List of Excipients in Branded Drug ACAMPROSATE CALCIUM

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Generic Drugs Containing ACAMPROSATE CALCIUM

Company	Ingredient	NDC	Excipient
Teva Pharmaceuticals USA Inc	acamprosate calcium	0093-5352	CELLULOSE, MICROCRYSTALLINE
Teva Pharmaceuticals USA Inc	acamprosate calcium	0093-5352	CROSPOVIDONE
Teva Pharmaceuticals USA Inc	acamprosate calcium	0093-5352	HYPROMELLOSE 2910
Teva Pharmaceuticals USA Inc	acamprosate calcium	0093-5352	MAGNESIUM STEARATE
Teva Pharmaceuticals USA Inc	acamprosate calcium	0093-5352	MAGNESIUM TRISILICATE
Teva Pharmaceuticals USA Inc	acamprosate calcium	0093-5352	METHACRYLIC ACID AND ETHYL ACRYLATE COPOLYMER

What are the Most Frequently-Used Excipients in ACAMPROSATE CALCIUM?

# Of NDCs	Excipient
5	AMMONIA
15	CELLULOSE, MICROCRYSTALLINE
8	CROSPOVIDONE
5	FERROSOFERRIC OXIDE
3	GLYCERYL DIBEHENATE
3	HYPROMELLOSE

Acamprosate Calcium Excipient Strategy, Formulation Patents, and Commercial Opportunities

Last updated: October 16, 2026

Acamprosate calcium is a mature, genericized alcohol-use-disorder medicine sold primarily as a 333 mg delayed-release tablet. The active pharmaceutical ingredient has limited exclusivity value, while commercial opportunities center on adherence, renal-dose flexibility, improved swallowing, lower tablet burden, and manufacturing efficiency. The current reference-product formulation uses an enteric or delayed-release coating supported by conventional tablet excipients. A differentiated product would need to improve usability or economics without compromising acamprosate exposure.

What is the FDA and commercial status of acamprosate calcium?

Acamprosate calcium is FDA-approved under NDA 021431 as Campral delayed-release tablets. The labeled regimen is two 333 mg tablets three times daily for patients with normal renal function, creating a daily tablet burden of six tablets. Patients with moderate renal impairment receive one 333 mg tablet three times daily. Acamprosate is contraindicated in severe renal impairment and is not a controlled substance. It is indicated for maintenance of abstinence from alcohol in patients who are abstinent at treatment initiation. [1]

Attribute	Current position
Active ingredient	Acamprosate calcium
Reference product	Campral
Dosage form	333 mg delayed-release tablet
FDA approval	2004
Therapeutic area	Alcohol-use disorder
Standard dose	666 mg three times daily
Renal-adjusted dose	333 mg three times daily for moderate impairment
Controlled-substance status	Not controlled
Generic pathway	Abbreviated New Drug Application
Biologic status	Not applicable
Primary commercial constraint	High dosing frequency and tablet burden

The US market is no longer protected by meaningful new-drug exclusivity. Generic acamprosate products have established the 333 mg delayed-release tablet as the commercial standard. FDA’s Orange Book remains the controlling source for current reference-product patents, exclusivity, and approved generic competition. [2]

What excipients are used in Campral acamprosate calcium tablets?

The reference product uses a conventional hydrophilic tablet core with a delayed-release coating. The labeled inactive ingredients include crospovidone, microcrystalline cellulose, magnesium silicate, sodium starch glycolate, and colloidal silicon dioxide. The coating includes hypromellose, polyethylene glycol, talc, and titanium dioxide. [1,3]

Excipient	Likely formulation role
Microcrystalline cellulose	Diluent, dry-binding matrix, tablet compressibility
Crospovidone	Superdisintegrant
Sodium starch glycolate	Superdisintegrant and water uptake
Colloidal silicon dioxide	Glidant and flow aid
Magnesium silicate	Processing aid, anti-adherent, mineral filler
Hypromellose	Film-forming coating polymer
Polyethylene glycol	Plasticizer and coating flexibility agent
Talc	Anti-tacking and coating-processing aid
Titanium dioxide	Opacifier and colorant

The formulation challenge is unusual because the product must disintegrate and dissolve rapidly after the delayed-release barrier is removed. Excessive coating strength can delay release or reduce bioavailability. Excessive core disintegration can create manufacturing or stability problems if moisture penetrates the coating.

What excipient strategy is best for generic acamprosate calcium?

The lowest-risk strategy is a close qualitative and quantitative formulation match to the reference product. A generic manufacturer should prioritize:

1. Robust core compression at high production speed.
2. Low moisture exposure during granulation and coating.
3. Consistent delayed-release performance.
4. Minimal tablet weight and size.
5. Stable coating adhesion during packaging and shipping.
6. Compatibility with high-volume, low-cost manufacturing.

Acamprosate calcium is a highly polar, ionic calcium salt. Its formulation is therefore more dependent on aqueous solubility, pH-sensitive release, particle-size distribution, and coating performance than on lipid-based solubilization. Adding surfactants or complex lipid systems would likely add cost without creating a clear clinical advantage.

A direct-compression platform using microcrystalline cellulose, crospovidone, sodium starch glycolate, and colloidal silicon dioxide is commercially attractive when the active ingredient has acceptable flow and compressibility. Roller compaction can be considered when powder flow, segregation, or tablet-weight variation limits direct compression. Wet granulation is less attractive if it increases residual moisture or calcium-salt interaction with excipients.

Which excipients create the highest development risk?

The main risks are associated with:

• Moisture-sensitive delayed-release coatings.
• Excessive tablet swelling before coating rupture.
• Interaction between mineral excipients and coating polymers.
• Inconsistent acamprosate calcium particle size.
• High friability after coating.
• Delayed-release dissolution drift during stability testing.
• Large tablets that worsen adherence.

Magnesium silicate and talc require careful control because mineral excipients can affect powder flow, coating suspension behavior, and dissolution reproducibility. Titanium dioxide is not technically necessary for drug release and can be removed in a clean-label or colorant-free product if the packaging and identification strategy permit it.

What formulation opportunities exist beyond the 333 mg delayed-release tablet?

The strongest commercial opportunities address adherence rather than molecular novelty.

Lower tablet burden

A 666 mg or 999 mg strength could reduce the number of tablets taken per dose. The principal obstacle is tablet size. Acamprosate calcium has a relatively high salt mass, and a high-strength tablet may become difficult to swallow. A multiparticulate capsule, sachet, or oral powder could distribute the dose without creating one very large tablet.

A higher-strength product would require comparative bioavailability, dose-proportionality, dissolution, stability, and human-factors work. It would also need to preserve the delayed-release behavior of the existing product.

Sprinkle or sachet formulation

A delayed-release granule or pellet formulation could be administered by sprinkling onto soft food. This could address patients with dysphagia, older adults, and patients receiving care in structured treatment settings. The dosage form would need protection against crushing, chewing, premature release, and moisture exposure.

A sachet may also reduce unit-dose packaging costs if formulated as a dry, stable multiparticulate product. The commercial opportunity is stronger in institutional and specialty-adherence channels than in broad retail substitution.

Orally disintegrating or rapidly dispersible product

An orally disintegrating tablet could improve administration but creates a technical conflict. Acamprosate calcium should not be released extensively in the mouth or stomach if delayed release is necessary for the intended product profile. A protected microgranule-in-ODT design would be more credible than an uncoated ODT.

The excipient platform could use mannitol, crospovidone, low-substituted hydroxypropyl cellulose, and a moisture-protective barrier. The product would require taste masking, because a rapidly dispersing dosage form exposes the active ingredient to the oral cavity.

Renal-dose packaging

The product already has a lower dose for moderate renal impairment. A commercial package containing 333 mg tablets with renal dosing instructions may improve medication management, but it does not create a new exclusivity position. A 30-day blister pack organized by morning, afternoon, and evening administration could have greater adherence value than a new excipient alone.

Colorant-free and allergen-conscious products

A colorant-free tablet could appeal to institutional buyers and patients seeking simplified excipient profiles. The commercial value is limited unless the product also improves price, supply reliability, or tolerability. Gluten-free, lactose-free, gelatin-free, and vegan positioning may support pharmacy substitution and international tender participation, provided the full excipient and manufacturing chain supports those claims.

What patents protect acamprosate calcium formulations?

The core active-ingredient patent position is weak because acamprosate calcium is an established small-molecule drug with expired US regulatory exclusivity and generic competition. The commercially relevant intellectual-property opportunities are formulation-specific.

IP category	Commercial relevance
Acamprosate calcium compound claims	Low; mature active ingredient
Delayed-release tablet claims	Moderate if they show non-obvious release or stability advantages
Multiparticulate or sprinkle claims	Potentially stronger if supported by clinical or dissolution differentiation
High-strength dosing claims	Potentially relevant but vulnerable to obviousness challenges
Manufacturing-process claims	Useful for cost, yield, and impurity control
Packaging claims	Limited standalone value; stronger when linked to adherence or moisture control
Method-of-use claims	Limited in the US unless tied to a specific, non-obvious patient population or regimen

The original Campral product was approved in 2004, and any original US patent or regulatory exclusivity associated with that launch does not create a current blocking position against ordinary generic 333 mg delayed-release tablets. Current patent conclusions must be based on the live Orange Book record and relevant USPTO prosecution history rather than historical patent listings alone. [2,4]

When does acamprosate calcium lose exclusivity?

Acamprosate calcium has already lost its principal US market exclusivity. The product is accessible through the ANDA pathway, and the competitive market is driven by manufacturing cost, supply continuity, wholesaler contracts, and pharmacy substitution.

Are Paragraph IV challenges relevant?

Paragraph IV litigation is most relevant when a generic applicant certifies that an Orange Book-listed patent is invalid, unenforceable, or not infringed. For a mature acamprosate calcium product, any remaining Paragraph IV issue would likely involve a formulation, method-of-use, or other listed patent rather than the basic active ingredient.

A generic applicant should review:

• Current Orange Book patent listings for NDA 021431.
• Patent expiration and pediatric-extension data.
• Whether any listed patent covers the proposed dosage form.
• The product label’s protected indications and dosing instructions.
• Prior litigation and settlement terms.
• The 30-month-stay risk under the Hatch-Waxman framework.

The standard 333 mg delayed-release tablet has limited apparent exposure to a new blocking patent strategy because generic products are already marketed.

Are biosimilar risks relevant?

No. Acamprosate calcium is a small-molecule drug, not a biologic. Competitive entry occurs through ANDAs and generic substitution, not biosimilar applications under the Public Health Service Act.

What manufacturing and excipient barriers affect market entry?

The main barriers are operational rather than legal. The product requires reliable control of:

• Active particle-size distribution.
• Blend uniformity at relatively high drug loading.
• Tablet tensile strength and friability.
• Coating weight gain.
• Acid-stage resistance.
• Buffer-stage dissolution.
• Residual moisture.
• Packaging protection against humidity.
• Batch-to-batch release consistency.

The delayed-release coating creates the principal manufacturing control point. A supplier with existing enteric-coating capability can enter more quickly than a company that must build new coating capacity. Contract manufacturers with high-throughput film-coating lines, validated dissolution methods, and established stability data have an advantage.

An excipient change may be technically simple but regulatory burdens can be meaningful. A formulation that differs materially from the reference product may require additional comparative dissolution, stability, bioequivalence, or clinical support. FDA’s Inactive Ingredient Database can support excipient selection, but prior use in another product does not eliminate the need to demonstrate suitability in acamprosate calcium. [5]

Which commercial opportunities are most attractive?

Opportunity	Differentiation	Development risk	Commercial outlook
Lower-cost 333 mg delayed-release tablet	Low	Low to moderate	Strongest volume opportunity
666 mg delayed-release tablet	Moderate	Moderate to high	Attractive if tablet size is acceptable
Sprinkle granules	High	High	Niche adherence and institutional opportunity
Moisture-stable blister package	Moderate	Low to moderate	Useful for adherence and supply differentiation
Colorant-free tablet	Low	Low	Limited premium potential
ODT with protected pellets	High	High	Specialty opportunity
Fixed-dose combination	High	Very high	Requires clinical and regulatory justification
New method-of-use product	Variable	High	Patent-dependent and clinically demanding

The best near-term opportunity is a cost-efficient 333 mg delayed-release product with reliable supply and patient-friendly packaging. The best differentiated opportunity is a multiparticulate or sprinkle formulation that reduces swallowing difficulty without compromising delayed release.

How does acamprosate compare with competing alcohol-use-disorder medicines?

Acamprosate competes with oral naltrexone, extended-release injectable naltrexone, disulfiram, and off-label pharmacotherapies. Its principal clinical positioning is maintenance of abstinence after alcohol cessation. Naltrexone has a different pharmacologic profile and may be preferred when reducing heavy drinking is a treatment objective. Disulfiram requires a high level of adherence and behavioral commitment.

Acamprosate’s commercial disadvantage is three-times-daily dosing. Its advantage for formulation developers is that adherence improvement is measurable and commercially understandable. A product that reduces administration frequency, improves swallowing, or supports supervised dosing can compete on use experience even when the active ingredient is generic.

What licensing and partnership opportunities exist?

Licensing value is more likely to arise from formulation technology than from acamprosate calcium itself. Relevant partners include:

• Multiparticulate and pellet-development companies.
• Enteric-coating technology suppliers.
• Contract manufacturers with delayed-release capacity.
• Specialty addiction-treatment platforms.
• Institutional pharmacy distributors.
• Companies with alcohol-use-disorder commercial infrastructure.

A licensee should avoid relying solely on broad excipient claims. Stronger transaction value would come from a protected dosage form supported by human-factors data, improved adherence, manufacturing cost reductions, or a clinically meaningful dosing simplification.

No major current licensing transaction is necessary to commercialize a standard generic tablet. A partnership becomes more relevant for a differentiated delivery system or a market requiring local regulatory and distribution expertise.

What generic launch scenarios exist?

Three launch scenarios are commercially credible:

1. A low-cost AB-rated 333 mg tablet competes through pharmacy substitution and wholesaler pricing.
2. A supply-reliable product wins institutional or public-sector contracts despite limited formulation differentiation.
3. A differentiated multiparticulate or higher-strength product seeks a specialty position based on adherence and administration convenience.

The first scenario has the lowest development risk but the greatest price pressure. The third has higher regulatory and technical risk but offers more defensible commercial positioning.

Key Takeaways

• Acamprosate calcium is a mature, genericized small-molecule medicine with no biosimilar pathway.
• The reference product is a 333 mg delayed-release tablet taken three times daily.
• Core excipients include microcrystalline cellulose, crospovidone, sodium starch glycolate, colloidal silicon dioxide, magnesium silicate, hypromellose, polyethylene glycol, talc, and titanium dioxide.
• The strongest formulation opportunity is adherence improvement through higher strength, multiparticulate, sprinkle, or packaging solutions.
• The strongest generic opportunity is manufacturing efficiency, dissolution consistency, supply reliability, and competitive pricing.
• The active ingredient has limited patent value; formulation, process, and delivery-system claims offer the main potential for new protection.
• Paragraph IV risk is likely to focus on any surviving formulation or method-of-use listing, not the basic active ingredient.
• Revenue potential is volume-driven because the market is generic and the standard product has limited exclusivity protection.

FAQs

Can acamprosate calcium be formulated as a once-daily product?

A once-daily product would require evidence that the new exposure profile preserves efficacy and safety. It would likely need a modified-release system, clinical pharmacology work, and potentially clinical efficacy support.

Which excipient is most important for acamprosate delayed release?

The coating system is more important than any individual tablet-core excipient. Hypromellose, plasticizer concentration, coating weight, and dissolution performance determine whether the product maintains the required delayed-release profile.

Is an acamprosate calcium liquid formulation commercially attractive?

A liquid could address swallowing difficulty, but taste, dose volume, chemical stability, preservative selection, and delayed-release control create substantial development challenges. A protected granule or sprinkle product is more technically aligned with the reference product.

Can a manufacturer remove titanium dioxide from acamprosate tablets?

Yes, a colorant-free product may be technically feasible, but the manufacturer must maintain product identification, appearance consistency, stability, and regulatory comparability.

Does acamprosate calcium have meaningful US patent protection today?

The basic active ingredient and standard delayed-release tablet are not protected by the original launch exclusivity. Any current blocking position would depend on live Orange Book listings and enforceable formulation, process, or method-of-use patents.

References

1. U.S. Food and Drug Administration. (2004). Campral (acamprosate calcium) delayed-release tablets: Prescribing information.
2. U.S. Food and Drug Administration. (n.d.). Approved drug products with therapeutic equivalence evaluations: Orange Book.
3. DailyMed. (n.d.). Campral- acamprosate calcium tablet, delayed release. U.S. National Library of Medicine.
4. U.S. Patent and Trademark Office. (n.d.). Patent Center and Patent Examination Data System.
5. U.S. Food and Drug Administration. (n.d.). Inactive Ingredient Database.