List of Excipients in Branded Drug GUAIFENESIN AND PSEUDOEPHEDRINE HCL

Generic Drugs Containing GUAIFENESIN AND PSEUDOEPHEDRINE HCL

Company	Ingredient	NDC	Excipient
WALGREEN CO	guaifenesin and pseudoephedrine hcl	0363-0134	HYPROMELLOSE 2208
WALGREEN CO	guaifenesin and pseudoephedrine hcl	0363-0134	MAGNESIUM STEARATE
WALGREEN CO	guaifenesin and pseudoephedrine hcl	0363-0134	MICROCRYSTALLINE CELLULOSE 101
WALGREEN CO	guaifenesin and pseudoephedrine hcl	0363-0134	MICROCRYSTALLINE CELLULOSE 102
WALGREEN CO	guaifenesin and pseudoephedrine hcl	0363-0134	POVIDONE K25

What are the Most Frequently-Used Excipients in GUAIFENESIN AND PSEUDOEPHEDRINE HCL?

# Of NDCs	Excipient
5	CARBOMER HOMOPOLYMER TYPE B
9	CELLULOSE, MICROCRYSTALLINE
7	FD&C YELLOW NO. 6
7	HYPROMELLOSE 2208
5	HYPROMELLOSE 2910

Excipient Strategy and Commercial Opportunities for Guaifenesin and Pseudoephedrine HCl

Last updated: August 31, 2026

Guaifenesin and pseudoephedrine HCl combination products are mature U.S. over-the-counter medicines with limited active-ingredient patent risk and substantial formulation, compliance, and supply-chain opportunities. The strongest commercial positions are likely to come from extended-release performance, tablet robustness, moisture control, taste masking, packaging, and reliable pseudoephedrine-channel compliance rather than new chemical-entity exclusivity.

What is the FDA regulatory status of guaifenesin and pseudoephedrine HCl?

Guaifenesin is an OTC expectorant. Pseudoephedrine HCl is an OTC nasal decongestant subject to federal sales controls because of its potential diversion for illicit methamphetamine production.

Component	Function	U.S. OTC status	Principal formulation issue
Guaifenesin	Expectorant	Permitted under the OTC cough-cold framework	High dose, bitter taste, tablet size, extended release
Pseudoephedrine HCl	Nasal decongestant	Permitted OTC but controlled at retail	Dose uniformity, release control, diversion-resistant packaging
Combination	Cough, mucus, and nasal congestion relief	Marketed under OTC monograph conditions or approved product-specific pathways	Release-rate matching and consumer-use compliance

FDA’s OTC monograph system permits specified active ingredients, indications, doses, dosage forms, and labeling when a product satisfies applicable conditions. The FDA’s current OTC framework is governed by the CARES Act monograph system, including the cough, cold, allergy, bronchodilator, and anti-asthmatic drug monograph framework applicable to these ingredients.[1]

Pseudoephedrine products must comply with the Combat Methamphetamine Epidemic Act of 2005. Retail controls include behind-the-counter placement, purchaser identification, sales logs, daily and monthly quantity limits, and restrictions on self-service access.[2] State requirements can be more restrictive.

What formulations are protected by guaifenesin and pseudoephedrine HCl products?

The principal commercial formulation is an extended-release oral tablet or caplet containing guaifenesin and pseudoephedrine HCl. A representative branded configuration contains 1,200 mg of guaifenesin and 120 mg of pseudoephedrine HCl per extended-release dose, generally administered every 12 hours. Lower-strength configurations also exist.

The formulation objective is difficult because the ingredients have different dose burdens and pharmacokinetic requirements:

• Guaifenesin requires a relatively high mass per dose.
• Pseudoephedrine HCl is potent at a much lower mass.
• Guaifenesin can create large, friable tablets if the formulation relies heavily on direct compression.
• Pseudoephedrine must release predictably without creating an unnecessarily high early exposure.
• The combination must remain stable under humidity, heat, and extended shelf storage.
• The dosage form must resist crushing and dose dumping without becoming excessively difficult to swallow.

Historically, extended-release guaifenesin products have relied on matrix systems, compressed multilayer structures, hydrophilic polymers, coated particles, or combinations of these approaches. A new applicant must demonstrate that the release profile, assay, content uniformity, dissolution, stability, and labeling meet the applicable regulatory standard.

Which excipients are most valuable for this combination?

The most commercially relevant excipient strategy uses a controlled-release matrix for guaifenesin, a low-dose pseudoephedrine delivery phase, and processing aids that improve tablet manufacture.

Controlled-release polymers

Hydrophilic polymers are central to extended-release development. Candidate materials include:

• Hypromellose, including selected viscosity grades
• Hydroxypropyl cellulose
• Polyethylene oxide
• Carbomers
• Ethylcellulose in coated or matrix applications
• Methacrylate copolymers for pH-dependent or membrane-controlled release

Hypromellose is commercially attractive because it has broad pharmaceutical use, established regulatory acceptance, and scalable processing characteristics. Higher-viscosity grades can reduce drug release but may increase tablet swelling, compression force, and dissolution variability.

Polyethylene oxide can provide strong gel formation but may create manufacturing and stability challenges. Ethylcellulose can improve membrane control but typically requires a coating process and more complex process validation.

Binders and dry-granulation aids

Guaifenesin’s high loading can produce poor flow and weak compacts. Useful binders and granulation aids include:

• Povidone
• Copovidone
• Microcrystalline cellulose
• Pregelatinized starch
• Hydroxypropyl cellulose
• Silicified microcrystalline cellulose

Dry granulation can reduce water exposure and simplify scale-up. Wet granulation may improve content uniformity and tablet strength but introduces moisture and drying controls that can affect release performance.

Fillers and compression supports

Microcrystalline cellulose is frequently useful for improving compactibility and reducing tablet friability. Lactose, mannitol, dibasic calcium phosphate, and starch-based materials can support density and mouthfeel, but each affects dissolution, moisture sensitivity, and tablet size.

Dibasic calcium phosphate can provide good flow and low hygroscopicity, although its density and brittle fracture behavior may require optimization. Mannitol may improve sensory properties but can increase cost and may alter tablet porosity.

Lubricants and glidants

Magnesium stearate remains a standard lubricant, but excessive use or overmixing can reduce tablet hardness and slow dissolution. Alternatives such as sodium stearyl fumarate may be useful where faster lubrication or lower hydrophobicity is desired.

Colloidal silicon dioxide can improve flow and reduce segregation, which is important when a low-dose pseudoephedrine phase is combined with a high-dose guaifenesin phase.

Taste-masking excipients

Taste masking is less important for intact tablets than for liquid or chewable products, but it becomes commercially important in pediatric and on-the-go formats. Options include:

• Ion-exchange resins
• Polymer-coated drug particles
• Lipid-based barriers
• Flavors and sweeteners
• Cyclodextrin complexes in selected applications

Pseudoephedrine and guaifenesin can produce an unpleasant oral profile if a tablet is chewed, split, or partially disintegrates in the mouth. Any taste-masking approach must preserve the intended release profile and avoid increasing the risk of dose dumping.

How should an extended-release excipient platform be designed?

A practical development strategy is to separate the release functions rather than force both active ingredients into a single undifferentiated matrix.

Development objective	Preferred formulation approach	Main risk
12-hour guaifenesin release	Hydrophilic polymer matrix or coated multiparticulates	Incomplete release or excessive tablet size
Controlled pseudoephedrine release	Separate matrix phase, coated granules, or bilayer architecture	Early burst release
High drug loading	Dry granulation with compactibility enhancer	Weight variation and friability
Moisture protection	Film coat, low-moisture excipients, high-barrier packaging	Dissolution drift during storage
Abuse-resistance support	Mechanical-strengthening design and packaging controls	Added manufacturing cost and swallowing burden
Small, swallowable tablet	Bilayer or multiparticulate technology	More complex equipment and validation

A bilayer tablet can provide a commercially differentiated release profile, but it increases tooling, compression, layer adhesion, and manufacturing-validation requirements. A single-layer matrix is simpler and may be more economical, although it can be less flexible when the two actives require different release rates.

Multiparticulate systems can improve dose distribution and reduce the consequences of localized tablet defects. Their disadvantages include higher processing complexity, coating variability, and greater dependence on specialized equipment.

What manufacturing and intellectual-property barriers exist?

For this combination, the principal barriers are formulation know-how and process control rather than basic active-ingredient composition.

Critical manufacturing variables include:

• Granule particle-size distribution
• Blend uniformity for the low-dose pseudoephedrine component
• Compression force and dwell time
• Polymer hydration and gel formation
• Film-coat weight gain
• Tablet porosity
• Residual moisture
• Packaging water-vapor transmission
• Dissolution performance after accelerated stability storage

A commercially meaningful formulation patent would need to claim a defensible combination of composition, release profile, process parameters, or product performance. Broad claims covering guaifenesin and pseudoephedrine together are likely to face prior-art challenges because the ingredients and combination category are mature.

Potentially protectable subject matter includes:

• A defined polymer ratio producing a specified 12-hour dissolution profile
• A bilayer arrangement that separates the active ingredients
• A low-moisture manufacturing process
• A coating architecture that limits pseudoephedrine burst release
• A tablet with specified hardness, friability, and dissolution characteristics
• A packaging and dosage-form system addressing retail-control or diversion concerns

Trade-secret protection can be more valuable than patent protection where the advantage comes from granulation endpoint, compression settings, coating conditions, or excipient grade selection.

What is the Orange Book status of guaifenesin and pseudoephedrine HCl?

Standard OTC guaifenesin and pseudoephedrine HCl products generally do not have the same Orange Book patent-listing structure as prescription products approved through an NDA. The FDA Orange Book primarily identifies approved prescription drug products and certain approved nonprescription products with listed patents and exclusivity.[3]

As a result:

• A conventional OTC monograph product normally does not generate a standard Orange Book patent dispute.
• Paragraph IV litigation is not the ordinary pathway for challenging an OTC monograph formulation.
• A product approved under an NDA or another application-specific pathway could have a different patent and exclusivity profile.
• Patent risk should be evaluated through U.S. Patent and Trademark Office records, commercial-label review, litigation databases, and any application-specific FDA listing.

When does guaifenesin and pseudoephedrine HCl lose exclusivity?

The active ingredients have long been off-patent. There is no meaningful new-molecule exclusivity remaining for either guaifenesin or pseudoephedrine HCl.

Exclusivity category	Current assessment
New chemical entity exclusivity	None
Standard prescription exclusivity	Not applicable to conventional OTC products
Biosimilar exclusivity	Not applicable
Active-ingredient patent protection	Expired or unavailable as a current barrier
Formulation patent risk	Product-specific and generally limited to defined technologies
Trademark protection	Potentially material for established brands
OTC monograph protection	Regulatory compliance, not market exclusivity
Retail-channel protection	Significant operational barrier because of pseudoephedrine controls

A generic or private-label manufacturer can compete without waiting for a branded small-molecule patent term to expire if it satisfies the applicable OTC regulatory requirements and does not infringe enforceable formulation, process, trademark, or packaging rights.

Which companies are challenging the branded market?

The market is supplied by branded manufacturers, store brands, contract manufacturers, and generic OTC companies. The major competitive groups include:

• Reckitt and other owners or marketers of branded cough-cold products
• Perrigo
• Haleon
• Kenvue
• Teva and other generic manufacturers
• Retail pharmacy private-label suppliers
• Contract development and manufacturing organizations

The principal commercial benchmark is the Mucinex D product family, while store-brand equivalents compete on price and retailer placement. Competition is less dependent on active-ingredient differentiation than on:

• Retail availability
• Brand recognition
• Twelve-hour dosing
• Tablet size and swallowability
• Packaging convenience
• Wholesale reliability
• Retailer margin
• Product-line breadth

What generic entry risks exist for guaifenesin and pseudoephedrine HCl?

Generic entry risk is high for the active ingredients and moderate for a differentiated extended-release product.

High-risk areas for the branded product

• Low active-ingredient manufacturing cost
• Mature excipient technology
• Broad availability of direct-compression and granulation equipment
• Lack of new-chemical-entity exclusivity
• Multiple established OTC manufacturers
• Limited clinical differentiation

Moderate-risk areas

• Reproducing the branded dissolution profile
• Managing high guaifenesin loading
• Maintaining tablet integrity through distribution
• Achieving acceptable pseudoephedrine content uniformity
• Meeting stability requirements across climate zones
• Preserving a similar consumer experience without copying protected trade dress

The generic entrant’s most significant non-patent barrier is compliance with pseudoephedrine sales controls. Inventory must be allocated to compliant retailers, and packaging, customer verification, transaction logging, and distribution procedures must support federal and state requirements.

What patent litigation and Paragraph IV issues affect the market?

No ordinary Paragraph IV litigation pathway is expected for a conventional OTC monograph combination. Litigation risk is more likely to arise from:

• Formulation or process patents asserted in district court
• Trademark and trade-dress disputes
• False advertising claims involving release duration or symptom relief
• Product liability claims
• Contract disputes with manufacturers or distributors
• Regulatory challenges concerning labeling or active-ingredient conditions

Historic extended-release guaifenesin patents may appear in older patent landscapes, but their commercial relevance depends on expiration, terminal disclaimers, claim scope, continuations, and whether the claims cover the proposed product. A historical patent number should not be treated as a current market barrier without a live-status and claim-scope review.

What licensing opportunities exist for excipient suppliers and manufacturers?

Licensing opportunities are strongest in formulation platforms rather than in the active ingredients.

Potential targets include:

1. Extended-release polymer platforms. Suppliers can license proprietary polymer grades, coating systems, or release-control processes to OTC manufacturers.

2. High-load tablet technologies. A platform that reduces tablet mass while maintaining mechanical strength can improve swallowability and manufacturing economics.

3. Low-dose blend-uniformity systems. Specialized granulation and blending processes can reduce pseudoephedrine content-uniformity risk.

4. Moisture-control systems. Excipient and packaging combinations that preserve dissolution through shelf life can support premium private-label products.

5. Pediatric and liquid formats. Taste-masking systems may enable new dosage forms, subject to age-specific safety and regulatory requirements.

6. Diversion-control packaging. Unit-dose, blister, and traceable packaging can support retail compliance and reduce operational losses, although packaging alone does not eliminate statutory sales obligations.

How does this combination compare with competing cough-cold products?

Product category	Main advantage	Excipient opportunity	Commercial risk
Guaifenesin alone	Expectorant positioning	Extended release, smaller tablet	Limited symptom coverage
Pseudoephedrine alone	Decongestant positioning	Immediate or extended release	Retail restrictions
Guaifenesin plus pseudoephedrine	Combined mucus and congestion relief	Release-rate separation and compact dosage form	Larger tablet and higher compliance burden
Phenylephrine combinations	Broad retail availability	Taste masking and immediate release	Lower perceived efficacy in some market assessments
Multi-symptom products	Broad indication coverage	Complex compatibility and release design	More side effects and label complexity

The guaifenesin-pseudoephedrine combination has a clear product-positioning advantage for consumers seeking both mucus relief and nasal decongestion. Its weakness is operational: pseudoephedrine restrictions narrow retail access and increase compliance cost.

What commercial opportunities have the strongest return potential?

The strongest opportunities are likely to be:

• A smaller extended-release caplet with equivalent performance
• A robust generic or private-label product with reliable year-round supply
• A premium blister-pack configuration for controlled retail distribution
• A lower-cost dry-granulation process
• A moisture-resistant formulation with extended shelf stability
• A pediatric or liquid presentation with effective taste masking, if regulatory requirements support it
• A contract manufacturing platform that can produce multiple strengths using the same excipient architecture

A new excipient system should be assessed against four commercial tests: lower cost per dose, improved dissolution consistency, reduced tablet burden, or meaningful packaging and supply-chain differentiation. Without one of these advantages, the formulation is likely to compete primarily on price.

Key Takeaways

• Guaifenesin and pseudoephedrine HCl are mature OTC active ingredients with no meaningful new-molecule exclusivity.
• The commercial focus is extended-release formulation performance, not active-ingredient patent protection.
• Hypromellose, microcrystalline cellulose, povidone or copovidone, glidants, lubricants, and moisture-control systems are likely core excipient categories.
• Bilayer and multiparticulate systems can improve release-rate separation but increase manufacturing complexity.
• Orange Book and Paragraph IV risks are generally limited for conventional OTC monograph products.
• Pseudoephedrine retail controls are a material operational barrier for generic and private-label entry.
• The most attractive licensing opportunities involve high-load compression, release control, taste masking, moisture protection, and compliant packaging.
• The strongest competitive products will combine reliable supply, compact tablets, stable dissolution, and retailer-friendly pseudoephedrine controls.

FAQs

Can guaifenesin and pseudoephedrine HCl be formulated as a liquid?

Yes, but the formulation requires careful control of solubility, taste, chemical stability, preservative compatibility, and dose uniformity. The high guaifenesin dose can make a clear liquid impractical, increasing the relevance of suspensions, suspending agents, and taste-masking systems.

Is pseudoephedrine HCl compatible with common controlled-release polymers?

Generally, yes. Compatibility must be confirmed through assay, impurity, dissolution, and stability studies because polymer grade, ionic interactions, moisture, and compression conditions can alter release behavior.

Can a company patent a new guaifenesin-pseudoephedrine tablet?

Potentially, if the product has novel and non-obvious composition, structure, process, or performance characteristics. A broad claim to the ingredient combination alone is unlikely to provide a strong current position.

Are biosimilars relevant to guaifenesin and pseudoephedrine HCl?

No. Both are small-molecule active ingredients. Competition occurs through OTC monograph compliance, application-specific approval where applicable, generic manufacturing, trademarks, and retail distribution rather than the biosimilar pathway.

Does behind-the-counter status create market exclusivity for a pseudoephedrine product?

No. It creates compliance and distribution obligations, not exclusivity. Multiple manufacturers can market compliant pseudoephedrine products, subject to federal, state, retailer, and supply-chain requirements.

References

1. U.S. Food and Drug Administration. (2023). Over-the-counter monograph drugs. https://www.fda.gov/drugs/over-counter-otc-nonprescription-drugs/otc-monograph-reform

2. U.S. Drug Enforcement Administration. (n.d.). Pseudoephedrine and ephedrine regulations. https://www.dea.gov

3. U.S. Food and Drug Administration. (2024). 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