List of Excipients in Branded Drug CHLORDIAZEPOXIDE HYDROCHLORIDE/CLIDINIUM BROMIDE

Generic Drugs Containing CHLORDIAZEPOXIDE HYDROCHLORIDE/CLIDINIUM BROMIDE

Company	Ingredient	NDC	Excipient
ECI Pharmaceuticals LLC	chlordiazepoxide hydrochloride and clidinium bromide	51293-696	AMMONIA
ECI Pharmaceuticals LLC	chlordiazepoxide hydrochloride and clidinium bromide	51293-696	D&C YELLOW NO. 10
ECI Pharmaceuticals LLC	chlordiazepoxide hydrochloride and clidinium bromide	51293-696	FD&C GREEN NO. 3
ECI Pharmaceuticals LLC	chlordiazepoxide hydrochloride and clidinium bromide	51293-696	FERROSOFERRIC OXIDE
ECI Pharmaceuticals LLC	chlordiazepoxide hydrochloride and clidinium bromide	51293-696	GELATIN
ECI Pharmaceuticals LLC	chlordiazepoxide hydrochloride and clidinium bromide	51293-696	LACTOSE MONOHYDRATE
ECI Pharmaceuticals LLC	chlordiazepoxide hydrochloride and clidinium bromide	51293-696	POTASSIUM HYDROXIDE

What are the Most Frequently-Used Excipients in CHLORDIAZEPOXIDE HYDROCHLORIDE/CLIDINIUM BROMIDE?

# Of NDCs	Excipient
2	AMMONIA
2	D&C YELLOW NO. 10
2	FD&C GREEN NO. 3
2	FERROSOFERRIC OXIDE
2	GELATIN
2	LACTOSE MONOHYDRATE
2	POTASSIUM HYDROXIDE

Chlordiazepoxide Hydrochloride/Clidinium Bromide Excipient Strategy and Commercial Opportunities

Last updated: August 7, 2026

Chlordiazepoxide hydrochloride/clidinium bromide is a legacy fixed-dose oral capsule marketed in the United States as Librax and through generic equivalents. The standard strength is 5 mg chlordiazepoxide hydrochloride and 2.5 mg clidinium bromide per capsule. Its commercial opportunity is primarily in reliable generic supply, excipient differentiation, controlled-substance compliance, and lifecycle reformulation rather than patent exclusivity.

The product has no meaningful biosimilar risk because it is a small-molecule combination. The main barriers are regulatory compliance, control of a Schedule IV benzodiazepine, formulation uniformity at a low active load, and maintaining capsule stability and dissolution across suppliers.

What is chlordiazepoxide hydrochloride/clidinium bromide?

Chlordiazepoxide hydrochloride/clidinium bromide combines a benzodiazepine with an anticholinergic agent.

Attribute	Chlordiazepoxide hydrochloride/clidinium bromide
Dosage form	Immediate-release oral capsule
Typical strength	5 mg/2.5 mg
Benzodiazepine component	Chlordiazepoxide hydrochloride
Anticholinergic component	Clidinium bromide
U.S. reference brand	Librax
FDA application	NDA 012750
Controlled-substance status	Schedule IV because of chlordiazepoxide
Primary labeled uses	Adjunctive treatment of peptic ulcer disease and irritable bowel syndrome; treatment of acute enterocolitis
Biosimilar pathway	Not applicable
Main generic pathway	ANDA referencing the listed drug
Principal commercial risk	Supply, compliance, and reimbursement pressure rather than patent expiry

Chlordiazepoxide produces central nervous system depressant effects. Clidinium bromide reduces gastrointestinal smooth-muscle spasm and secretion through anticholinergic activity. The combination is therefore sensitive to labeling, abuse-risk controls, geriatric safety, anticholinergic burden, and interactions with opioids and other central nervous system depressants (FDA, 2023).

What excipients are used in the reference and generic products?

Excipient composition varies by manufacturer and should be assessed at the product-specific National Drug Code level. Reference and generic capsules commonly use lactose or another diluent, starch or a related disintegrant, a lubricant or glidant, and a hard capsule shell with colorants.

The commercial formulation issues are:

1. Low-dose content uniformity for both active ingredients.
2. Uniform distribution of clidinium bromide and chlordiazepoxide hydrochloride in the blend.
3. Stable capsule fill weight despite low total active mass.
4. Consistent disintegration and dissolution after storage.
5. Control of moisture, which can affect powder flow, capsule shell performance, and assay stability.
6. Management of inactive-ingredient labeling for lactose-sensitive, color-sensitive, vegetarian, or religiously restricted patients.

What excipient functions are most important?

Excipient function	Commercial objective	Key formulation concern
Diluent	Achieve a practical capsule fill weight	Avoid segregation and excessive capsule size
Disintegrant	Provide rapid capsule plug breakup	Excessive concentration can alter flow or dissolution
Glidant	Improve powder flow	Over-lubrication may slow dissolution
Lubricant	Prevent sticking and improve encapsulation	Hydrophobic lubricants may reduce wetting
Moisture control	Protect assay and physical stability	Hygroscopic materials can increase variability
Capsule shell	Provide appearance and unit protection	Gelatin brittleness or cross-linking can affect performance
Colorant	Support product identification	Creates market-access issues for color-free products

An excipient strategy should begin with a full comparison of the reference product, approved generics, and target-market requirements. The relevant data include qualitative and quantitative composition, capsule shell source, moisture content, particle-size distribution, blend uniformity, dissolution profile, and stability under ICH conditions.

Which excipient strategies offer the strongest commercial opportunities?

Lactose-free capsules

Lactose-free positioning is one of the clearest opportunities. Lactose is widely used in oral solid dosage forms, but a lactose-free capsule can address patient and institutional purchasing preferences. The opportunity is strongest where the product is supplied through hospital formularies, specialty pharmacies, long-term-care providers, or export markets with strict inactive-ingredient requirements.

A lactose-free formulation must preserve powder density, flow, and content uniformity without substantially changing dissolution. Mannitol, microcrystalline cellulose, starch-based materials, or selected dibasic phosphate systems may be considered, but each changes bulk density and compaction behavior.

Colorant-free products

A colorant-free capsule can differentiate the product without changing the active ingredients. The commercial value is likely higher in institutional and international channels than in a heavily commoditized retail generic market.

The principal risk is identification. A color-free product must use imprinting, capsule geometry, packaging controls, or other compliant means to reduce dispensing errors.

Vegetarian or HPMC capsules

Hydroxypropyl methylcellulose capsules can address vegetarian, religious, and supply-chain preferences. HPMC shells also offer a potential solution where gelatin sourcing or storage conditions create a commercial problem.

The development burden includes capsule-machine compatibility, shell moisture behavior, fill-weight consistency, dissolution equivalence, and stability under high humidity.

Low-moisture formulations

A low-moisture powder system may improve stability and reduce capsule-shell interactions. This strategy is relevant when the active ingredients or selected excipients show moisture sensitivity. It can also support distribution in hot and humid markets.

The main risk is poor powder flow. A formulation with low water activity can become electrostatic or cohesive, increasing weight variation and segregation during encapsulation.

Sprinkle or alternative oral delivery

A sprinkle formulation could improve administration for patients who cannot swallow capsules. This opportunity is technically complex because opening the capsule may change exposure, taste, handling, and occupational safety. Chlordiazepoxide is a controlled substance, and any alternative administration method would require clear labeling, dose-integrity data, and FDA review.

A sprinkle product should not be commercialized on the assumption that the contents may be freely mixed with food. That use would require product-specific regulatory support.

What formulation patents protect the combination?

No commercially significant, enforceable composition-of-matter patent is expected to protect this decades-old combination. The original combination product predates the modern patent and Orange Book framework by many years.

The remaining intellectual-property opportunity is more likely to involve:

• A novel excipient system.
• A modified-release or abuse-deterrent dosage form.
• A specific capsule-shell or moisture-control technology.
• A new method of administration.
• A manufacturing process that materially improves content uniformity or stability.
• A new therapeutic use, if legally and clinically supportable.

A formulation patent would need meaningful technical differentiation. A claim limited to substituting one conventional diluent for another would face substantial obviousness risk. Stronger claims would require comparative data showing an unexpected result, such as improved stability, reduced impurity formation, superior dissolution after accelerated storage, or materially improved dose uniformity.

When does chlordiazepoxide/clidinium bromide lose exclusivity?

The product lost practical market exclusivity long ago. Librax is a legacy product, and generic competition is permitted through the ANDA pathway if an applicant demonstrates pharmaceutical equivalence, bioequivalence, chemistry-manufacturing-controls compliance, and labeling conformity.

Exclusivity category	Status
New chemical entity exclusivity	Expired
Orphan exclusivity	Not applicable
Pediatric exclusivity	No current commercial significance identified
Reference-product market exclusivity	Expired
Composition-of-matter patent	Expired or not commercially relevant
Formulation patent	No broad active protection identified
Method-of-use protection	No broad active protection identified
Generic entry	Legally available, subject to ANDA approval

The FDA Orange Book is the governing source for current patent and exclusivity entries. For NDA 012750, the commercial protection profile is consistent with a mature, genericized product rather than an actively protected innovator product (FDA, 2024a).

What is the Orange Book status of Librax?

Librax is listed as the reference product associated with NDA 012750. The relevant Orange Book analysis is:

• The active ingredients are old and widely known.
• The product is an immediate-release capsule.
• No current market position depends on unexpired basic compound patents.
• Generic applicants can pursue approval without waiting for a modern brand exclusivity period.
• Any listed patent would need to be reviewed by patent number, expiration date, and the applicable certification code.

The absence of meaningful current Orange Book exclusivity shifts the competitive focus to approved suppliers, manufacturing reliability, contract pricing, and product availability.

Are Paragraph IV challenges relevant?

Paragraph IV risk is limited because the principal product protection has expired. An ANDA applicant would more likely rely on Paragraph III or Paragraph IV only if a current, listed patent affected approval timing.

For a legacy product, the practical regulatory risks are different:

• Failure to match the reference labeling.
• Inadequate stability data.
• Inconsistent dissolution.
• Incomplete controlled-substance procedures.
• Deficiencies in active-pharmaceutical-ingredient qualification.
• Manufacturing-site observations.
• Shortages caused by a limited number of qualified suppliers.

No major current Paragraph IV campaign or settlement framework is central to this combination based on the public FDA product and Orange Book records cited here.

What patent litigation and settlement agreements affect the product?

No major active patent litigation or high-value generic settlement is central to the commercial position of chlordiazepoxide hydrochloride/clidinium bromide. The product's legal exposure is more likely to arise from:

• Controlled-substance distribution practices.
• Product-liability claims involving sedation, falls, dependence, or drug interactions.
• Anticholinergic adverse effects.
• Manufacturing and quality systems.
• Trademark or trade-dress disputes involving Librax.

Patent litigation is not the principal barrier to entry. A company evaluating acquisition or licensing should place greater weight on regulatory history, DEA controls, supplier qualification, product complaints, and reimbursement data.

How strong is the patent estate for chlordiazepoxide/clidinium bromide?

The patent estate is weak for exclusivity purposes but potentially usable for narrow lifecycle inventions.

Patent category	Estimated strategic value
Original active-ingredient patents	None for current exclusivity
Fixed-dose combination patent	Low
Conventional immediate-release formulation	Low
Novel excipient platform	Moderate if supported by data
Modified release	Moderate to high, but development risk is substantial
Abuse-deterrent formulation	Potentially high, with significant technical and regulatory burden
Alternative capsule shell	Low to moderate
New method of use	Fact-dependent and clinically constrained
Manufacturing-process patent	Moderate if it produces measurable quality advantages

A new patent strategy should focus on claims that can support a distinct product and withstand an obviousness challenge. Patent value would be limited if the product remains therapeutically and commercially indistinguishable from low-cost generics.

What FDA regulatory status applies?

The product is an FDA-approved prescription combination. Chlordiazepoxide triggers Schedule IV controlled-substance obligations under the Controlled Substances Act. Manufacturers and distributors must maintain appropriate registration, inventory, recordkeeping, security, ordering, and reporting systems (21 C.F.R. Parts 1301-1305).

The label also carries safety concerns associated with benzodiazepines, including abuse, misuse, addiction, physical dependence, withdrawal reactions, and potentially fatal respiratory depression when combined with opioids. These risks affect packaging, pharmacist communication, prescribing controls, postmarket surveillance, and institutional formulary decisions (FDA, 2020; FDA, 2023).

A new formulation could require an ANDA if it remains pharmaceutically equivalent to the reference product. A changed strength, dosage form, release profile, route, or therapeutic claim could require a different FDA pathway, including a 505(b)(2) application.

What manufacturing and intellectual-property barriers exist?

The manufacturing barriers are moderate rather than high.

Key technical barriers

• Accurate blending of two low-dose active ingredients.
• Prevention of segregation during transfer and encapsulation.
• Control of capsule fill-weight variation.
• Verification of assay and content uniformity.
• Dissolution matching against the reference product.
• Stable supply of qualified APIs.
• Controlled-substance reconciliation and security.
• Management of nitrosamine, elemental impurity, residual-solvent, and microbial risks where applicable.

API and supply-chain considerations

Chlordiazepoxide hydrochloride and clidinium bromide are mature APIs, so multiple global sources may exist. The commercial risk is not necessarily scarcity. It is maintaining consistent quality, regulatory documentation, impurity control, and uninterrupted supply from approved sites.

A dual-source strategy can reduce supply risk but may require additional comparability work. API changes can affect particle size, bulk density, blend uniformity, dissolution, and capsule fill weight even when the API meets compendial specifications.

How does this product compare with competing gastrointestinal therapies?

Product category	Competitive advantage	Limitation versus the combination
Antispasmodic-only products	Lower controlled-substance burden	No benzodiazepine component
Benzodiazepine-only products	Simpler formulation	No direct anticholinergic gastrointestinal effect
Proton-pump inhibitors	Strong acid-suppression role	Not a direct substitute for spasm-related symptoms
Anticholinergic agents	Lower formulation complexity	May lack the anxiolytic component
IBS-directed therapies	Disease-specific positioning	Often target narrower patient populations
Nonprescription digestive products	Lower access barrier	Different evidence and pharmacologic profile

The combination's differentiation is limited by its older clinical positioning and safety profile. Its commercial value is strongest where prescribers still use the established combination and where supply reliability matters.

What generic launch scenarios exist?

Scenario 1: Low-cost standard generic

This is the most likely strategy. The manufacturer uses a conventional immediate-release capsule and competes through price, wholesaler access, and reliable availability.

Scenario 2: Excipient-differentiated generic

A lactose-free, color-free, or vegetarian capsule can support institutional contracts and selected pharmacy channels. The product remains a standard immediate-release capsule but offers a practical inactive-ingredient distinction.

Scenario 3: Premium lifecycle product

A new capsule shell, modified-release profile, or abuse-deterrent platform could support higher pricing. Development cost, FDA review, clinical requirements, and payer resistance make this strategy materially riskier.

Scenario 4: Supply-constrained niche product

A manufacturer can target markets underserved by current suppliers. The opportunity depends on actual shortage history, competitor discontinuations, and procurement contracts rather than patent exclusivity.

What revenue exposure exists?

Public product-level revenue for Librax and generic chlordiazepoxide hydrochloride/clidinium bromide is not generally reported separately by major manufacturers. The product should therefore be treated as a mature, low-growth prescription opportunity unless a company has proprietary dispensing, wholesaler, or contract data.

The principal revenue variables are:

• Number of active generic suppliers.
• Annual prescription volume.
• Average selling price after rebates.
• Medicaid and Medicare reimbursement.
• Shortage-driven price increases.
• Brand-versus-generic substitution.
• Controlled-substance distribution restrictions.
• Institutional contract wins.
• Incremental value of excipient differentiation.

The likely commercial model is volume-based and supply-sensitive. Patent-protected pricing is unavailable.

What licensing opportunities exist?

The most credible licensing opportunities involve:

1. A ready-to-file ANDA with complete bioequivalence and CMC packages.
2. A differentiated lactose-free or color-free formulation.
3. A qualified source of both APIs with regulatory support.
4. A contract manufacturing arrangement with Schedule IV capability.
5. A regional commercialization license in markets where the combination remains prescribed.
6. A formulation technology that improves stability or content uniformity.

A licensing deal should allocate responsibility for DEA compliance, API qualification, recalls, pharmacovigilance, shortage reporting, and changes to the approved manufacturing process. A conventional Librax-equivalent product is unlikely to justify a large upfront payment without documented market access or supply scarcity.

What are the geographic opportunities?

The combination may have commercial relevance in the United States and selected international markets, but approval status, scheduling, labeling, and clinical use differ by jurisdiction.

Region	Main opportunity	Principal issue
United States	ANDA-based generic supply and excipient differentiation	Schedule IV controls and mature pricing
European markets	Potential legacy-product or national authorization opportunity	Benzodiazepine and anticholinergic restrictions
Latin America	Established gastrointestinal prescribing in some markets	Local registration and controlled-substance rules
Middle East and Africa	Import and distributor opportunities	Registration, supply reliability, and pharmacovigilance
Asia-Pacific	Contract manufacturing and selected-market launches	Country-specific scheduling and formulation requirements

Country-level launch decisions require confirmation of whether both active ingredients are approved together, whether the combination is marketed, and whether chlordiazepoxide is subject to additional dispensing restrictions.

Key Takeaways

• Chlordiazepoxide hydrochloride/clidinium bromide is a mature, genericized immediate-release capsule.
• The standard U.S. strength is 5 mg chlordiazepoxide hydrochloride and 2.5 mg clidinium bromide.
• No meaningful current composition patent or exclusivity barrier drives the market.
• Biosimilar risk is irrelevant; generic ANDA competition is the principal pathway.
• The strongest excipient opportunities are lactose-free, color-free, vegetarian/HPMC, and improved-moisture-control formulations.
• Content uniformity, powder segregation, capsule stability, and controlled-substance compliance are the main technical barriers.
• A new formulation patent would need measurable technical advantages to have commercial value.
• Revenue is likely mature and volume-driven, with limited publicly disclosed product-level sales data.
• Licensing value is highest for an approved or near-approval generic, a differentiated capsule, or a reliable API and manufacturing platform.
• Generic launch success will depend more on supply continuity, channel access, and reimbursement than on patent strategy.

FAQs

Is chlordiazepoxide hydrochloride/clidinium bromide still commercially viable?

Yes, but primarily as a mature generic or supply-reliability product. The opportunity is limited for premium pricing unless the product solves an identifiable excipient, availability, or administration problem.

Can a lactose-free version be filed as an ANDA?

A lactose-free version may qualify for an ANDA if it remains pharmaceutically equivalent and meets FDA requirements for inactive ingredients, bioequivalence, CMC, labeling, and product performance. A material change in dosage form or release characteristics could require a different pathway.

Does clidinium bromide create a biosimilar opportunity?

No. Clidinium bromide is a small molecule, and the combination is regulated through conventional small-molecule drug pathways rather than the biosimilar framework.

Could an abuse-deterrent version obtain new patent protection?

Potentially, if the formulation uses a novel, non-obvious technology that produces a meaningful deterrent effect and supports patentable claims. FDA labeling and clinical or abuse-potential evidence could create a greater burden than for a conventional generic.

What is the most defensible commercial differentiation?

A reliable, FDA-compliant product with a lactose-free or color-free excipient profile, stable supply, and strong pharmacy-channel execution is more defensible than a minor conventional formulation change. A modified-release or abuse-deterrent product could create stronger differentiation but carries substantially higher development and regulatory risk.

References

1. U.S. Food and Drug Administration. (2020). FDA requiring boxed warning updated to improve safe use of benzodiazepine drug class. https://www.fda.gov
2. U.S. Food and Drug Administration. (2023). Librax (chlordiazepoxide hydrochloride and clidinium bromide) capsules, prescribing information.
3. U.S. Food and Drug Administration. (2024a). Approved drug products with therapeutic equivalence evaluations: Orange Book. https://www.accessdata.fda.gov/scripts/cder/ob/
4. U.S. Food and Drug Administration. (2024b). Drugs@FDA: FDA-approved drugs. https://www.accessdata.fda.gov/scripts/cder/daf/
5. Electronic Code of Federal Regulations. (2024). 21 C.F.R. Parts 1301-1305: Controlled substances. https://www.ecfr.gov