List of Excipients in Branded Drug ALVIMOPAN

Generic Drugs Containing ALVIMOPAN

Company	Ingredient	NDC	Excipient
Hikma Pharmaceuticals USA Inc	alvimopan	0054-0668	AMMONIA
Hikma Pharmaceuticals USA Inc	alvimopan	0054-0668	FD&C BLUE NO. 1
Hikma Pharmaceuticals USA Inc	alvimopan	0054-0668	FERROSOFERRIC OXIDE
Hikma Pharmaceuticals USA Inc	alvimopan	0054-0668	GELATIN

What are the Most Frequently-Used Excipients in ALVIMOPAN?

# Of NDCs	Excipient
4	AMMONIA
3	FD&C BLUE NO. 1
1	FD&C RED NO. 3
4	FERROSOFERRIC OXIDE

Alvimopan Excipient Strategy and Commercial Opportunities

Last updated: September 16, 2026

Alvimopan is a specialized hospital-use gastrointestinal drug with limited volume but defensible commercial niches. The strongest excipient opportunities are generic capsule development, gelatin-free and lactose-free presentations, improved powder-flow control, packaging stability, and supply-chain differentiation. The product’s main commercial constraint is regulatory: alvimopan is restricted to short-term inpatient use under the Entereg Risk Evaluation and Mitigation Strategy, or REMS. It is not a conventional chronic-use pharmaceutical market.

What is alvimopan and how is it administered?

Alvimopan is an orally active, peripherally acting mu-opioid receptor antagonist. It is used to accelerate recovery of gastrointestinal function after partial bowel resection with primary anastomosis. The drug counteracts opioid-related gastrointestinal hypomotility without materially reversing centrally mediated analgesia at the labeled dose.[1]

Attribute	Alvimopan
Brand	Entereg
Active ingredient	Alvimopan
Strength	12 mg capsule
Route	Oral
Primary use	Accelerated gastrointestinal recovery after bowel resection
Dose	12 mg before surgery, followed by 12 mg twice daily
Maximum labeled exposure	15 doses
Setting	Inpatient hospital use
Regulatory pathway	FDA-approved NDA
Key restriction	REMS and hospital-use controls
Main competitor	No direct branded pharmacologic equivalent; routine postoperative-care alternatives include opioid-sparing protocols and standard bowel-recovery management

The approved dosing structure sharply limits annual patient exposure. A typical patient receives one preoperative dose and postoperative doses during a short hospitalization. This reduces the addressable volume compared with chronic gastrointestinal drugs but makes reliable hospital procurement and formulary access commercially important.

What excipients are used in alvimopan capsules?

Entereg is a hard oral capsule containing alvimopan monohydrate equivalent to 12 mg of alvimopan. The formulation uses conventional capsule excipients intended to support powder blending, content uniformity, capsule manufacture, disintegration, and chemical stability.[1]

Public product information identifies excipient categories that include:

• Diluent and bulking excipients, including lactose monohydrate and microcrystalline cellulose.
• Disintegrant, including crospovidone.
• Binder or granulation aid, including povidone.
• Glidant, including colloidal silicon dioxide.
• Lubricant, including magnesium stearate.
• Surfactant or wetting aid, including sodium lauryl sulfate.
• Capsule-shell materials, including gelatin and titanium dioxide.
• Colorant components used in the capsule shell.

The precise inactive-ingredient declaration should be confirmed against the current FDA labeling record and the approved manufacturer’s package insert before development or procurement decisions. Excipient changes can affect powder flow, dissolution, content uniformity, capsule robustness, impurity formation, and bioequivalence.

Why the low-dose-to-fill-weight ratio matters

Alvimopan has a 12 mg drug load. The active ingredient is therefore only one component of the total capsule fill, and the formulation must control segregation during blending and encapsulation. A generic manufacturer may use a larger excipient matrix than the reference product to achieve acceptable content uniformity and manufacturing yield.

The highest-risk technical variables are:

1. Particle-size mismatch between alvimopan and the principal diluent.
2. Electrostatic segregation during transfer and encapsulation.
3. Over-lubrication with magnesium stearate.
4. Interaction between surfactant content and dissolution.
5. Moisture migration between the powder fill and gelatin shell.
6. Colorant and capsule-shell differences that affect supply or patient acceptance.

A robust development program should evaluate direct blending against dry granulation, compare multiple grades of microcrystalline cellulose and lactose, and establish blend-uniformity limits tighter than the minimum release specification.

Which excipient strategies create commercial opportunities?

The most practical opportunities are incremental formulations that preserve the approved 12 mg capsule while removing avoidable supply, tolerability, or manufacturing constraints.

Lactose-free alvimopan capsules

A lactose-free formulation could address hospitals and patients seeking to avoid lactose-derived excipients. The commercial value is likely limited because the course is short and the capsule is administered in a controlled hospital setting. It may still help differentiate a generic product in institutional tenders.

Potential replacement systems include:

• Microcrystalline cellulose and mannitol.
• Microcrystalline cellulose with dibasic calcium phosphate.
• Spray-dried mannitol for improved flow.
• Low-moisture starch or co-processed cellulose systems.

The primary development risk is dissolution drift. Lactose replacement changes density, porosity, water uptake, and compaction behavior.

Gelatin-free capsules

A hard hypromellose capsule could provide a vegetarian and gelatin-free alternative. The substitution is technically feasible but requires evaluation of:

• Shell moisture content.
• Oxygen and water-vapor transmission.
• Capsule brittleness.
• Machine compatibility.
• Fill-weight consistency.
• Stability under hospital warehouse conditions.

A hypromellose shell could be commercially useful for manufacturers with a broader vegetarian or non-animal-derived portfolio. It is less likely to command a large premium in a short-duration inpatient product unless a hospital system has a procurement-wide excipient policy.

Colorant-free or simplified capsule shells

Colorant removal can reduce dependence on specific dye suppliers and simplify global registration. It may also help manufacturers avoid regional differences in permitted color additives. The tradeoff is visual differentiation. A plain white or naturally opaque capsule may require stronger packaging controls to reduce dispensing errors.

Improved flow and content uniformity

This is the most defensible technical opportunity. Alvimopan’s low dose makes content uniformity central to manufacturing economics. A co-processed excipient system could reduce:

• Blend time.
• Rework.
• Encapsulation weight variation.
• Dust generation.
• Segregation after transfer.
• Batch-release failures.

A manufacturer can create value without changing the active ingredient by improving process capability and reducing cost per released batch. The resulting intellectual-property position is more likely to arise from process parameters, excipient ratios, or manufacturing controls than from the basic use of a conventional filler.

Moisture and stability optimization

Alvimopan capsules must remain stable through manufacturing, distribution, and hospital storage. A low-moisture excipient system, high-barrier blister, or desiccant-supported bottle may reduce degradation risk.

The commercial choice is between formulation and packaging:

Strategy	Benefit	Cost or risk
Low-moisture excipients	Reduces water-driven degradation	May worsen flow or compaction
Hypromellose shell	Avoids gelatin and may improve animal-origin profile	Requires separate shell qualification
Alu-Alu blister	Strong moisture and oxygen barrier	Higher packaging cost
HDPE bottle with desiccant	Familiar hospital packaging	More headspace and handling variability
Unit-dose blister	Supports inpatient administration control	Higher packaging and serialization cost

Because alvimopan is administered in hospitals, unit-dose packaging can have a stronger commercial rationale than it would for an outpatient product. It can support medication-administration workflows, inventory control, and prevention of unnecessary discharge dispensing.

What regulatory pathway applies to an alvimopan generic?

A conventional generic would generally use the abbreviated new drug application pathway under section 505(j) of the Federal Food, Drug, and Cosmetic Act. The product would need to match the reference product in active ingredient, strength, dosage form, route of administration, and labeling, subject to permitted differences.[2]

The principal development requirements are:

• Pharmaceutical equivalence.
• Demonstration of bioequivalence.
• Comparative dissolution.
• Stability data.
• Manufacturing-process validation.
• Container-closure qualification.
• Compliance with current good manufacturing practice.
• Compliance with applicable REMS requirements.

A capsule-shell change, colorant change, or inactive-ingredient substitution does not automatically make a product ineligible for an ANDA. The effect on bioequivalence, safety, quality, and labeling must be addressed in the application.

A formulation with a materially different clinical purpose, delivery system, or dosing concept could require a 505(b)(2) application rather than an ANDA. That pathway is less attractive for a drug used for a short inpatient course unless the reformulation produces a clear operational or clinical benefit.

What is the FDA regulatory and REMS status of alvimopan?

The major commercial barrier is the Entereg REMS. FDA restricted alvimopan because of concern about myocardial infarction observed in long-term clinical exposure, even though the approved use is short term.[3]

The REMS limits distribution and use to hospitals that enroll in the program. Key controls include:

• Hospital enrollment.
• Prescriber and pharmacy compliance.
• Inpatient administration.
• A maximum of 15 doses for an individual patient.
• Prohibition on dispensing for outpatient use.

A generic manufacturer would need to evaluate whether FDA requires participation in the same REMS system, a comparable REMS, or another risk-management arrangement. The risk-control structure limits direct-to-consumer commercialization and favors hospital contracting, specialty distribution, and institutional account management.

When does alvimopan lose exclusivity and how do patents affect entry?

Alvimopan’s commercial protection has multiple components: FDA regulatory exclusivity, patent rights, Orange Book listings, and the practical protection created by the REMS-controlled hospital market.

The core compound and original product patents are distinct from later patents covering:

• Solid dosage forms.
• Capsule compositions.
• Stabilized formulations.
• Manufacturing methods.
• Treatment methods.
• Packaging or administration systems.

An ANDA applicant must address eligible Orange Book patents through certification. A Paragraph IV certification can trigger patent litigation if the patent owner sues within the statutory period. Paragraph III certification would defer approval until patent expiration. A Section viii statement may be relevant for a method-of-use patent if the applicant omits the protected indication from labeling.[2]

The commercially relevant patent review should examine:

Review item	Commercial implication
Compound patent	May block basic alvimopan entry if unexpired
Formulation patent	Can require a non-infringing excipient design
Method-of-use patent	May permit a label carve-out or require litigation
Manufacturing patent	Can require an alternate process
Orange Book listing	Determines certification and litigation exposure
Pediatric exclusivity	Can extend certain patent-related restrictions
Patent-term extension	May extend enforceable protection beyond ordinary term
REMS obligations	Can add regulatory cost after patent barriers fall

Patent expiry dates should be taken from the FDA Orange Book and the relevant United States Patent and Trademark Office records, not inferred from the original approval date.[2,4] A generic strategy based on a different capsule shell or excipient system is most valuable when formulation patents remain active but the design-around is technically credible.

What patent strength does an alvimopan excipient strategy have?

A simple substitution of lactose, gelatin, or colorant usually has weak standalone patent value. The composition becomes more protectable when it combines a defined excipient system with measurable performance advantages.

Potential claim categories include:

• Alvimopan with a specified particle-size distribution.
• A defined ratio of active ingredient to diluent.
• A low-moisture composition with specified water activity.
• A co-processed excipient system that improves content uniformity.
• A capsule with defined dissolution limits across pH conditions.
• A formulation with reduced impurity formation during accelerated stability testing.
• A manufacturing process that achieves specified blend-uniformity and yield parameters.

The strongest commercial filing would link composition to performance. Claims limited to "alvimopan in a capsule with a conventional filler" are more vulnerable to obviousness and written-description challenges than claims tied to unexpected stability, dissolution, or manufacturability results.

Which companies are likely to compete in alvimopan?

Competition is likely to come from established generic manufacturers with hospital portfolios rather than consumer-health companies. The relevant capabilities are:

• ANDA development.
• Controlled-substance-adjacent hospital distribution experience, although alvimopan itself is not an opioid.
• REMS compliance.
• Institutional contracting.
• Low-volume specialty manufacturing.
• Reliable capsule and packaging supply.

Potential competitors include generic companies with gastrointestinal, perioperative, or hospital products. The competitive field may remain narrow because the market is small, procurement is concentrated, and a new entrant must support regulatory risk management without the volume of a major chronic-use product.

A manufacturer with an existing hospital sales force can gain more value from alvimopan than a low-cost producer that lacks formulary access. The product is operationally a hospital account product, not a broad retail generic.

What generic launch risks exist for alvimopan?

Limited market size

The short treatment duration caps unit demand. A manufacturer must model hospital procedure volume, bowel-resection prevalence, formulary adoption, and dose utilization rather than relying on prescription-count forecasts.

REMS implementation

Failure to align distribution, enrollment, pharmacy controls, and prescriber processes can delay launch or create compliance exposure.

Hospital price pressure

Institutional buyers may treat alvimopan as a cost-control target because alternatives include enhanced recovery protocols, opioid minimization, early feeding, ambulation, and conventional postoperative management.

Clinical substitution

Hospitals may reduce alvimopan use even without generic competition if enhanced recovery after surgery protocols lower opioid exposure and shorten ileus duration.

Supply reliability

A low-volume product can be vulnerable to manufacturing interruptions. Hospitals may value dual sourcing and dependable fill rates over modest unit-price discounts.

Label and patent disputes

A formulation change that appears commercially minor can affect patent certification, labeling, or bioequivalence. The lowest-cost formulation is not necessarily the lowest-risk launch design.

How does alvimopan compare with broader gastrointestinal drug opportunities?

Factor	Alvimopan	Chronic gastrointestinal drugs
Treatment duration	Usually several days	Months or years
Main customer	Hospital and surgical service	Retail, specialty, or hospital
Volume	Low	Moderate to high
Pricing pressure	Institutional contracting	Pharmacy benefit and generic competition
Excipient differentiation	Manufacturing and compliance driven	Patient tolerability and dosage-form driven
REMS impact	Material	Often limited or absent
Formulation premium	Limited	Greater if adherence or delivery improves
Commercial advantage	Supply reliability and hospital access	Brand, adherence, or broad payer access

Alvimopan is less attractive as a standalone blockbuster opportunity. It is more attractive as part of a hospital-generic portfolio, a contract-manufacturing platform, or a targeted formulation-and-IP program.

What licensing and partnership opportunities exist?

Licensing opportunities are most credible in four areas:

1. Regional commercialization: A rights holder can license alvimopan to a generic company with hospital coverage in a particular country.
2. REMS and distribution support: A manufacturer can partner with an established hospital distributor to manage enrollment and controlled dispensing.
3. Excipient or capsule technology: A specialty excipient supplier can license a low-moisture, gelatin-free, or content-uniformity platform.
4. Manufacturing transfer: A company with an approved product can transfer production to a contract manufacturer with lower batch costs or better supply redundancy.

The small market argues for milestone-light agreements, supply-based economics, or portfolio bundling rather than large upfront payments. A licensing deal should allocate responsibility for patent certifications, REMS administration, shortage reporting, and hospital contracting.

What geographic opportunities exist for alvimopan?

The United States is distinctive because of the Entereg REMS and the FDA’s specific inpatient-use framework. Other jurisdictions may impose different pharmacovigilance, labeling, or reimbursement conditions. International opportunity depends on:

• Approval status in the target country.
• Patent and supplementary protection certificate position.
• Local hospital procurement.
• Acceptance of the clinical indication.
• Availability of enhanced-recovery surgical protocols.
• Local excipient restrictions.
• Capsule-shell and colorant requirements.

A global excipient strategy should avoid dependence on a single dye, animal-derived shell, or region-specific excipient grade. A common lactose-free and gelatin-free platform may simplify registration, but the added cost must be justified by actual market access.

Key Takeaways

• Alvimopan is a short-course, inpatient gastrointestinal drug with a narrow but specialized commercial market.
• The most practical formulation opportunities are lactose-free, gelatin-free, low-moisture, colorant-simplified, and improved-flow capsules.
• Content uniformity and manufacturing yield are more commercially important than patient-facing formulation differentiation.
• The Entereg REMS materially affects distribution, hospital contracting, and launch economics.
• Generic entry requires coordinated analysis of ANDA requirements, Orange Book patents, Paragraph IV exposure, formulation patents, and REMS obligations.
• Patent value is strongest when an excipient system is linked to measurable improvements in stability, dissolution, content uniformity, or manufacturing performance.
• The best commercial vehicle is a hospital-generic portfolio or licensing arrangement, not a standalone mass-market launch.
• Unit-dose packaging, dependable supply, and hospital account coverage may create more value than a marginal excipient change.

FAQs

Is alvimopan a good candidate for a lactose-free generic?

Yes. A lactose-free capsule is technically feasible, but the commercial value depends on hospital procurement policies and whether the replacement excipient system maintains bioequivalence, dissolution, stability, and content uniformity.

Can alvimopan be reformulated as an extended-release product?

An extended-release product would have limited commercial rationale because the approved use is short term and the dose is already administered only around the surgical period. A materially different release profile would likely require a development pathway beyond a conventional ANDA.

Does a gelatin-free alvimopan capsule have strong patent potential?

The shell substitution alone generally has limited patent strength. Patentability improves when the gelatin-free design solves a defined stability, moisture, manufacturing, or dissolution problem and is supported by comparative data.

Are alvimopan tablets commercially preferable to capsules?

Not necessarily. Tablets could reduce dependence on capsule-shell suppliers, but they would require evaluation of compression, disintegration, dissolution, dose uniformity, and regulatory equivalence. A capsule remains the lower-risk generic target because it matches the reference dosage form.

What is the main reason hospitals may not adopt a lower-cost alvimopan generic?

Hospitals may prioritize REMS compliance, supply continuity, formulary integration, and total postoperative-care economics over the lowest acquisition price. Enhanced recovery protocols and opioid-sparing practices can also reduce demand for alvimopan.

References

1. U.S. Food and Drug Administration. (2023). Entereg (alvimopan) capsules, 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. (2014). Entereg REMS: Risk Evaluation and Mitigation Strategy.
4. United States Patent and Trademark Office. (2024). Patent term adjustment and patent term extension information.