List of Excipients in Branded Drug RUGBY MUCUS RELIEF ER

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Generic Drugs Containing RUGBY MUCUS RELIEF ER

Company	Ingredient	NDC	Excipient
Rugby Laboratories	guaifenesin	0536-1451	CARBOMER HOMOPOLYMER TYPE B
Rugby Laboratories	guaifenesin	0536-1451	CELLULOSE, MICROCRYSTALLINE
Rugby Laboratories	guaifenesin	0536-1451	COPOVIDONE K25-31
Rugby Laboratories	guaifenesin	0536-1451	FD&C BLUE NO. 1 ALUMINUM LAKE
Rugby Laboratories	guaifenesin	0536-1451	HYPROMELLOSE
Rugby Laboratories	guaifenesin	0536-1451	MAGNESIUM STEARATE
Rugby Laboratories	guaifenesin	0536-1451	SILICON DIOXIDE

What are the Most Frequently-Used Excipients in RUGBY MUCUS RELIEF ER?

# Of NDCs	Excipient
2	CARBOMER HOMOPOLYMER TYPE B
2	CELLULOSE, MICROCRYSTALLINE
1	COPOVIDONE K25-31
2	FD&C BLUE NO. 1 ALUMINUM LAKE
2	HYPROMELLOSE
2	MAGNESIUM STEARATE
1	SILICON DIOXIDE

Rugby Mucus Relief ER Excipient Strategy and Commercial Opportunities

Last updated: September 29, 2026

Rugby Mucus Relief ER is an over-the-counter extended-release guaifenesin product positioned against Mucinex 600 mg and other private-label expectorants. Its commercial value depends less on active-ingredient exclusivity than on reliable 12-hour release, tablet swallowability, low manufacturing cost, packaging differentiation, and retailer distribution.

The principal excipient opportunity is to improve extended-release performance without adding formulation complexity. Suitable strategies include hydrophilic matrix optimization, smaller tablets, stronger film coating, reduced friability, and packaging designed for moisture protection. Guaifenesin is an established OTC monograph ingredient, so an excipient change generally requires regulatory and bio-performance support rather than a new drug approval, provided the product remains within the applicable monograph conditions.

What is Rugby Mucus Relief ER?

Rugby Mucus Relief ER is a store-brand extended-release expectorant containing guaifenesin. Rugby products are associated with private-label pharmaceutical distribution and institutional, retail, and healthcare channels.

Attribute	Product assessment
Product	Rugby Mucus Relief ER
Active ingredient	Guaifenesin
Dosage form	Extended-release tablet
Primary indication	Relief of chest congestion by loosening phlegm and thinning bronchial secretions
Regulatory category	OTC drug
Likely dosage strength	600 mg extended-release tablet
Administration	Typically one tablet every 12 hours, subject to the marketed label
Reference competitor	Mucinex Extended-Release Tablets
Main commercial channel	Private-label retail, pharmacy, institutional and value channels
Patent dependence	Low
Primary competitive variables	Cost, release consistency, tablet size, packaging, supply reliability and retailer margin

The marketed package and applicable National Drug Code should control any final assessment of strength, excipient composition and labeling. Extended-release guaifenesin products are commonly sold in 600 mg and 1,200 mg strengths.

What excipients are used in extended-release guaifenesin tablets?

Extended-release guaifenesin tablets generally use a hydrophilic matrix or polymer-controlled release system. Common functional excipient categories include the following:

Excipient category	Typical function	Strategic relevance
Hypromellose	Hydrophilic matrix former	Controls water penetration and drug release
Microcrystalline cellulose	Diluent and compression aid	Supports tablet strength and manufacturability
Povidone	Binder	Improves granule and tablet cohesion
Croscarmellose sodium or sodium starch glycolate	Disintegrant	Can improve matrix breakup if used in controlled quantities
Colloidal silicon dioxide	Glidant	Improves powder flow
Magnesium stearate	Lubricant	Reduces sticking and ejection force
Film-coating polymers	Protection, appearance and swallowability	Supports product differentiation and moisture control
Opacifiers and colorants	Appearance and light protection	Enable private-label identification
Polyols or carbohydrate fillers	Dilution and mouthfeel	Affect tablet size and compressibility

The key technical tension is between maintaining a 12-hour release profile and preventing an overly large, hard-to-swallow tablet. Guaifenesin doses are relatively high for a solid oral product, so excipient selection materially affects tablet dimensions.

How does the extended-release excipient system work?

A hydrophilic matrix typically uses hypromellose or a related polymer. After ingestion, the polymer hydrates and forms a gel layer. Drug release occurs through a combination of diffusion, matrix erosion and gradual penetration of gastrointestinal fluids.

The formulation must control several variables:

1. Polymer viscosity grade.
2. Polymer concentration.
3. Particle-size distribution of guaifenesin.
4. Compression force and tablet porosity.
5. Lubricant concentration.
6. Coating weight and permeability.
7. Manufacturing scale and granulation endpoint.

Higher-viscosity hypromellose grades can reduce the initial release rate but may increase tablet size or cause incomplete release. Lower-viscosity grades may improve processability but create a faster release profile. A mixed-polymer matrix can provide greater control, but it increases qualification and scale-up requirements.

The excipient strategy should prioritize release robustness across normal manufacturing variation rather than optimize only a single dissolution curve.

What excipient strategies could improve Rugby Mucus Relief ER?

1. Optimize the hypromellose matrix

The most direct strategy is to screen hypromellose grades and concentrations to identify a matrix that delivers consistent release over 12 hours. Critical development variables include:

• Polymer viscosity.
• Polymer particle size.
• Matrix-former loading.
• Compression force.
• Tablet porosity.
• Granulation method.

A robust matrix should limit dose dumping under abnormal agitation and preserve release behavior after storage.

2. Reduce tablet size

Guaifenesin ER tablets can be large because of the 600 mg drug load and the additional polymer needed for controlled release. Commercial improvements may come from:

• Higher drug-load formulations.
• Roller compaction instead of wet granulation.
• More efficient high-density fillers.
• Lower-volume binders.
• Optimized particle-size engineering.
• Bilayer or multilayer compression.

A smaller tablet has direct consumer value because swallowing difficulty can reduce adherence and repeat purchase.

3. Improve tablet strength without slowing dissolution

High compression force can increase tablet hardness and reduce friability, but excessive compression can reduce porosity and delay hydration. Magnesium stearate over-lubrication can also slow wetting and create release variability.

An optimized formulation can combine:

• Low-level lubricant addition.
• Controlled blending time.
• High-functionality microcrystalline cellulose.
• Granulation to improve density.
• Compression-force design space studies.

The objective is a tablet that survives coating, packaging, shipping and consumer handling while meeting the release specification.

4. Use a functional film coating

A film coating can improve swallowing, appearance and moisture protection. It can also support retailer differentiation through color and imprinting.

The coating should not materially interfere with the intended release profile unless it is deliberately designed as part of the release system. A moisture-barrier coating may improve stability, particularly where the matrix contains hygroscopic materials or where the product is distributed in high-humidity environments.

5. Evaluate direct compression

Direct compression can reduce manufacturing steps and lower cost. Its feasibility depends on powder flow, compressibility, segregation risk and active-ingredient loading.

A direct-compression platform is commercially attractive if it can maintain:

• Uniform guaifenesin content.
• Acceptable tablet weight variation.
• Low capping and sticking.
• Consistent dissolution.
• Adequate mechanical strength.

If the active ingredient has poor flow or compressibility, roller compaction may offer a better compromise than conventional wet granulation.

What is the FDA regulatory status of extended-release guaifenesin?

Guaifenesin is regulated as an OTC expectorant under the FDA’s OTC monograph framework. The applicable regulatory requirements are set out in 21 C.F.R. part 341 and related FDA OTC monograph materials.

For an extended-release product, the formulation must comply with the applicable active-ingredient, dosage, labeling and quality requirements. The product does not ordinarily require a conventional new drug application when it is marketed in accordance with the monograph and other applicable requirements.

The manufacturer remains responsible for demonstrating:

• Identity, strength, quality and purity.
• Content uniformity.
• Stability through labeled shelf life.
• Appropriate dissolution or release performance.
• Manufacturing process control.
• Adequate labeling.
• Compliance with current good manufacturing practice.

A material excipient change may require comparative dissolution, stability testing, process validation and, depending on the change, additional regulatory assessment. The principal risk is usually not patent exposure but failure to maintain monograph compliance and product quality.

What patents protect Rugby Mucus Relief ER?

Rugby Mucus Relief ER is unlikely to depend on an active-ingredient patent. Guaifenesin has been used in OTC products for decades, and the ingredient itself is not commercially protected by a live U.S. composition-of-matter patent.

The relevant IP categories are more limited:

IP category	Relevance to Rugby Mucus Relief ER
Guaifenesin composition patent	No meaningful current exclusivity expected
Generic extended-release formulation patent	Possible in the industry, but not necessarily applicable to Rugby
Manufacturing process patent	May affect a particular supplier or contract manufacturer
Tablet coating or matrix patent	Could create freedom-to-operate issues if the formulation copies a protected platform
Trademark and trade dress	Relevant to Rugby branding and packaging
Private-label supply agreement	Commercially important but generally confidential

Because the product is an OTC monograph drug, it does not normally have an Orange Book patent-listing profile comparable to an NDA product. It also does not generally face Paragraph IV litigation based solely on a private-label guaifenesin product.

What is the Orange Book and Paragraph IV status?

Rugby Mucus Relief ER is not expected to have a conventional Orange Book exclusivity position because it is an OTC monograph product rather than a prescription NDA product.

The commercial implications are direct:

• No expected Hatch-Waxman patent barrier for guaifenesin itself.
• No conventional Paragraph IV certification associated with a monograph-compliant OTC launch.
• No meaningful five-year new chemical entity exclusivity.
• No standard Orange Book patent-cliff event tied to Rugby’s brand.
• Potential freedom-to-operate issues only at the formulation, process, trademark or packaging level.

A competitor can generally enter with a compliant guaifenesin extended-release product without waiting for Rugby exclusivity to expire. The practical barriers are formulation performance, manufacturing qualification, retailer access and consumer recognition.

When does Rugby Mucus Relief ER lose exclusivity?

Rugby Mucus Relief ER does not have a conventional patent expiration date that determines generic entry. Its commercial protection is based on private-label positioning, distribution agreements, retailer relationships and product execution.

The product can face competition at any time from:

• National-brand guaifenesin products.
• Pharmacy generic products.
• Other retailer private labels.
• Combination cough, cold and mucus products.
• Liquid expectorants.
• Immediate-release guaifenesin tablets.
• 1,200 mg twice-daily extended-release tablets.

This creates a continuous competitive environment rather than a single patent-expiration event.

What commercial opportunities exist for excipient suppliers?

Excipient suppliers can target Rugby-type products through cost reduction, performance enhancement and formulation redevelopment.

Controlled-release polymer systems

Hypromellose suppliers can offer polymer grades designed for predictable hydration, reduced batch variability and improved tablet compactability. A supplier with strong technical support can compete on validated performance rather than price alone.

Co-processed excipients

Co-processed fillers and binders may reduce the number of formulation components and improve direct-compression performance. This can reduce dispensing, blending and quality-control complexity.

Moisture-barrier systems

Coating suppliers can offer aqueous film coatings with improved moisture resistance, low weight gain and fast processing. This is relevant for products distributed through broad retail channels and stored in variable climates.

Lubricant and flow systems

Engineered lubricants and glidant systems may reduce sticking and improve throughput. The commercial benefit is strongest where the formulation has high active loading and narrow compression-process tolerances.

Taste and swallowability improvements

Although the tablet is swallowed intact, coating smoothness, tablet geometry and surface friction affect consumer acceptance. A smoother coating or capsule-shaped tablet can support a premium private-label position without changing the active ingredient.

How does Rugby compare with Mucinex?

Factor	Rugby Mucus Relief ER	Mucinex Extended-Release
Active ingredient	Guaifenesin	Guaifenesin
Regulatory basis	OTC monograph	OTC monograph or applicable FDA pathway
Brand strength	Retailer or private-label dependent	National consumer brand
Price position	Usually value-oriented	Often premium-priced
Patent leverage	Limited	May have historical formulation, trademark or brand assets, but guaifenesin itself is not exclusive
Main advantage	Retail margin and price	Consumer recognition and marketing
Formulation opportunity	Cost-efficient, robust matrix	Premium swallowability, packaging and differentiated release
Entry barrier	Retail access and manufacturing	Brand loyalty and marketing spend

The strongest private-label strategy is not to duplicate the national brand’s marketing. It is to provide equivalent release performance at a lower retail price while improving tablet size, packaging and supply reliability.

What manufacturing and IP barriers exist?

The manufacturing barriers are moderate. The drug load is high, and extended-release performance must remain consistent across scale. Key technical risks include:

• Segregation of guaifenesin from lower-density excipients.
• Tablet capping and lamination.
• Sticking during compression.
• Variable hydration of the polymer matrix.
• Dissolution shifts after coating.
• Moisture-related stability changes.
• Release variability after scale-up.
• Packaging failures in high humidity.

The IP barriers are generally lower than the manufacturing barriers. A competitor should conduct a freedom-to-operate review covering formulation patents, controlled-release matrix patents, process patents, tablet geometry, coating systems, trademarks and package design.

What generic launch scenarios exist?

Low-cost private-label launch

A manufacturer can launch a monograph-compliant guaifenesin ER tablet using a conventional matrix system. The main advantage is price. The risk is limited differentiation and retailer substitution.

Premium private-label launch

A smaller tablet, improved coating, clearer labeling and better packaging can support a higher-margin retailer product. This approach may require more formulation development but can reduce direct price comparison.

Dual-strength portfolio

A 600 mg tablet for standard dosing and a 1,200 mg tablet for twice-daily convenience can broaden shelf coverage. The portfolio can share excipient platforms and manufacturing equipment.

Combination-product expansion

Guaifenesin can be combined with other OTC actives, subject to monograph and labeling requirements. Combination products increase regulatory and formulation complexity, particularly where active ingredients have different release requirements.

Institutional and pharmacy-channel product

A plain-label product with unit-dose packaging, case-level pricing and reliable supply may be attractive to hospitals, long-term-care providers and pharmacy wholesalers.

Key Takeaways

• Rugby Mucus Relief ER is an OTC extended-release guaifenesin product with limited active-ingredient exclusivity.
• The main formulation opportunity is a robust hydrophilic matrix that controls 12-hour release without producing an excessively large tablet.
• Hypromellose, microcrystalline cellulose, binders, lubricants and moisture-barrier coatings are the core excipient levers.
• Tablet size, swallowability, coating quality and packaging are commercially meaningful differentiators.
• The product is not expected to have a conventional Orange Book patent cliff or Paragraph IV challenge.
• Generic and private-label entry is primarily constrained by manufacturing performance, retailer access, supply reliability and consumer positioning.
• Excipient suppliers have the clearest opportunities in controlled-release polymers, co-processed compression systems, moisture-barrier coatings and process-robust lubricant systems.

FAQs

Is Rugby Mucus Relief ER a generic version of Mucinex?

It is a private-label guaifenesin extended-release product competing with Mucinex. It is not necessarily an ANDA-approved generic of a particular Mucinex product because OTC monograph products follow a different regulatory framework.

Does guaifenesin require a prescription?

No. Guaifenesin is widely marketed as an OTC expectorant when the product complies with applicable FDA monograph and labeling requirements.

Can an excipient change create a new patent opportunity?

Yes. A novel controlled-release matrix, manufacturing process, coating system or tablet architecture may support patent protection if it meets applicable novelty, nonobviousness and written-description standards. Routine substitution of one conventional excipient for another is less likely to create strong patent value.

Is a 1,200 mg tablet commercially attractive?

Yes. A 1,200 mg extended-release tablet can provide twice-daily dosing convenience, but it creates greater tablet-size, compression, swallowability and dose-uniformity challenges than a 600 mg product.

What is the strongest commercial differentiator for a private-label guaifenesin ER product?

A combination of lower cost, consistent 12-hour release, smaller tablet dimensions, moisture-protective packaging and dependable supply is likely to be more valuable than a minor change in inactive ingredients.

References

1. Electronic Code of Federal Regulations. (2024). 21 C.F.R. Part 341: Cold, cough, allergy, bronchodilator, and antiasthmatic drug products for over-the-counter human use. https://www.ecfr.gov/current/title-21/chapter-I/subchapter-D/part-341

2. U.S. Food and Drug Administration. (2024). Over-the-counter monograph drugs. https://www.fda.gov/drugs/over-counter-otc-nonprescription-drugs

3. U.S. Food and Drug Administration. (2024). Current good manufacturing practice for finished pharmaceuticals, 21 C.F.R. Part 211. https://www.ecfr.gov/current/title-21/chapter-I/subchapter-C/part-211

4. U.S. National Library of Medicine. (2024). DailyMed: Guaifenesin extended-release tablet labeling. https://dailymed.nlm.nih.gov/dailymed/

5. U.S. Patent and Trademark Office. (2024). Patent Center. https://patentcenter.uspto.gov/