosage form is technically simple.

Low-dose uniformity

Dihydrocodeine bitartrate is a low-dose component relative to acetaminophen. The manufacturer must control:

• Premix concentration.
• Blend segregation.
• Sampling plans.
• Equipment hold-up.
• Line clearance.
• Cleaning validation.
• Cross-contamination risk.

A process patent based on improved low-dose uniformity could have commercial value if it demonstrates reproducible performance at scale.

Acetaminophen exposure

The labeling must address total acetaminophen exposure from all prescription and nonprescription sources. FDA has taken steps to reduce acetaminophen-related liver injury and has limited the acetaminophen content of prescription combination products.[6] A formulation that increases dose frequency or facilitates accidental accumulation would create regulatory and commercial disadvantages.

API quality and impurity control

Acetaminophen degradation, caffeine variability, and opioid-related impurities require a coordinated control strategy. Suppliers should be qualified for compendial compliance, residual solvents, elemental impurities, nitrosamines where relevant, and change-control discipline.

How does this product compare with acetaminophen-codeine and tramadol combinations?

Product class	Commercial strength	Main formulation issue	Competitive risk
Acetaminophen/caffeine/dihydrocodeine	Strong analgesic positioning with stimulant adjuvant	Low-dose opioid uniformity and controlled-substance handling	Generic price erosion; opioid prescribing limits
Acetaminophen/codeine	Broad historical familiarity	Acetaminophen exposure and codeine metabolic variability	Larger generic field
Tramadol/acetaminophen	Nontraditional opioid positioning	Modified-release and dose-related adverse effects	Alternative prescribing preferences
NSAID/opioid combinations	Potential opioid-sparing effect	Gastrointestinal, renal, or bleeding risks	May be preferred for inflammatory pain
Nonopioid combinations	Lower controlled-substance burden	May provide less analgesic intensity	Increasing payer and prescriber preference

The caffeine-containing combination may differentiate itself through perceived analgesic enhancement, but the benefit must be commercially meaningful to offset controlled-substance restrictions and opioid stewardship policies.

What licensing deals and partnership models are available?

The most practical transactions involve manufacturing and distribution rather than discovery licensing.

Potential structures include:

• API supply and dual-source agreements for dihydrocodeine bitartrate.
• Contract development and manufacturing organization partnerships.
• Authorized-generic arrangements with the NDA holder.
• Regional commercialization licenses.
• Co-development of an abuse-deterrent or extended-release version.
• Acquisition of a validated capsule or tablet platform.
• Supply agreements tied to DEA quota allocation.
• Private-label distribution through specialty pharmacies.

A buyer should value this product on net sales durability, supply reliability, payer access, and opioid-policy exposure. Patent term should receive limited valuation weight unless a separate differentiated formulation has enforceable claims.

What generic launch scenarios exist?

Standard ANDA launch

This is the most probable scenario. The entrant uses an immediate-release capsule, demonstrates bioequivalence, and competes primarily on price and supply reliability.

Limited-competition launch

A manufacturer with an approved product may obtain attractive margins if few suppliers maintain controlled-substance capabilities or if API shortages limit competition.

Multi-entrant price erosion

Once several ANDAs are approved, the product may experience rapid price compression. The first approved generic can retain a temporary commercial advantage through wholesaler contracts and pharmacy substitution, but that advantage is usually short-lived.

Differentiated formulation launch

A new tablet, controlled-release product, or abuse-deterrent formulation could avoid direct commodity competition. It would require greater development spending and may need a new NDA or 505(b)(2) application rather than a conventional ANDA.

Key Takeaways

• Trezix is the principal U.S. reference product for this combination, containing acetaminophen 320 mg, caffeine 50 mg, and dihydrocodeine bitartrate 16 mg per capsule.[1]
• The active ingredients are mature, so basic composition-of-matter exclusivity is not a commercial driver.
• Conventional excipient substitutions are useful for cost, flow, uniformity, and stability but usually provide weak patent protection.
• The highest-value technical opportunity is improving low-dose dihydrocodeine uniformity while preserving immediate release.
• Extended-release and abuse-deterrent products offer greater patent potential but require materially higher regulatory and clinical investment.
• Generic entry depends more on ANDA approval, DEA controls, API supply, and opioid-market access than on basic formulation patents.
• Commercial diligence should focus on Orange Book listings, current marketing status, controlled-substance supply, net pricing, and the number of active generic competitors.

Frequently Asked Questions

Can lactose be replaced in an acetaminophen-caffeine-dihydrocodeine capsule?

Yes. Lactose can potentially be replaced with microcrystalline cellulose, mannitol, dibasic calcium phosphate, or another suitable diluent, subject to compatibility, content uniformity, dissolution, stability, and bioequivalence requirements.

Is a new excipient combination likely to receive a patent?

Usually not by itself. Patentability is stronger when the excipient system produces an unexpected result, such as materially improved opioid uniformity, reduced degradation, faster disintegration, or demonstrated tamper resistance.

Does caffeine create a separate patent opportunity?

Caffeine alone is not patentable as a new chemical entity in this context. A staged-release system or a formulation that changes caffeine exposure could provide a basis for patent claims if the technical effect is novel and non-obvious.

Can this product be developed as an orally disintegrating tablet?

Potentially, but the dosage form must manage the bitter taste of the actives, tablet friability, opioid content uniformity, moisture sensitivity, and rapid release. Taste masking and abuse-risk controls would be central development issues.

What is the largest commercial risk for a generic manufacturer?

The largest risks are controlled-substance API availability, DEA quota constraints, opioid-related market restrictions, rapid generic price erosion, and insufficient scale to support compliant manufacturing and distribution.

References

1. U.S. Food and Drug Administration. (2023). Trezix: Prescribing information.
2. U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations: Orange Book.
3. U.S. Food and Drug Administration. (2023). Guidance for industry: ANDAs for certain highly purified synthetic peptides.
4. U.S. Food and Drug Administration. (2015). Abuse-deterrent opioids: Evaluation and labeling guidance for industry.
5. Drug Enforcement Administration. (2024). Controlled substances laws and regulations.
6. U.S. Food and Drug Administration. (2011). Questions and answers about FDA’s actions regarding prescription combination products containing more than 325 mg of acetaminophen.