List of Excipients in Branded Drug CHLORDIAZEPOXIDE HCL AND CLIDINIUM BROMIDE

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Generic Drugs Containing CHLORDIAZEPOXIDE HCL AND CLIDINIUM BROMIDE

Company	Ingredient	NDC	Excipient
Micro Labs Limited	chlordiazepoxide hcl and clidinium bromide	42571-381	D&C YELLOW NO. 10
Micro Labs Limited	chlordiazepoxide hcl and clidinium bromide	42571-381	FD&C BLUE NO. 1
Micro Labs Limited	chlordiazepoxide hcl and clidinium bromide	42571-381	FERROSOFERRIC OXIDE
Micro Labs Limited	chlordiazepoxide hcl and clidinium bromide	42571-381	GELATIN
Micro Labs Limited	chlordiazepoxide hcl and clidinium bromide	42571-381	LACTOSE MONOHYDRATE
Micro Labs Limited	chlordiazepoxide hcl and clidinium bromide	42571-381	MAGNESIUM STEARATE

What are the Most Frequently-Used Excipients in CHLORDIAZEPOXIDE HCL AND CLIDINIUM BROMIDE?

# Of NDCs	Excipient
2	D&C YELLOW NO. 10
2	FD&C BLUE NO. 1
2	FERROSOFERRIC OXIDE
2	GELATIN
2	LACTOSE MONOHYDRATE
2	MAGNESIUM STEARATE

Chlordiazepoxide HCl and Clidinium Bromide Excipient Strategy and Commercial Opportunities

Last updated: September 26, 2026

Chlordiazepoxide hydrochloride and clidinium bromide is an established immediate-release combination marketed historically as Librax. The conventional strength contains 5 mg chlordiazepoxide hydrochloride and 2.5 mg clidinium bromide per capsule. Its commercial opportunity is primarily generic supply, differentiated capsule design, manufacturing efficiency, and product-quality positioning rather than new-molecule exclusivity.

The combination has limited active-ingredient patent protection. Commercial barriers are more likely to arise from controlled-substance compliance, formulation consistency, manufacturing reliability, bioequivalence, channel access, and physician familiarity than from enforceable patent rights.

What is chlordiazepoxide hydrochloride and clidinium bromide used for?

The combination is indicated as an adjunct in the treatment of peptic-ulcer disease and irritable bowel syndrome, according to the Librax labeling. Chlordiazepoxide is a benzodiazepine with anxiolytic activity. Clidinium bromide is an anticholinergic agent that reduces gastrointestinal smooth-muscle spasm and secretions.[1]

Parameter	Product characteristic
Active ingredients	Chlordiazepoxide hydrochloride and clidinium bromide
Common strength	5 mg / 2.5 mg per capsule
Dosage form	Immediate-release oral capsule
Historical brand	Librax
Drug category	Benzodiazepine-anticholinergic combination
Controlled-substance status	Chlordiazepoxide is a Schedule IV controlled substance in the United States
Primary commercial route	ANDA generic capsule
Main formulation challenge	Maintaining content uniformity for two low-dose active ingredients

The combination has a narrow commercial identity. Product developers must preserve the established strength, capsule presentation, release profile, and labeling framework unless pursuing a more complex regulatory strategy.

What patents protect chlordiazepoxide HCl and clidinium bromide?

No meaningful unexpired U.S. composition-of-matter patent protection is expected to remain for this legacy combination. The active ingredients and the original combination date back several decades. Any historically relevant patents would have expired long before the current generic market.

The principal U.S. intellectual-property position is therefore weak in relation to:

• Chlordiazepoxide hydrochloride as an active ingredient
• Clidinium bromide as an active ingredient
• The 5 mg/2.5 mg combination
• The conventional immediate-release capsule
• The labeled gastrointestinal indications

Potentially relevant rights would have to be assessed at the individual product and jurisdiction level. A generic manufacturer should not assume that the absence of active-ingredient patents eliminates all risk, because later patents can cover manufacturing processes, capsule presentation, trademarks, or specific formulations. Those rights are unlikely to create a strong barrier for a conventional equivalent unless they are tied to a commercially necessary feature.

How strong is the patent estate for this drug?

The patent estate is weak for a standard generic product. The combination does not have the characteristics of a modern branded medicine protected by layered composition, formulation, device, method-of-use, and manufacturing patents.

Patent category	Commercial relevance
Active-ingredient patent	Effectively expired for the legacy ingredients
Fixed-combination patent	Unlikely to block conventional generic entry
Immediate-release formulation patent	Limited expected protection
Method-of-use patent	Historical indications are unlikely to create meaningful current exclusivity
Manufacturing patent	Could affect a specific process but is unlikely to block all alternatives
Capsule-color or appearance patent	Usually not a substantive entry barrier
Trademark rights	Relevant to branding, not generic approval
Excipient-specific patent	Possible for a differentiated formulation, but not expected to cover the ordinary product

A new excipient system could create patentable subject matter only if it produces a defensible technical effect, such as improved stability, reduced degradation, enhanced content uniformity, controlled moisture exposure, or a clinically meaningful administration advantage. Routine substitutions among lactose, starch, cellulose, talc, and magnesium stearate are generally weak candidates for valuable patent protection.

When does chlordiazepoxide and clidinium lose exclusivity?

The product’s practical exclusivity has already expired. The original brand and legacy combination are not protected by modern new-drug exclusivity periods.

Exclusivity type	Status
New chemical entity exclusivity	Expired
Five-year NCE exclusivity	Not relevant to a legacy product
Three-year clinical-investigation exclusivity	No current commercial significance
Orphan exclusivity	Not applicable
Pediatric exclusivity	No known current commercial effect
Active-ingredient patent exclusivity	Expired or commercially inactive
Generic entry pathway	Available through an ANDA, subject to FDA requirements

The commercial question is therefore not when exclusivity ends. It is whether an applicant can obtain approval, source compliant controlled-substance material, demonstrate bioequivalence, and compete profitably in a small legacy market.

What is the FDA regulatory and Orange Book status?

Librax was approved as an NDA product, with chlordiazepoxide hydrochloride and clidinium bromide in capsule form. FDA-approved generic products may be listed under separate abbreviated applications. Orange Book status can change as applications are withdrawn, discontinued, or updated, so product-level verification is required before filing or transaction execution.[2]

The regulatory structure has four practical implications:

1. An ANDA applicant generally must reference the applicable listed drug and meet sameness requirements for active ingredients, strength, dosage form, route, and conditions of use.
2. The applicant must address any Orange Book-listed patents or exclusivity associated with the selected reference product.
3. The product must satisfy requirements applicable to a Schedule IV benzodiazepine ingredient.
4. Labeling, pharmacokinetics, impurity controls, and stability must support the specific capsule product submitted.

The reference-product strategy matters. A company should select the reference listed drug with the clearest current marketing status and the most commercially useful labeling. An obsolete or discontinued reference product can create additional regulatory and supply-chain complications.

Are Paragraph IV challenges relevant?

A Paragraph IV certification is unlikely to be the central issue for this legacy combination unless an applicant identifies a currently listed patent that could be infringed by its proposed product. For conventional chlordiazepoxide/clidinium capsules, the more likely certification posture is that no relevant patent is listed or that listed patents have expired.

A Paragraph IV filing would create litigation risk only if a brand owner or patent holder asserts an eligible patent. The absence of a current, enforceable formulation or method patent would reduce the value of a first-filer strategy. Any 180-day exclusivity opportunity must be evaluated against the actual Orange Book listing and the status of other approved ANDAs.

What excipients are used in chlordiazepoxide and clidinium capsules?

Inactive ingredients vary by manufacturer. Historical Librax labeling identifies conventional capsule excipients and capsule-shell components, including gelatin and colorants. Generic products may use lactose, corn starch, pregelatinized starch, microcrystalline cellulose, colloidal silicon dioxide, magnesium stearate, talc, titanium dioxide, and approved capsule colorants, depending on the manufacturer’s formulation.[1,3]

The formulation should be assessed by function rather than by ingredient name.

Excipient function	Candidate materials	Primary development issue
Diluent	Lactose, microcrystalline cellulose, mannitol, dibasic calcium phosphate	Dose uniformity and powder flow
Binder	Pregelatinized starch, povidone, hydroxypropyl cellulose	Granule strength and dissolution
Disintegrant	Crospovidone, croscarmellose sodium, sodium starch glycolate	Rapid capsule-content dispersion
Glidant	Colloidal silicon dioxide	Flow and blend uniformity
Lubricant	Magnesium stearate, sodium stearyl fumarate	Over-lubrication and dissolution impact
Moisture-control excipient	Low-moisture diluents, desiccant packaging	Stability of low-dose actives
Capsule shell	Gelatin, hydroxypropyl methylcellulose	Moisture transfer and consumer positioning
Colorant	Iron oxides, titanium dioxide, approved dyes	Product identification and regulatory status

The two active ingredients are present at low dose relative to the capsule fill. Blend segregation is therefore a central risk. Particle-size differences, density differences, electrostatic charging, and inadequate sampling can produce out-of-specification content uniformity even when assay results appear acceptable.

What excipient strategy is best for a generic manufacturer?

The lowest-risk strategy is a conventional immediate-release capsule using well-characterized, compendial excipients and a manufacturing process designed around content uniformity.

Strategy 1: Conventional lactose-starch capsule

A lactose-starch platform can provide low cost, familiar processing, and established supplier availability. It is suitable where the target reference product and local market accept lactose-containing capsules.

Key controls include:

• Active-ingredient particle-size matching
• Geometric dilution or ordered blending
• Controlled lubricant addition
• Blend sampling based on validated thief locations
• Capsule fill-weight control
• Protection against segregation during transfer and encapsulation

This is generally the strongest strategy for a price-led ANDA product.

Strategy 2: Lactose-free or low-allergen capsule

A lactose-free formulation could use microcrystalline cellulose, mannitol, or a starch-based diluent. It may support pharmacy substitution and patient-positioning claims, but the commercial value is limited unless the manufacturer can demonstrate reliable demand.

The main development risks are altered powder flow, higher fill volume, different compaction behavior, and possible changes in dissolution. A lactose-free capsule is not automatically superior. It must maintain bioequivalence and stability while preserving the reference product’s immediate-release behavior.

Strategy 3: Vegetarian or HPMC capsule

An HPMC capsule can avoid animal-derived gelatin and may support international or institutional procurement requirements. HPMC shells typically have different moisture behavior from gelatin shells. That difference can affect shell brittleness, fill stability, and the migration of moisture-sensitive materials.

This option is commercially relevant for:

• Hospital formularies with capsule-material preferences
• Export markets
• Vegetarian and religious-compliance segments
• Private-label products with differentiated packaging

It has less value in a purely commodity U.S. generic unless procurement contracts reward the distinction.

Strategy 4: Color-free capsule

A color-free or reduced-color product can simplify excipient declarations and address consumer concerns about dyes. The tradeoff is weaker visual differentiation between strengths or manufacturers. Capsule imprinting, packaging, and serialization must provide adequate product identification.

Color-free positioning is more commercially useful for direct-to-consumer or specialty-pharmacy channels than for a standard wholesale generic.

What formulation patents could protect a new product?

A new product could seek protection around a technical formulation problem rather than the known active ingredients. Potentially protectable concepts include:

• A low-dose blend that improves content uniformity
• A moisture-controlled capsule system
• A non-gelatin shell with improved stability
• A formulation that reduces chlordiazepoxide degradation products
• A composition that maintains rapid dissolution after long-term storage
• A multiparticulate or sprinkle product with validated dose delivery
• A process that reduces segregation during high-speed encapsulation

The patent value depends on measurable performance. Claims limited to replacing lactose with microcrystalline cellulose would usually have weak differentiation. Claims supported by comparative data showing lower impurity growth, tighter content-uniformity distributions, or improved stability have greater commercial and litigation value.

What manufacturing and intellectual-property barriers exist?

The main manufacturing barrier is low-dose dual-active uniformity. Chlordiazepoxide hydrochloride and clidinium bromide must be controlled independently even though they are filled into the same capsule.

Critical process parameters include:

• Active-ingredient particle-size distribution
• Blend order and blend time
• Relative density of active and excipient particles
• Environmental humidity
• Transfer-line design
• Encapsulation speed
• Fill-weight variation
• In-process assay sampling
• Packaging moisture barrier

The process may require separate premixes before final blending. Direct blending can be efficient, but only when the powder properties support reliable uniformity.

Controlled-substance handling is another barrier. Chlordiazepoxide requires inventory controls, security procedures, reconciliation, recordkeeping, and appropriate Drug Enforcement Administration compliance. These requirements raise operating costs and can reduce the number of qualified manufacturing sites.

What generic entry risks exist?

Generic entry risk is high from a legal perspective and moderate from a commercial perspective.

Risk area	Assessment
Active-ingredient patent barrier	Low
Formulation patent barrier	Low for a conventional capsule
Orange Book patent risk	Expected to be limited, subject to current listing review
ANDA technical risk	Moderate because of dual-active content uniformity
Controlled-substance compliance	Moderate to high
Manufacturing scale risk	Moderate
Pricing pressure	High
Market-size risk	High
Brand loyalty	Low to moderate
Supply interruption risk	Material in a small-supplier market

The largest risk is market economics. A generic applicant may achieve approval but still face limited volume, thin margins, wholesaler fees, and intermittent demand. A product with a lower-cost manufacturing process and reliable supply may outperform a technically differentiated product that carries excessive development or packaging costs.

Which companies are challenging the brand?

The U.S. market has historically included generic suppliers of chlordiazepoxide hydrochloride and clidinium bromide capsules. Supplier participation can change because of discontinuations, product transfers, controlled-substance allocation, and manufacturing decisions.

The relevant competitive set includes:

• ANDA holders supplying the standard 5 mg/2.5 mg capsule
• Contract manufacturers producing private-label versions
• Brand or legacy-label suppliers maintaining residual demand
• International manufacturers serving non-U.S. markets
• Specialty distributors supplying gastroenterology and long-term-care channels

A definitive company-by-company competitive map requires a current FDA Drugs@FDA and Orange Book review. The strategic point is that competition is likely to be fragmented, with supply reliability carrying more weight than patent differentiation.

What is the commercial opportunity and revenue exposure?

The opportunity is a mature, niche generic market rather than a high-growth product category. Revenue depends on prescription volume, channel access, price, shortage conditions, and the number of active suppliers.

A manufacturer can improve economics through:

1. Low-cost, high-yield encapsulation.
2. Multi-market use of a common capsule platform.
3. Private-label or contract-manufacturing agreements.
4. Dual sourcing of controlled-substance active ingredients.
5. Reduced product losses from blend segregation and assay failures.
6. Packaging configurations tailored to retail, institutional, and mail-order channels.
7. Reliable availability during competitor supply interruptions.

Revenue exposure is sensitive to market exit. In a small market, the withdrawal of one supplier can temporarily increase price and volume for remaining manufacturers. That effect is usually temporary and should not be treated as durable exclusivity.

How does this product compare with other gastrointestinal generics?

Chlordiazepoxide/clidinium differs from proton-pump inhibitors, H2 antagonists, antispasmodics, and newer irritable-bowel therapies because it combines gastrointestinal activity with a benzodiazepine.

Product category	Patent position	Regulatory burden	Commercial profile
Chlordiazepoxide/clidinium	Mature and largely unprotected	Controlled-substance and ANDA requirements	Niche, price-sensitive
Omeprazole and related PPIs	Mature generic markets	Standard oral-solid requirements	Larger volume, intense competition
Dicyclomine	Mature generic antispasmodic	Standard prescription controls	Broader antispasmodic market
Newer IBS products	Active or recent exclusivity may apply	Higher clinical and commercial burden	Greater growth potential
Benzodiazepine combinations	Controlled-substance oversight	Higher compliance requirements	Narrower channel access

The combination’s differentiation comes from its established clinical identity, not from a modern delivery system or proprietary excipient platform.

What is the outlook for biosimilar risk?

There is no biosimilar risk. Chlordiazepoxide hydrochloride and clidinium bromide are small-molecule active ingredients, not biologics. Competition occurs through generic-drug pathways, not through abbreviated biologics applications or biosimilar interchangeability.

Key Takeaways

• Chlordiazepoxide HCl and clidinium bromide is a legacy immediate-release capsule, commonly dosed at 5 mg/2.5 mg.
• Active-ingredient and original combination exclusivity are expired or commercially inactive.
• A conventional generic capsule is unlikely to face a material patent barrier, subject to current Orange Book review.
• The principal technical challenge is content uniformity for two low-dose active ingredients.
• Lactose-starch systems offer the lowest-cost development path; lactose-free and HPMC capsules offer limited but possible differentiation.
• Stronger formulation patents would require data showing improved stability, uniformity, dissolution, or manufacturing performance.
• Controlled-substance compliance and supply reliability are more important barriers than patent protection.
• The market is commercially attractive mainly for efficient manufacturers, private-label suppliers, and companies able to maintain dependable supply.
• Biosimilar competition is not relevant because both active ingredients are small molecules.

FAQs

Is chlordiazepoxide and clidinium bromide still commercially viable?

Yes, but primarily as a niche generic or contract-manufactured product. Viability depends on manufacturing cost, supplier reliability, and access to retail, institutional, or specialty-pharmacy channels.

Can a company launch a lactose-free version of Librax?

A company can develop a lactose-free capsule, but the formulation must meet applicable ANDA requirements, demonstrate bioequivalence where required, and maintain reference-product-like dissolution and stability.

Is chlordiazepoxide/clidinium a controlled substance?

The chlordiazepoxide component is a Schedule IV benzodiazepine in the United States. Manufacturing, distribution, inventory, and recordkeeping must comply with controlled-substance requirements.

Can an HPMC capsule create patent protection?

An HPMC shell alone is unlikely to create meaningful protection. Patent value would require a novel capsule system with demonstrated technical advantages, such as improved stability, moisture control, or performance under defined storage conditions.

Does the product face biosimilar competition?

No. The product contains small-molecule active ingredients and competes through generic-drug approvals rather than the biosimilar pathway.

References

1. Valeant Pharmaceuticals International. (2010). Librax (chlordiazepoxide hydrochloride and clidinium bromide) capsule prescribing information. U.S. Food and Drug Administration labeling archive.

2. U.S. Food and Drug Administration. (n.d.). Approved drug products with therapeutic equivalence evaluations: Orange Book. https://www.fda.gov/drugs/drug-approvals-and-databases/approved-drug-products-therapeutic-equivalence-evaluations-orange-book

3. U.S. National Library of Medicine. (n.d.). DailyMed: Chlordiazepoxide hydrochloride and clidinium bromide capsule labeling. https://dailymed.nlm.nih.gov/dailymed/