List of Excipients in Branded Drug NORGESIC

« Back to Dashboard

Generic Drugs Containing NORGESIC

Company	Ingredient	NDC	Excipient
Galt Pharmaceuticals LLC	orphenadrine citrate, aspirin and caffeine	61825-305	ANHYDROUS LACTOSE
Galt Pharmaceuticals LLC	orphenadrine citrate, aspirin and caffeine	61825-305	D&C YELLOW NO. 10
Galt Pharmaceuticals LLC	orphenadrine citrate, aspirin and caffeine	61825-305	FD&C BLUE NO. 1

What are the Most Frequently-Used Excipients in NORGESIC?

# Of NDCs	Excipient
1	ANHYDROUS LACTOSE
1	D&C YELLOW NO. 10
1	FD&C BLUE NO. 1

Norgesic Excipient Strategy, Formulation Patents, and Commercial Opportunities

Last updated: October 5, 2026

Norgesic is a legacy fixed-dose combination containing orphenadrine citrate, aspirin, and caffeine. Its commercial opportunity is driven less by active-ingredient exclusivity than by regulatory positioning, tolerability, dose flexibility, and a differentiated oral dosage form. The strongest excipient strategy would target chemical stability, aspirin protection, tablet performance, and a lower-irritation profile without creating unnecessary 505(b)(2) clinical risk.

The traditional Norgesic formulation contains 25 mg orphenadrine citrate, 385 mg aspirin, and 30 mg caffeine per tablet. The product is associated with treatment of painful musculoskeletal conditions involving muscle spasm. Orphenadrine provides the centrally acting muscle-relaxant component; aspirin provides analgesic and anti-inflammatory activity; caffeine may contribute analgesic augmentation and counteract sedation.

Public FDA materials do not indicate a meaningful current Orange Book patent estate for the legacy Norgesic combination. The commercial value therefore depends on a new formulation, a new dosage regimen, an approved regulatory pathway, and enforceable formulation or method-of-use claims.

What is Norgesic and which active ingredients does it contain?

Norgesic is a fixed-dose oral combination of three active ingredients:

Component	Traditional strength per tablet	Functional role
Orphenadrine citrate	25 mg	Centrally acting skeletal-muscle relaxant
Aspirin	385 mg	Analgesic and anti-inflammatory agent
Caffeine	30 mg	Analgesic adjuvant and stimulant

The combination creates formulation constraints. Aspirin is moisture-sensitive and can hydrolyze to salicylic acid and acetic acid. Orphenadrine citrate is a relatively low-dose active ingredient that must be distributed uniformly through a high-load tablet. Caffeine can affect powder flow, dissolution, and tablet hardness.

The product also carries aspirin-related gastrointestinal, bleeding, renal, and hypersensitivity concerns. Orphenadrine has anticholinergic effects, including dry mouth, blurred vision, urinary retention, and potential cognitive or cardiovascular tolerability issues. These safety considerations limit the commercial value of simple line extensions that preserve the same dose and release profile.

What excipients are most important for a Norgesic reformulation?

The most important excipient functions are moisture control, powder-flow improvement, binding, disintegration, lubrication, and taste or gastric tolerability management.

Moisture protection

Aspirin stability should drive the excipient program. Candidate approaches include:

• Low-moisture microcrystalline cellulose.
• Anhydrous dibasic calcium phosphate.
• Pregelatinized starch with controlled water content.
• Colloidal silicon dioxide to reduce powder cohesion.
• Moisture-barrier film coating.
• High-barrier blister packaging using aluminum foil.

Hydrophilic excipients can improve compression but may increase water activity in the tablet. Lactose monohydrate, standard starches, and other water-bearing materials require careful control because aspirin degradation can increase during storage.

A formulation patent is more likely to be defensible if it claims a defined water-activity range, residual-moisture limit, impurity threshold, or stability profile rather than merely listing common excipients.

Direct-compression architecture

A direct-compression tablet may reduce manufacturing steps and improve cost efficiency. A practical platform could use:

• Microcrystalline cellulose as the principal filler and compression aid.
• Anhydrous dibasic calcium phosphate for density and low moisture.
• Crospovidone or croscarmellose sodium for disintegration.
• Colloidal silicon dioxide for flow.
• Magnesium stearate at a controlled concentration for lubrication.

The formulation must prevent segregation between the low-dose orphenadrine component and the larger aspirin load. Ordered mixing, granulation, or separate premixing of orphenadrine with a carrier may be necessary to meet content-uniformity requirements.

Granulation strategy

Wet granulation may improve content uniformity but introduces water and heat, both of which can increase aspirin degradation. If granulation is required, an aqueous process is commercially unattractive unless the product demonstrates strong in-process and long-term stability.

A dry-granulation or roller-compaction process is more compatible with aspirin protection. It may also support a patent position based on compaction force, granule-size distribution, tensile strength, friability, and dissolution performance.

Film coating

A film coat can improve swallowability, reduce aspirin dust, mask taste, and provide a moisture barrier. A suitable system may include a hypromellose or polyvinyl alcohol polymer, plasticizer, pigment, and anti-tacking agent.

A conventional cosmetic film coat is unlikely to create strong patent protection. A stronger claim set would tie the coating to a measurable technical result, such as:

• Reduced salicylic-acid formation.
• Controlled water vapor transmission.
• Improved dissolution after accelerated storage.
• Reduced gastric irritation.
• Preservation of aspirin potency during high-humidity exposure.

What formulation patents could protect a new Norgesic product?

The legacy combination has limited composition-of-matter value because the active ingredients are old and widely known. Patent protection would need to focus on formulation architecture, manufacturing, packaging, or use.

Potential patent claim categories

Claim category	Commercial relevance	Likely strength
Fixed-dose immediate-release tablet	Supports core product	Low to moderate unless technically differentiated
Moisture-stabilized aspirin combination	Addresses principal chemical risk	Moderate if supported by comparative data
Bilayer or multilayer tablet	Separates incompatible ingredients	Moderate to strong if dissolution and stability improve
Modified-release or pulsatile-release dosage form	Creates dosing differentiation	Moderate, but increases regulatory burden
Gastroprotective formulation	Targets aspirin tolerability	Moderate if clinically supported
Orphenadrine dose reduction	Addresses anticholinergic burden	Moderate if linked to therapeutic equivalence or safety
Sachet, orally disintegrating tablet, or liquid	Expands administration options	Low to moderate
Manufacturing process	Can block practical replication	Moderate, but design-around risk is high
Moisture-barrier packaging	Protects shelf life	Low unless integrated with product claims
Method of treating acute musculoskeletal pain	Supports marketing differentiation	Moderate, subject to written-description and clinical evidence

A broad claim covering “orphenadrine, aspirin, caffeine, and a pharmaceutically acceptable excipient” would face substantial prior-art risk. A commercially relevant patent should define the formulation through quantitative ranges, performance limits, or a specific dosage architecture.

How can excipient selection create commercial differentiation?

The highest-value opportunities are products that solve a recognized weakness of the legacy combination.

Low-dose orphenadrine formulation

A lower-orphenadrine product could target patients who experience anticholinergic adverse effects. The formulation might preserve aspirin and caffeine while reducing the muscle-relaxant exposure. This would be a new product rather than a straightforward generic equivalent and could require a 505(b)(2) strategy.

The patent position would depend on evidence that the lower dose maintains efficacy or improves tolerability in a defined patient population.

Gastrointestinal-tolerability platform

Aspirin is the principal commercial liability. Potential approaches include:

• Enteric-coated aspirin particles.
• Delayed-release aspirin with immediate-release orphenadrine and caffeine.
• Polymer-coated aspirin granules.
• Co-packaged gastroprotective therapy.
• Lower aspirin strength with a revised dosing schedule.

Separating aspirin release from orphenadrine release could produce a differentiated product, but it also creates a complex bioavailability and clinical-development program. A delayed-release aspirin formulation may not be therapeutically equivalent to the legacy immediate-release combination.

Bilayer tablet

A bilayer tablet could place orphenadrine and caffeine in one layer and aspirin in another. The benefits include reduced direct contact between ingredients, better segregation control, and the ability to apply different excipient systems to each layer.

The main risks are layer separation, variable hardness, capping, and nonuniform dissolution. A bilayer product is more protectable than a conventional monolithic tablet only when the layer design produces a measurable stability or pharmacokinetic benefit.

Orally disintegrating or smaller tablet

Orally disintegrating tablets could improve administration for patients with swallowing difficulty. The high aspirin dose creates a major taste-masking burden, and caffeine and orphenadrine may contribute to bitterness.

A multiparticulate or mini-tablet platform may be more practical than a conventional orally disintegrating tablet. It could also support flexible dosing, although the resulting product may be more expensive to manufacture and package.

What is the FDA regulatory status and Orange Book position of Norgesic?

Norgesic is a legacy combination rather than a modern, clearly protected reference-product platform. FDA’s Approved Drug Products with Therapeutic Equivalence Evaluations, commonly called the Orange Book, is the principal source for listed patents, exclusivity, and therapeutic-equivalence information. A product absent from the Orange Book does not support a conventional Orange Book patent-certification strategy in the same manner as a listed NDA reference drug. [1]

The key regulatory questions are:

1. Is a current, approved reference listed drug available for the exact combination?
2. Is the proposed product an ANDA candidate or a 505(b)(2) application?
3. Does FDA recognize the same active ingredients, strengths, dosage form, route, and conditions of use?
4. Can the sponsor establish bioequivalence to an approved reference product?
5. Does the reformulation introduce a new release profile or clinical claim?

If an approved reference listed drug is unavailable, a sponsor may need an NDA or 505(b)(2) pathway rather than a conventional ANDA. A 505(b)(2) application can rely partly on FDA findings for previously approved drugs while supporting differences with additional data. [2]

When does Norgesic lose exclusivity and what patent expiration dates apply?

No material current patent-expiration date appears to define market entry for the legacy Norgesic combination. The active ingredients are long-established, and any original product patents would have expired decades ago.

The relevant exclusivity question is therefore not when the legacy product loses exclusivity. It is whether a new sponsor can obtain enforceable protection for:

• A stabilized tablet.
• A bilayer or multilayer dosage form.
• A modified-release profile.
• A defined low-dose regimen.
• A formulation with reduced aspirin degradation.
• A method of treating a specific musculoskeletal condition.

A new formulation patent could provide up to 20 years from the earliest effective nonprovisional filing date, subject to patent-term adjustment and applicable regulatory patent-term extension rules. Product-specific FDA exclusivity would depend on the approval pathway and the nature of the clinical innovation. [3]

Are Paragraph IV challenges likely for a new Norgesic product?

Paragraph IV risk depends on whether the sponsor obtains an Orange Book-listed patent for an approved NDA product. If the product is approved through a 505(b)(2) application and patents are listed, a later ANDA or 505(b)(2) applicant may challenge those patents.

A simple immediate-release tablet would be vulnerable to Paragraph IV attack because:

• The active ingredients are old.
• Common excipients are difficult to monopolize broadly.
• Routine compression and coating methods are often vulnerable to obviousness arguments.
• Design-around options are extensive.

A stronger patent estate would combine multiple layers:

Patent layer	Example protection
Composition	Quantified excipient ranges and low-moisture system
Dosage form	Bilayer, coated granule, or multiparticulate structure
Process	Dry granulation and controlled blending sequence
Stability	Defined impurity and shelf-life thresholds
Method of use	Reduced-dose or defined-patient regimen
Packaging	Barrier package linked to stability performance

The best litigation position would come from patents supported by comparative stability, dissolution, and clinical data, not from ingredient lists alone.

Which companies could challenge or compete with Norgesic?

Competition would likely come from several groups:

• Generic manufacturers of orphenadrine products.
• Suppliers of aspirin and caffeine combination analgesics.
• Manufacturers of skeletal-muscle-relaxant combinations.
• 505(b)(2) developers pursuing improved tolerability.
• Contract manufacturers with high-barrier tablet and multilayer capabilities.
• International companies marketing equivalent orphenadrine combinations.

Potential competitors include manufacturers with established generic portfolios, such as Teva, Viatris, Amneal, Hikma, and Endo-related generic businesses, although competitive participation would depend on the existence of an approved reference product and commercial demand.

The principal substitutes are not limited to exact Norgesic equivalents. They include cyclobenzaprine, methocarbamol, tizanidine, baclofen, NSAID combinations, acetaminophen combinations, and topical analgesic products. These therapies compete for the same musculoskeletal-pain prescriptions.

What licensing and manufacturing opportunities exist?

The most practical licensing opportunities are formulation and manufacturing assets rather than rights to the legacy brand.

Attractive licensing targets

• Low-moisture aspirin granulation technology.
• Bilayer-tablet manufacturing.
• High-barrier blister packaging.
• Orphenadrine content-uniformity processes.
• Taste-masking and multiparticulate systems.
• Stability-indicating analytical methods.
• Regional regulatory dossiers for legacy combination products.

A licensee should value freedom to operate around aspirin combination patents, anticholinergic safety claims, and any third-party modified-release technology. Manufacturing know-how may be more valuable than a narrow formulation patent if it reduces batch failures or extends shelf life.

What generic launch scenarios exist for Norgesic?

Three launch paths are commercially plausible.

Scenario 1: Conventional generic

This is the lowest-cost route if a valid approved reference listed drug exists. The product would seek pharmaceutical equivalence and bioequivalence. Patent and exclusivity barriers appear limited, but reference-product availability is decisive.

Scenario 2: 505(b)(2) reformulation

A sponsor could pursue a moisture-stabilized, lower-dose, bilayer, or modified-release product. This path offers greater differentiation and potential patent protection but requires more formulation, clinical, and regulatory work.

Scenario 3: Non-U.S. regional product

Markets outside the United States may provide opportunities where orphenadrine combinations remain recognized or commercially established. The sponsor would need country-specific evidence on market authorization, controlled-substance treatment, labeling, pharmacovigilance, and local patent status.

How strong is the patent estate for Norgesic?

The legacy patent estate is weak. The active ingredients are old, the combination is conventional, and the principal commercial value lies in product execution.

A new estate could reach moderate strength if it includes:

• Quantitative excipient and moisture limits.
• Comparative stability data.
• A clinically meaningful release profile.
• A defined patient population.
• Multiple manufacturing and packaging claims.
• International filings in high-value markets.

The estate would remain vulnerable if it relies only on common excipients, ordinary film coating, or a generic list of pharmaceutically acceptable carriers.

Key Takeaways

• Norgesic is traditionally a combination of orphenadrine citrate, aspirin, and caffeine.
• Aspirin stability and gastrointestinal tolerability should drive excipient selection.
• A conventional immediate-release tablet has limited patent value.
• Dry granulation, low-moisture excipients, bilayer architecture, and barrier packaging offer stronger technical differentiation.
• The legacy product does not appear to have a material current Orange Book patent barrier.
• Regulatory strategy may require a 505(b)(2) application if an approved reference listed drug is unavailable or the formulation changes materially.
• The strongest commercial opportunity is a differentiated formulation with measurable stability, tolerability, or dosing advantages.
• Generic competition would include both exact-combination products and alternative skeletal-muscle-relaxant therapies.

FAQs

Can lactose be used in a Norgesic tablet?

Lactose can be used from a formulation standpoint, but its water content and compatibility with aspirin require control. Anhydrous or low-moisture fillers may provide a stronger stability profile.

Is an enteric-coated Norgesic product automatically patentable?

No. Enteric coating is a known technique. Patent strength would depend on a specific coating composition, release profile, stability improvement, or clinical benefit supported by data.

Could a Norgesic product be marketed as an over-the-counter drug?

An OTC pathway would require FDA acceptance of the active ingredients, doses, labeling, and combination under an applicable monograph or an approved NDA. The legacy prescription combination should not be assumed to qualify for OTC marketing.

Does caffeine improve the commercial value of Norgesic?

Caffeine may support analgesic positioning and reduce perceived sedation, but it also creates formulation and labeling considerations. Its commercial value depends on demonstrated clinical or consumer benefit.

What is the best excipient for aspirin protection in Norgesic?

No single excipient is sufficient. A low-moisture filler system, controlled granulation process, protective coating, and high-barrier package should be evaluated as an integrated stability program.

References

1. U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations. FDA, Center for Drug Evaluation and Research.

2. U.S. Food and Drug Administration. (2023). Applications covered by section 505(b)(2). FDA, Center for Drug Evaluation and Research.

3. U.S. Patent and Trademark Office. (2024). Patent term adjustment and patent term extension. U.S. Department of Commerce.

4. U.S. Food and Drug Administration. (2024). Inactive ingredient database. FDA, Center for Drug Evaluation and Research.

5. U.S. Pharmacopeial Convention. (2024). United States Pharmacopeia and National Formulary. USP Convention.