List of Excipients in Branded Drug UNIPHYL

Generic Drugs Containing UNIPHYL

Company	Ingredient	NDC	Excipient
Purdue Pharmaceutical Products LP	theophylline anhydrous	67781-251	CETOSTEARYL ALCOHOL
Purdue Pharmaceutical Products LP	theophylline anhydrous	67781-251	HYDROXYETHYL CELLULOSE
Purdue Pharmaceutical Products LP	theophylline anhydrous	67781-251	MAGNESIUM STEARATE
Purdue Pharmaceutical Products LP	theophylline anhydrous	67781-251	POVIDONE

What are the Most Frequently-Used Excipients in UNIPHYL?

# Of NDCs	Excipient
1	CETOSTEARYL ALCOHOL
1	HYDROXYETHYL CELLULOSE
1	MAGNESIUM STEARATE
1	POVIDONE

Uniphyl Excipient Strategy and Commercial Opportunities for Extended-Release Theophylline

Last updated: August 4, 2026

Uniphyl is an extended-release theophylline product whose commercial value depends on reliable 12- or 24-hour drug release, dose uniformity, and control of theophylline exposure. Its excipient platform is relatively conventional, which limits broad composition-of-matter protection but creates opportunities for differentiated generic, reformulated, and contract-manufacturing products. The strongest opportunities are once-daily modified-release tablets, lower-dose pediatric products, sprinkle or multiparticulate systems, and formulations designed to reduce food effects and pharmacokinetic variability.

What is Uniphyl and how does its formulation work?

Uniphyl contains theophylline anhydrous in extended-release tablet form. The product is indicated for maintenance treatment of asthma and related reversible airflow-obstruction conditions, although inhaled bronchodilators and inhaled corticosteroids have reduced theophylline's role in current treatment algorithms.[1]

The formulation objective is to slow dissolution and maintain therapeutic plasma concentrations over an extended dosing interval. Theophylline has a relatively narrow therapeutic range. Toxicity can include nausea, vomiting, tachycardia, arrhythmia, seizures, and other central nervous system effects. Clearance varies with age, smoking, fever, hepatic disease, heart failure, and interacting medicines.[1]

The Uniphyl label identifies inactive ingredients including lactose monohydrate, hypromellose, magnesium stearate, and povidone. The tablet is therefore consistent with a hydrophilic matrix or polymer-controlled extended-release design rather than a complex drug-device delivery system.[1]

Attribute	Uniphyl profile
Active ingredient	Theophylline anhydrous
Dosage form	Extended-release tablet
Primary release-control excipient	Hypromellose or another hydrophilic polymer system identified in the product label
Diluent	Lactose monohydrate
Binder or processing aid	Povidone
Lubricant	Magnesium stearate
Therapeutic category	Methylxanthine bronchodilator
Key formulation risk	Dose dumping, variable absorption, and concentration-related toxicity
Regulatory pathway for competitors	Abbreviated New Drug Application, subject to FDA bioequivalence requirements
Biologic or biosimilar status	Not applicable

What excipients protect the commercial performance of Uniphyl?

Hypromellose and polymer-controlled release

Hypromellose, also known as hydroxypropyl methylcellulose, is the principal strategic excipient in a conventional extended-release tablet. After ingestion, the polymer hydrates and forms a gel layer. Drug release occurs through a combination of diffusion, polymer relaxation, and matrix erosion.

The grade and viscosity of hypromellose affect:

• Initial hydration rate
• Gel strength
• Tablet erosion
• Release duration
• Sensitivity to agitation
• Sensitivity to food and gastrointestinal fluid composition

A manufacturer seeking a Uniphyl-equivalent product would need to control polymer substitution type, viscosity grade, particle size, concentration, and distribution within the tablet. These attributes can affect dissolution even when the nominal excipient composition is the same.

Hypromellose is widely available from multiple suppliers. It is therefore unlikely to create a durable supply-chain barrier by itself. Commercial differentiation must come from the complete formulation and manufacturing process, including granulation, compression force, tablet porosity, coating, and dissolution specifications.

Lactose monohydrate

Lactose provides bulk and improves tablet manufacturability. It can affect:

• Tablet weight and size
• Powder flow
• Compactability
• Moisture sensitivity
• Content uniformity
• Matrix porosity and drug diffusion

Lactose is a low-cost, globally available excipient. It has little standalone patent value. Its commercial relevance is operational: changing lactose grade or replacing it with microcrystalline cellulose, mannitol, dibasic calcium phosphate, or a co-processed filler may alter hardness, disintegration, and release.

Povidone

Povidone can function as a binder and processing aid. In a matrix tablet, binder selection affects granule strength and the pore structure through which gastrointestinal fluid enters the tablet. Excessive granule density may slow release, while a weak or porous granule may accelerate release and increase the risk of dose dumping.

Povidone also creates a formulation-development variable because molecular-weight grade, concentration, and wet- versus dry-granulation use can change tablet performance. The ingredient is generic and widely sourced, but a reproducible granulation process can be difficult to copy without development work.

Magnesium stearate

Magnesium stearate reduces friction during compression and ejection. Over-lubrication can create a hydrophobic film around particles, slowing wetting and changing dissolution. The material's impact depends on mixing time, shear, particle size, concentration, and the order in which it is added.

For an extended-release theophylline product, lubrication is a critical process parameter rather than a meaningful standalone exclusivity asset. A generic manufacturer may use the same lubricant but still require formulation adjustment to match dissolution and pharmacokinetic performance.

What patents protect Uniphyl?

Uniphyl's principal commercial protection is unlikely to rest on active-ingredient exclusivity. Theophylline is an old small molecule, and the product's extended-release technology uses established excipient classes.

The relevant protection categories are:

Protection category	Likely relevance to Uniphyl
Theophylline composition-of-matter patent	Expired
Original extended-release formulation patent	Likely expired or no longer commercially blocking because of the product's age
Manufacturing-process patent	Possible historical relevance; difficult to assess without a current patent-family review
Method-of-use patent	Limited value because asthma and obstructive-airway indications are established
Orange Book-listed patent	No current blocking patent should be assumed without checking the applicable FDA Orange Book edition
Trademark protection	Potentially relevant to brand identity, not generic product entry
Trade secret protection	Potentially relevant to process parameters, supplier specifications, and in-process controls

The FDA Orange Book identifies patents and regulatory exclusivities associated with approved drug products. A generic applicant must assess the current listing status for the relevant Uniphyl NDA and any reference-listed drug designation before filing.[2] The product's age makes a live patent barrier less likely than bioequivalence and commercial-scale manufacturing barriers.

When does Uniphyl lose exclusivity?

Uniphyl's small-molecule active ingredient is long past original market exclusivity. The principal commercial question is not the expiration of basic theophylline rights but whether a current manufacturer has enforceable formulation, process, trademark, or contractual rights.

FDA approval of a theophylline extended-release generic generally does not require a new chemical entity exclusivity period. A generic applicant may rely on the reference product through an ANDA if it can demonstrate pharmaceutical equivalence and bioequivalence under the applicable FDA requirements.[3]

The commercial timeline is therefore driven by:

1. Reference-product identification.
2. Availability of the reference product for comparative studies.
3. Formulation development.
4. In vitro dissolution matching.
5. Fed and fasted pharmacokinetic studies.
6. FDA review and manufacturing inspection.
7. State substitution laws and payer contracting.

What FDA regulatory requirements apply to a Uniphyl generic?

A generic extended-release theophylline product must address more than immediate-release tablet equivalence. The FDA may evaluate multiple dissolution conditions and pharmacokinetic profiles to detect early release, delayed release, or food-related differences.

Key development considerations include:

• Single-dose pharmacokinetic comparison under fasting conditions.
• Fed-condition evaluation when required by the product-specific guidance.
• Assessment of peak concentration, total exposure, and time to peak concentration.
• Dissolution testing across multiple pH conditions.
• Demonstration that the product does not release theophylline excessively under rapid agitation.
• Stability under long-term and accelerated conditions.
• Control of tablet hardness, friability, assay, content uniformity, and microbial quality.

Theophylline's therapeutic window makes exposure matching commercially important. A product can satisfy an average bioequivalence criterion while still generating clinical concern if it produces a higher peak concentration, more rapid initial release, or greater interpatient variability.

Are there Paragraph IV challenges to Uniphyl?

A Paragraph IV challenge is possible when an ANDA applicant certifies that a listed patent is invalid, unenforceable, or will not be infringed. For an old extended-release product, the likelihood of a current Paragraph IV dispute is generally lower than for a recently approved drug because core patents may have expired.

The practical litigation questions are:

• Whether the Orange Book lists any unexpired patent.
• Whether the patent claims a specific matrix composition or release profile.
• Whether the reference product has a currently active NDA and market presence.
• Whether the applicant can design around the claimed excipient ratios.
• Whether the patent holder can establish infringement through dissolution behavior or manufacturing evidence.

A formulation patent covering a particular hypromellose grade, polymer ratio, tablet architecture, or release profile could create a litigation issue even after chemical exclusivity has ended. The enforceability and commercial significance would depend on the patent's remaining term and claim scope.

No biosimilar challenge applies because Uniphyl is a small-molecule drug, not a biologic. Competitive products would enter through the ANDA pathway or, for materially different formulations or indications, a 505(b)(2) application.

What formulation opportunities exist beyond the current Uniphyl tablet?

Once-daily modified-release tablets

The most direct opportunity is a robust once-daily tablet with tighter control of early release and overnight exposure. The product could use:

• Higher-viscosity hypromellose
• A polymer blend
• Coated matrix granules
• Tablet-in-tablet architecture
• Multiparticulate pellets compressed into a tablet

The commercial objective is consistent exposure with less sensitivity to meal timing and gastrointestinal transit.

Sprinkle or capsule-based multiparticulates

Multiparticulate theophylline systems can improve dose flexibility and permit administration to patients who have difficulty swallowing tablets. Pellets may be filled into capsules or packaged for sprinkling onto soft food.

This format creates new development requirements, including:

• Pellet size distribution
• Coating uniformity
• Mechanical resistance during handling
• Stability after opening
• Food compatibility
• Dose uniformity after sprinkling

A sprinkle product may qualify for a 505(b)(2) strategy if it differs materially from the reference product and relies in part on published literature or existing FDA findings.

Pediatric and lower-strength products

Theophylline use in children is constrained by variable clearance and toxicity risk. Lower-strength extended-release products could support dose titration and reduce tablet-splitting requirements. A successful product would need precise content uniformity at low drug loads and clear dosing instructions.

Potential formats include:

• 100 mg and 200 mg tablets
• Mini-tablets
• Multiparticulate capsules
• Oral granules with controlled-release coating

A lower-dose product may expand prescriber and caregiver usability, but the market is limited by competition from inhaled therapies.

Reduced food-effect formulations

Food can alter the absorption rate and, for some extended-release theophylline products, total exposure. A formulation designed to minimize fed-versus-fasted differences could be commercially differentiated if supported by comparative pharmacokinetic data.

This opportunity requires a robust clinical and regulatory package. An in vitro claim alone is unlikely to support a meaningful market-positioning advantage.

How strong is the Uniphyl patent estate?

The patent estate is likely weak as a barrier to generic entry but potentially useful as a starting point for formulation improvement. The product's age, established active ingredient, conventional excipients, and broad generic availability reduce the probability that the original formulation alone supports meaningful current exclusivity.

The more defensible intellectual-property positions would likely involve:

• A defined polymer architecture
• A specific dissolution profile linked to pharmacokinetic performance
• A low-variability multiparticulate system
• A manufacturing process that controls matrix porosity
• A formulation that reduces food effect
• A pediatric delivery format
• A combination of excipient grade, process parameters, and release specifications

Process patents may be more difficult to enforce than composition claims because infringement evidence may require discovery of manufacturing records. Trade secrets can protect process controls, but they do not prevent independent development.

Which companies are challenging Uniphyl?

The competitive field is primarily made up of generic manufacturers and suppliers of extended-release theophylline products. Relevant competitors may include manufacturers offering generic theophylline extended-release tablets under their own labels or through authorized distributors.

The main competitive dimensions are:

Competitive factor	Commercial effect
Product availability	Shortages can create substitution opportunities
Strength range	More strengths improve prescribing and pharmacy substitution
FDA-rated therapeutic equivalence	Supports automatic substitution where permitted
Wholesale acquisition cost	Drives payer and pharmacy selection
Manufacturing reliability	Important for a mature, low-margin product
Formulation robustness	Reduces recalls and clinical complaints
Packaging	Unit-dose or moisture-protective packaging can support institutional sales
Pediatric usability	Creates a niche outside standard adult tablets

Because theophylline is a mature market, price and supply reliability are likely to matter more than brand-based differentiation.

What licensing deals could support a Uniphyl opportunity?

Licensing opportunities would most plausibly involve formulation technology, regional rights, or manufacturing capacity rather than the underlying active ingredient.

Potential transaction structures include:

• Licensing a controlled-release polymer platform.
• Acquiring regional rights to an approved generic.
• Contract-manufacturing agreements for low-volume extended-release tablets.
• Co-development of pediatric multiparticulates.
• In-licensing a 505(b)(2) formulation with improved administration.
• Acquiring an abandoned or under-marketed ANDA.

A licensee should evaluate FDA approval status, product-transfer history, technology-transfer documentation, dissolution comparability, manufacturing-site qualification, supply obligations, and any trademark restrictions. The commercial value of a Uniphyl-related license is likely to depend on reliable supply and a differentiated dosage form rather than patent exclusivity.

What generic entry risks exist for Uniphyl?

Generic entry risk is high if the reference product remains commercially available and its regulatory file supports an ANDA pathway. The main risks to an incumbent are:

• Price erosion from therapeutically equivalent tablets.
• Pharmacy substitution.
• Product fragmentation across generic suppliers.
• Loss of formulary preference.
• Regulatory scrutiny after dissolution or stability failures.
• Supply-chain substitution by lower-cost manufacturers.
• Declining clinical use as inhaled products remain preferred.

For a new entrant, the principal risks are different:

• Difficulty obtaining reference product for studies.
• Weak market demand.
• Limited reimbursement differentiation.
• Complex extended-release bioequivalence.
• Low annual volume relative to development and validation costs.
• Manufacturing competition from established generic suppliers.

What is the commercial opportunity for Uniphyl excipient innovation?

The strongest commercial opportunity is a lower-variability extended-release formulation that can demonstrate practical advantages over conventional tablets. The product should target a defined unmet need rather than reproduce the existing tablet at lower cost.

Potential value propositions include:

1. More predictable release across fed and fasted conditions.
2. Lower peak-related adverse effects.
3. Flexible dosing for patients who cannot swallow standard tablets.
4. Pediatric dose titration.
5. Reduced tablet burden through once-daily administration.
6. Improved stability in hot and humid distribution environments.
7. Consistent supply for institutional and international markets.

The market is unlikely to support expensive clinical development for a simple reformulation without a clear regulatory or commercial advantage. A conventional generic can compete on cost, but an improved formulation must justify higher development, manufacturing, and regulatory expenses through differentiated access or pricing.

What geographic markets offer the best opportunity?

The opportunity is strongest in markets where:

• Theophylline remains clinically used.
• Inhaled alternatives are less accessible or more expensive.
• Generic substitution is established.
• Local manufacturing capacity is limited.
• Extended-release oral products are included in public formularies.

The United States offers a defined FDA pathway but a mature, price-sensitive market. Emerging markets may offer greater clinical demand but require country-specific registration, local bioequivalence rules, excipient documentation, serialization, and distribution controls. A regional strategy should separate regulated-market approval from commercial supply economics.

Key Takeaways

• Uniphyl is an extended-release theophylline tablet built around conventional excipients, including hypromellose, lactose monohydrate, povidone, and magnesium stearate.[1]
• Theophylline composition-of-matter protection is expired, and the principal barrier to competition is likely formulation performance rather than active-ingredient patent protection.
• A generic applicant must control extended-release dissolution, fed and fasted pharmacokinetics, dose dumping risk, and manufacturing variability.
• The most attractive formulation opportunities are multiparticulate, pediatric, sprinkle, lower-dose, and reduced-food-effect products.
• No biosimilar pathway applies. Generic competitors would generally use an ANDA, while materially differentiated products may use a 505(b)(2) pathway.
• Paragraph IV risk depends on whether any unexpired Uniphyl-related patent remains listed in the current Orange Book.
• Commercial returns are likely to come from supply reliability, lower manufacturing cost, dosage-form differentiation, or regional access rather than broad patent exclusivity.
• Excipient selection has limited standalone patent value. The defensible asset is the integrated combination of excipient grades, polymer architecture, process controls, dissolution profile, and pharmacokinetic performance.

FAQs about Uniphyl excipient and market strategy

Can hypromellose alone support a new Uniphyl patent?

Usually not. Hypromellose is a well-established extended-release excipient. Patent value would require a specific composition, release profile, process, or clinical performance that is non-obvious and adequately supported by data.

Is a theophylline extended-release product eligible for automatic pharmacy substitution?

Potentially, if the FDA assigns the product an appropriate therapeutic-equivalence rating and state law permits substitution. The specific rating must be verified in the current Orange Book.

Would a Uniphyl sprinkle formulation require a new clinical trial?

Not necessarily. The regulatory requirement depends on the formulation's differences from the reference product, the proposed labeling, the legal basis of the application, and the FDA's bioequivalence expectations. A 505(b)(2) product may require clinical or pharmacokinetic studies beyond a conventional ANDA.

Which excipient is most important for Uniphyl release control?

The release-controlling polymer, typically hypromellose in a conventional matrix design, has the largest direct effect on release duration. Tablet porosity, compression, granulation, and lubrication can materially modify its performance.

Is Uniphyl an attractive target for a pharmaceutical licensing deal?

It may be attractive for a low-cost generic acquisition, regional supply agreement, or differentiated pediatric or multiparticulate product. Its value is less likely to come from a strong remaining patent estate and more likely to come from approved regulatory status, manufacturing reliability, and market access.

References

1. U.S. Food and Drug Administration. (n.d.). Uniphyl- theophylline tablet, extended release prescribing information. DailyMed.
2. U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations, 44th edition.
3. U.S. Food and Drug Administration. (2023). Abbreviated new drug application submissions: Generic drug user fee amendments. FDA.