List of Excipients in Branded Drug CONTRAVE

« Back to Dashboard

Company	Tradename	Ingredient	NDC	Excipient	Potential Generic Entry
PD-Rx Pharmaceuticals Inc	CONTRAVE	naltrexone hydrochloride and bupropion hydrochloride	43063-772	ANHYDROUS LACTOSE	2027-06-04
PD-Rx Pharmaceuticals Inc	CONTRAVE	naltrexone hydrochloride and bupropion hydrochloride	43063-772	CELLULOSE, MICROCRYSTALLINE	2027-06-04
PD-Rx Pharmaceuticals Inc	CONTRAVE	naltrexone hydrochloride and bupropion hydrochloride	43063-772	CROSPOVIDONE	2027-06-04
PD-Rx Pharmaceuticals Inc	CONTRAVE	naltrexone hydrochloride and bupropion hydrochloride	43063-772	CYSTEINE HYDROCHLORIDE	2027-06-04
PD-Rx Pharmaceuticals Inc	CONTRAVE	naltrexone hydrochloride and bupropion hydrochloride	43063-772	EDETATE DISODIUM	2027-06-04
PD-Rx Pharmaceuticals Inc	CONTRAVE	naltrexone hydrochloride and bupropion hydrochloride	43063-772	FD&C BLUE NO. 2	2027-06-04

Contrave Excipient Strategy and Commercial Opportunities in Extended-Release Obesity Treatment

Last updated: October 19, 2026

Contrave combines naltrexone hydrochloride and bupropion hydrochloride in a fixed-dose, extended-release tablet. Its excipient strategy must control release from two pharmacologically different active ingredients, maintain tablet integrity during dose escalation, and prevent dose dumping when tablets are crushed or chewed. The commercial opportunity is strongest in direct-compression excipients, controlled-release polymers, coating systems, analytical services, and differentiated generic or lifecycle formulations.

What is Contrave and how is its tablet formulated?

Contrave is an oral prescription medicine approved by the U.S. Food and Drug Administration for chronic weight management in adults with obesity or overweight with at least one weight-related comorbidity. It contains 8 mg of naltrexone hydrochloride and 90 mg of bupropion hydrochloride per tablet in an extended-release dosage form. The approved escalation schedule reaches two tablets twice daily, for a total daily dose of 32 mg naltrexone hydrochloride and 360 mg bupropion hydrochloride. [1]

Attribute	Contrave specification
Active ingredients	Naltrexone hydrochloride and bupropion hydrochloride
Strength per tablet	8 mg/90 mg
Maximum daily dose	32 mg/360 mg
Dosage form	Extended-release, film-coated tablet
Administration	Oral; tablets must be swallowed whole
Initial titration	Four-week dose escalation
U.S. NDA	200063
Original FDA approval	2014
Current U.S. commercial rights	Currax Pharmaceuticals
Therapeutic area	Chronic weight management

The FDA-approved inactive ingredients include lactose anhydrous, microcrystalline cellulose, hypromellose, croscarmellose sodium, colloidal silicon dioxide, magnesium stearate, povidone, disodium edetate and coloring agents. The tablet is film-coated. [1]

The formulation has a high excipient-to-active ratio because each tablet contains 98 mg of active pharmaceutical ingredients before accounting for salts, processing aids, release-control polymers, coating materials and other excipients.

What excipient functions are required in Contrave?

Contrave requires more than conventional tablet binding and lubrication. The formulation must provide extended release for both actives while preserving a reproducible dissolution profile across four daily dose levels.

Release-control matrix

Hypromellose is the principal strategic excipient class because it hydrates after ingestion and forms a gel layer that controls diffusion and erosion. Polymer grade, viscosity, particle size and substitution pattern can materially affect release.

A generic developer cannot assume that any hypromellose grade will reproduce the reference product. Changes in polymer viscosity, compression force, tablet porosity or granulation moisture can shift the release profile for both naltrexone and bupropion.

Binder and compressibility system

Microcrystalline cellulose and povidone support powder flow, granule strength and tablet tensile strength. The selected grades must tolerate a relatively large tablet burden while maintaining low friability and consistent weight.

Direct compression is commercially attractive because it reduces processing steps. Wet granulation may offer better content uniformity and flow, but it introduces moisture and drying variables that can change polymer hydration and dissolution.

Disintegrant balance

Croscarmellose sodium supports tablet breakup and hydration. In an extended-release matrix, excessive disintegrant can accelerate drug release and undermine the controlled-release mechanism. Insufficient disintegration can create incomplete or delayed release.

The disintegrant level must be optimized against the hypromellose matrix rather than maximized for rapid tablet breakup.

Lubrication and surface properties

Magnesium stearate improves ejection but can create hydrophobic coating on particles when overmixed. That effect can alter wetting, tablet hardness and dissolution. Lubricant concentration and blending time are therefore critical process variables.

Colloidal silicon dioxide improves flow and reduces segregation risk. Its level can affect powder rheology and blend uniformity, particularly when the two active ingredients have different particle-size distributions or bulk densities.

Chelation and stability control

Disodium edetate is included in the FDA-listed formulation. Chelating agents can reduce metal-catalyzed degradation pathways, although the commercial value depends on impurity profiles, packaging conditions and long-term stability data.

Film coating provides color, swallowability and protection from handling damage. It must not materially alter moisture uptake or release performance.

What technical barriers affect generic Contrave development?

The key barrier is simultaneous control of two active ingredients with different physicochemical properties.

Bupropion hydrochloride is highly water soluble, while naltrexone hydrochloride has different solubility and dose characteristics. A single matrix therefore must avoid rapid bupropion release while maintaining adequate naltrexone release. The developer must match the reference product across multiple dissolution media and sampling intervals.

The label prohibits crushing, chewing or splitting Contrave tablets because these actions can alter extended release. [1] That requirement creates a manufacturing and quality-control target: the intact tablet must release the actives predictably, while mechanical damage must not create an unsafe dose-dumping profile.

Important development variables include:

• Hypromellose viscosity and loading
• Active particle size and morphology
• Granulation route
• Compression force and tablet porosity
• Lubrication time
• Coating weight gain
• Water activity and residual moisture
• Packaging moisture barrier
• Dissolution method and acceptance criteria
• Stability of both active ingredients in the matrix

A formulation that matches assay and weight but fails dissolution similarity is unlikely to support a reliable abbreviated new drug application.

What formulations are protected by Contrave patents?

Contrave’s patent estate has focused on combinations of naltrexone and bupropion, controlled-release dosage forms and methods of treating obesity. The relevant U.S. patents have been associated with Orexigen Therapeutics and its successors, with commercial rights later held by Currax Pharmaceuticals.

Public FDA Orange Book records should be used for the current patent listing, expiration and certification status. The principal patent families historically associated with Contrave include:

Patent family	General subject matter	Commercial relevance
U.S. Patent No. 8,916,195	Naltrexone/bupropion pharmaceutical compositions	Combination-product and formulation barrier
U.S. Patent No. 9,526,734	Naltrexone/bupropion treatment methods	Method-of-use exposure
Related continuation families	Controlled-release combinations and obesity treatment	Potentially relevant to ANDA certifications

Patent term can differ from the nominal 20-year term because of patent-term adjustment, patent-term extension, terminal disclaimers and regulatory listing practices. A commercial launch analysis must rely on the current Orange Book entry and litigation record rather than a single expiration date. [2]

When does Contrave lose exclusivity?

Contrave’s principal commercial protection consists of patents rather than a durable biologic-style exclusivity period. The NDA was approved in 2014, and the product’s five-year new-chemical-entity exclusivity period has expired. The remaining barrier is therefore patent scope and enforceability, together with the cost of developing a bioequivalent extended-release product. [1,2]

A generic applicant seeking approval before listed patent expiry may submit a Paragraph IV certification alleging that a listed patent is invalid, unenforceable or not infringed. The certification can trigger patent litigation and a potential 30-month stay of FDA approval under the Hatch-Waxman framework. [3]

The practical launch date depends on:

1. The patents listed for NDA 200063 at the time of ANDA filing.
2. The generic applicant’s Paragraph IV position.
3. Whether the NDA holder files a timely infringement action.
4. The outcome of the litigation or settlement.
5. Any pediatric exclusivity or other regulatory period attached to the listed patents.

What is the Orange Book status of Contrave?

Contrave is an FDA-approved small-molecule combination product listed in the Orange Book under NDA 200063. Its Orange Book status is commercially important because the listed patents define the principal Hatch-Waxman challenge pathway. [2]

The Orange Book does not establish that a patent is valid or enforceable. It identifies patents submitted by the NDA holder that the FDA has listed against the approved product. Patent disputes are resolved in federal court, not by the FDA.

A generic company must evaluate both formulation patents and method-of-use patents. A skinny-label strategy may address method claims by omitting protected indications or dosing instructions, but it does not eliminate exposure to formulation claims covering the tablet itself.

Which companies are challenging Contrave exclusivity?

Contrave has been marketed by Currax Pharmaceuticals, which acquired the product and related rights from Orexigen’s bankruptcy estate. Publicly available regulatory and patent sources should be reviewed for current ANDA applicants, Paragraph IV notices and litigation developments. [4]

The competitive field includes:

• Generic pharmaceutical companies developing naltrexone/bupropion extended-release tablets.
• Contract development and manufacturing organizations with matrix-tablet expertise.
• Excipient suppliers offering high-viscosity hypromellose and direct-compression systems.
• Obesity-drug manufacturers competing with GLP-1 receptor agonists and other weight-management therapies.

No biosimilar pathway applies. Contrave is a chemically synthesized small-molecule product, so competitive entry would proceed through an ANDA or, in some circumstances, a 505(b)(2) application rather than a biosimilar application.

How strong is the Contrave patent estate?

The estate is stronger against simple formulation copying than against all alternative dosage-form approaches. Combination-product claims can create meaningful risk for a generic tablet that uses the same active ingredients and broadly similar extended-release architecture.

Its strength depends on claim construction, prosecution history, written-description support, prior art and the precise formulation used by the challenger. Method-of-use claims may be narrower because obesity treatment overlaps with a substantial prior-art field involving naltrexone, bupropion and weight management.

The highest-risk generic design is a fixed-dose extended-release tablet that reproduces the reference product’s composition and release mechanism. Lower-risk approaches may include materially different matrix systems, distinct release-control technologies or dosage forms that can support a 505(b)(2) pathway. Those alternatives face their own bioequivalence, clinical, manufacturing and patent risks.

What commercial opportunities exist for excipient suppliers?

The most attractive excipient opportunities are tied to formulation performance rather than simple ingredient substitution.

High-viscosity hypromellose

Suppliers can compete on controlled-release grades, lot-to-lot consistency, particle engineering and regulatory support. A supplier able to demonstrate robust release across compression and scale-up conditions can become embedded in a generic development program.

Co-processed direct-compression excipients

Co-processed cellulose, silicified microcrystalline cellulose and multifunctional filler-binder systems can reduce segregation and improve tablet tensile strength. The commercial value is higher when the platform supports continuous manufacturing or high-speed tableting.

Functional coating systems

Film-coating suppliers can offer low-moisture, low-weight-gain systems with improved color uniformity and mechanical protection. Coatings that minimize impact on dissolution are particularly relevant to extended-release tablets.

Taste and swallowability technologies

Contrave tablets must be swallowed whole, but coating quality still affects patient acceptability. Smooth, low-friction coatings and reduced tablet bulk can support adherence during the four-week dose escalation period.

Analytical and development services

Specialized laboratories can provide comparative dissolution, powder rheology, solid-state characterization, extractables and leachables testing, and stability modeling. These services are commercially valuable because the product’s risk is concentrated in release behavior and process reproducibility.

How does Contrave compare with competing obesity drugs?

Contrave competes with injectable and oral obesity treatments, including GLP-1 receptor agonists and other chronic weight-management products. Its principal commercial advantages are oral administration and a non-peptide mechanism. Its disadvantages include dose escalation, opioid-related contraindication issues, neuropsychiatric warnings and generally lower market momentum than leading incretin therapies. [1,5]

Product category	Dosage form	Excipient opportunity	Generic or biosimilar risk
Contrave	Extended-release tablet	Matrix polymers, compression systems, coatings	Generic ANDA
GLP-1 receptor agonists	Injectable or oral peptide products	Stabilizers, device materials, protein-compatible buffers	Biosimilar or follow-on risk, depending on product
Orlistat	Capsule	Lipid-compatible excipients and capsule systems	Generic
Phentermine/topiramate	Extended-release capsule	Multiparticulate release systems	Generic ANDA

Contrave’s excipient strategy is more accessible to conventional generic manufacturers than peptide injection technology, but its dual-active dissolution profile creates a more demanding oral solid-dose development program.

What generic launch scenarios exist for Contrave?

Three launch scenarios are commercially relevant.

At-risk launch

A generic company launches after receiving FDA approval but before final resolution of patent litigation. This creates potential damages exposure and an injunction risk. The upside is early market entry; the downside is substantial legal liability.

First-filer launch

A Paragraph IV applicant may obtain 180-day generic exclusivity if statutory conditions are met. The commercial value depends on whether other applicants share eligibility and whether litigation or forfeiture provisions affect the exclusivity period. [3]

Post-patent launch

Multiple manufacturers enter after patent barriers expire or are invalidated. Price erosion is likely to be faster because the product uses conventional oral-solid-dose manufacturing and does not require biologic comparability studies.

What manufacturing and geographic IP barriers exist?

The manufacturing barrier is moderate. The active ingredients and common excipients are available from multiple suppliers, and the product does not require sterile production or cold-chain distribution.

The principal manufacturing risks are:

• Maintaining blend uniformity for two actives
• Reproducing extended-release dissolution
• Controlling tablet hardness without slowing release excessively
• Managing moisture during granulation and storage
• Demonstrating stability in commercial packaging
• Meeting scale-up specifications across manufacturing sites

U.S. patent exposure is central to an ANDA strategy, but international protection varies by country. A company can face different launch dates in the United States, Europe, Canada and other markets because patent filings, supplementary protection certificates, national litigation and regulatory exclusivity do not align automatically.

Key Takeaways

• Contrave is an extended-release 8 mg/90 mg naltrexone/bupropion tablet approved under NDA 200063.
• Its core excipient challenge is simultaneous release control for two active ingredients with different physicochemical properties.
• Hypromellose, microcrystalline cellulose, povidone, croscarmellose sodium, magnesium stearate and coating materials are commercially relevant formulation variables.
• Generic development risk is concentrated in dissolution similarity, tablet robustness and patent claims covering the fixed-dose extended-release combination.
• Contrave has no biosimilar pathway because it is a small-molecule product.
• Excipient suppliers have the strongest opportunities in high-viscosity polymers, co-processed direct-compression systems, functional coatings and comparative analytical services.
• Patent and Paragraph IV analysis must use the current Orange Book listing and litigation record for NDA 200063.
• The most credible generic launch pathway is an ANDA supported by a formulation that achieves reference-product dissolution without unnecessarily replicating every excipient or process feature.

FAQs

Can a generic Contrave tablet use different excipients?

Yes. An ANDA generally does not require an identical inactive-ingredient composition, but the proposed product must satisfy pharmaceutical equivalence, bioequivalence, quality and labeling requirements. Different excipients can create dissolution or tolerability issues.

Is hypromellose essential to Contrave generic development?

Hypromellose is not necessarily legally mandatory, but a comparable hydrophilic matrix polymer is likely required to reproduce extended release. A different polymer system would need strong comparative dissolution and bioequivalence support.

Does Contrave require a biosimilar application?

No. Contrave contains small-molecule active ingredients. A competing product would generally use the ANDA pathway, or potentially a 505(b)(2) pathway for a materially different formulation or dosage form.

Can Contrave be reformulated as a capsule?

Potentially, but a capsule or multiparticulate product would face separate bioequivalence, manufacturing, labeling and patent analyses. A dosage-form change would not automatically avoid method or formulation claims.

What is the most valuable excipient innovation for Contrave?

A robust controlled-release matrix that maintains dissolution similarity across manufacturing scale, compression conditions and storage is the highest-value opportunity. The commercial advantage comes from process tolerance and regulatory reproducibility, not from replacing a single commodity excipient.

References

1. U.S. Food and Drug Administration. (2023). Contrave (naltrexone hydrochloride and bupropion hydrochloride) extended-release tablets: Prescribing information.
2. U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations, Orange Book: NDA 200063.
3. U.S. Food and Drug Administration. (2024). Abbreviated new drug application approvals and 180-day exclusivity provisions.
4. Currax Pharmaceuticals LLC. (2024). Contrave product and corporate information.
5. U.S. Food and Drug Administration. (2024). Drugs@FDA: FDA-approved drugs and obesity-treatment labeling information.