List of Excipients in Branded Drug ULTRAMICROSIZE GRISEOFULVIN

Generic Drugs Containing ULTRAMICROSIZE GRISEOFULVIN

Company	Ingredient	NDC	Excipient
Amneal Pharmaceuticals of New York LLC	ultramicrosize griseofulvin tablets	0115-1724	MAGNESIUM STEARATE
Amneal Pharmaceuticals of New York LLC	ultramicrosize griseofulvin tablets	0115-1724	POLYETHYLENE GLYCOL 3350
Amneal Pharmaceuticals of New York LLC	ultramicrosize griseofulvin tablets	0115-1724	POLYETHYLENE GLYCOL 6000

What are the Most Frequently-Used Excipients in ULTRAMICROSIZE GRISEOFULVIN?

# Of NDCs	Excipient
7	ANHYDROUS LACTOSE
1	CALCIUM STEARATE
1	CELLULOSE, MICROCRYSTALLINE

Last updated: August 16, 2026

Ultramicrosize griseofulvin is an established, off-patent oral antifungal formulation with limited patent protection but meaningful formulation opportunities. The commercial value lies in improving dissolution, dose consistency, pediatric usability, food-effect control, and supply reliability rather than extending exclusivity through traditional compound patents. The main product opportunities are low-cost tablets, pediatric liquids or suspensions, and differentiated lipid, nanocrystal, or taste-masked formulations.

Ultramicrosize Griseofulvin Excipient Strategy and Commercial Opportunities

What is ultramicrosize griseofulvin?

Ultramicrosize griseofulvin is a reduced-particle-size oral form of griseofulvin designed to improve gastrointestinal dissolution and absorption. The active ingredient is a systemic antifungal used primarily for dermatophyte infections, including tinea corporis, tinea cruris, tinea pedis, tinea capitis, and tinea unguium.

The formulation is distinct from conventional microsize griseofulvin. FDA labeling states that ultramicrosize griseofulvin has greater oral absorption than conventional griseofulvin at equivalent nominal doses, allowing lower administered quantities in some products.[1]

The principal marketed reference product has been Gris-PEG, supplied as 125 mg and 250 mg tablets. Griseofulvin is practically insoluble in water, so particle size, wetting, dispersion, gastrointestinal contents, and food composition directly affect exposure.[1,2]

Key technical characteristics

Attribute	Commercial relevance
Active ingredient	Griseofulvin
Dosage form	Oral tablets; liquid and suspension opportunities
Conventional formulation issue	Very low aqueous solubility
Primary absorption driver	Dissolution and gastrointestinal dispersion
Food effect	Absorption is improved when administered with a fatty meal
Typical formulation objective	Increase surface area and maintain uniform particle dispersion
Regulatory pathway for generics	Abbreviated New Drug Application, or ANDA
Biologic risk	None; griseofulvin is a small molecule
Patent position	Core compound and historic particle-size claims are generally expired or commercially weak

How does particle size affect griseofulvin absorption?

Particle-size reduction increases specific surface area and can accelerate dissolution under gastrointestinal conditions. For a poorly soluble active pharmaceutical ingredient, the benefit depends on maintaining deagglomeration and wetting after compression or dispersion.

The commercial distinction between microsize and ultramicrosize griseofulvin is therefore a formulation-performance distinction rather than a new chemical entity distinction. The particle-size reduction does not eliminate the food effect. FDA labeling continues to recommend administration with fatty food to improve absorption.[1]

Critical controls include:

• Particle-size distribution, including D50 and upper-tail agglomerate control.
• Specific surface area.
• Solid-state form and crystallinity.
• Wetting behavior.
• Blend uniformity at low drug loading.
• Dissolution under fed and fasted conditions.
• Stability against particle growth and agglomeration.
• Uniformity of delivered dose in suspensions and liquids.

A formulation that uses ultramicronized material but produces hard agglomerates after granulation may lose much of the dissolution advantage. Excipient selection must therefore be assessed together with the manufacturing process.

What excipients are suitable for ultramicrosize griseofulvin tablets?

The core excipient strategy should improve wetting, prevent agglomeration, support robust tablet manufacture, and preserve rapid dissolution. A conventional immediate-release tablet can use a relatively simple excipient system, while a differentiated product may require a multi-component enabling formulation.

Recommended excipient functions

Excipient function	Candidate excipient classes	Development purpose
Dilution	Lactose, microcrystalline cellulose, mannitol, dibasic calcium phosphate	Supports tablet weight and content uniformity
Disintegration	Croscarmellose sodium, crospovidone, sodium starch glycolate	Promotes rapid tablet breakup
Wetting	Sodium lauryl sulfate, poloxamers, polysorbates	Improves contact between particles and gastrointestinal fluid
Granulation or binding	Povidone, copovidone, hydroxypropyl cellulose	Controls tablet strength and granule formation
Glidant	Colloidal silicon dioxide	Improves powder flow and reduces segregation
Lubrication	Magnesium stearate, sodium stearyl fumarate	Supports compression and ejection
Taste masking	Coatings, ion-exchange resins, lipid matrices, polymers	Enables pediatric and chewable products
Suspension stabilization	Xanthan gum, hypromellose, sodium carboxymethylcellulose	Limits settling and supports dose uniformity
Wetting and suspension aid	Poloxamer, polysorbate, glycerol, propylene glycol	Improves dispersion and redispersibility
Lipid delivery	Medium-chain triglycerides, glyceryl esters, phospholipids	May improve solubilization and fed-state performance

The lowest-risk commercial strategy is a conventional immediate-release tablet with a wetting agent, superdisintegrant, standard filler, glidant, and lubricant. This approach minimizes formulation complexity and is more compatible with an ANDA strategy.

Excipient risks in tablets

Excessive hydrophobic lubricant can slow wetting and dissolution, particularly in a formulation already dependent on particle-size reduction. Sodium lauryl sulfate can improve dissolution but may create tolerability, foaming, or processing issues at higher levels. Lactose can create compatibility or labeling constraints for patients with lactose intolerance, although it remains a common tablet diluent.

Microcrystalline cellulose can improve compactability but may reduce the proportion of ultramicronized drug that is immediately available if the blend segregates or the drug adheres strongly to the carrier. Direct compression may be attractive for cost, but wet granulation can provide better control of content uniformity and dust management.

What formulation patents protect ultramicrosize griseofulvin?

Historic intellectual-property protection for ultramicrosize griseofulvin focused on particle size, dosage strength, manufacturing processes, and pharmaceutical compositions. The principal commercial product and its underlying formulation technology date from an earlier generation of drug development.

A practical patent review should separate four categories:

1. Composition-of-matter patents. These cover griseofulvin itself and are expired.
2. Particle-size patents. These may cover ultramicronized or finely divided griseofulvin and associated manufacturing methods. Historic claims are likely expired or vulnerable to prior-art challenges.
3. Formulation patents. These may cover specific excipient combinations, suspensions, coatings, or enhanced-dissolution systems.
4. Method-of-use patents. These could cover treatment regimens, but broad antifungal indications are unlikely to create meaningful current exclusivity.

The key commercial issue is not whether any historical patent exists. It is whether an unexpired, enforceable claim covers the specific particle-size distribution, excipient composition, manufacturing process, or delivery system used by a proposed product.

No current patent position should be inferred solely from the product name "ultramicrosize griseofulvin." A freedom-to-operate review should examine U.S. Patent and Trademark Office records, FDA Orange Book entries, assignment records, and litigation databases.

What is the FDA regulatory status of ultramicrosize griseofulvin?

Griseofulvin is an FDA-approved small-molecule antifungal. The reference product category includes ultramicrosize tablets, historically marketed as Gris-PEG. FDA labeling identifies the drug as an oral product for dermatophyte infections and includes pediatric dosing information for selected indications.[1]

A generic tablet may generally pursue the ANDA pathway if it matches the reference product in active ingredient, dosage form, strength, route, and labeling requirements, subject to FDA bioequivalence and product-specific guidance.

Regulatory considerations

Issue	Impact
Reference product	Required for ANDA product selection and bioequivalence
Dosage form	Immediate-release tablet products have the clearest pathway
Food effect	Fed-state performance may be relevant because labeling recommends fatty food
Particle size	Material attribute that can affect dissolution and exposure
In vitro dissolution	Important for formulation discrimination and batch release
Clinical endpoint	Usually avoided in an ANDA if bioequivalence can be demonstrated
Pediatric liquid	May require additional formulation, stability, dosing-device, and labeling work
New delivery system	Could require a 505(b)(2) pathway if relying on new clinical or pharmacokinetic data

A liquid, chewable, or lipid-based formulation may not qualify as a straightforward generic substitute if it differs materially from the reference dosage form or requires new clinical evidence. Such products may be candidates for a 505(b)(2) application rather than an ANDA.

When does ultramicrosize griseofulvin lose exclusivity?

The core small-molecule exclusivity has expired. Griseofulvin has been used clinically for decades, and its basic active-ingredient and antifungal-use rights do not provide a current barrier to generic development.

The relevant commercial protection questions are:

• Whether the reference product has an active Orange Book patent listing.
• Whether a listed patent remains within its enforceable term.
• Whether any pediatric exclusivity or regulatory exclusivity remains.
• Whether a specific formulation or dosage form is separately protected.
• Whether a supplier controls a proprietary ultramicronization process.
• Whether trade secrets, quality specifications, or manufacturing know-how create practical barriers.

For an established product such as ultramicrosize griseofulvin, exclusivity loss is principally a historical event. Current competition is more likely to be constrained by market size, regulatory economics, manufacturing capability, and product availability than by patent term.

What Paragraph IV challenges and generic entry risks exist?

A Paragraph IV certification is relevant only if an ANDA applicant challenges an unexpired patent listed for the reference product. For a legacy griseofulvin product, the expected patent risk is lower than for recently approved drugs, but the absence of a meaningful patent barrier does not eliminate litigation risk.

Potential dispute areas include:

• Whether a generic meets the claimed ultramicronized particle-size range.
• Whether a formulation infringes a composition claim.
• Whether a manufacturing process uses a protected milling or precipitation step.
• Whether a proposed label includes an allegedly patented method of use.
• Whether a formulation patent was properly listed in the Orange Book.
• Whether a patent claim is invalid for anticipation or obviousness.

Generic entry scenarios include:

Scenario	Likely commercial effect
Conventional ultramicrosize tablet	Fastest route to price competition
Microsize tablet	May compete on cost but could require different strength and bioequivalence strategy
Oral suspension	Differentiates through pediatric usability
Chewable tablet	Addresses swallowing and administration barriers
Lipid-enhanced formulation	May support premium positioning if exposure is improved
Compounded suspension	Competes in limited channels but lacks full commercial product advantages
Veterinary formulation	Separate opportunity with different regulatory and channel requirements

What excipients are best for a pediatric griseofulvin suspension?

A pediatric suspension is the most commercially credible excipient-led opportunity. Griseofulvin has pediatric use, particularly for tinea capitis, but tablets can create swallowing and dose-adjustment problems.

A robust suspension requires:

• Controlled particle size without rapid agglomeration.
• A wetting system that supports redispersion.
• A suspending polymer with acceptable viscosity.
• A preservative system compatible with pH and packaging.
• Flavor and sweetener systems that suppress griseofulvin bitterness.
• A dosing syringe calibrated to the approved concentration.
• Container-closure protection against sedimentation, evaporation, and microbial ingress.

Potential platforms include an aqueous suspension, a dry powder for reconstitution, and a taste-masked multiparticulate suspension. The dry powder format may improve stability, while a ready-to-use suspension may reduce caregiver preparation errors.

The main development risks are sedimentation, caking, dose nonuniformity after partial settling, microbial stability, and poor palatability. Taste masking is particularly important because dose adherence affects the commercial value of an otherwise effective product.

How can lipid and solubility-enhancing excipients improve the product?

Griseofulvin is a lipophilic, poorly water-soluble compound. Lipid-based systems may increase apparent solubilization in the gastrointestinal tract and reduce sensitivity to inconsistent meal composition. Candidate systems include self-emulsifying drug delivery systems, medium-chain triglycerides, phospholipids, and surfactant-containing dispersions.

The commercial opportunity is strongest where a formulation can demonstrate one or more of the following:

• Lower variability between fed and fasted administration.
• Faster onset of measurable exposure.
• Lower dose or reduced tablet burden.
• More consistent exposure in patients with poor dietary intake.
• Improved absorption in pediatric patients.
• Better performance than a conventional ultramicrosize tablet.

The main regulatory risk is that a lipid formulation may require clinical pharmacokinetic studies rather than relying solely on conventional dissolution and bioequivalence evidence. Surfactant tolerability, oxidation, capsule compatibility, and long-term physical stability also require evaluation.

How strong is the patent estate for ultramicrosize griseofulvin?

The patent estate is commercially weak for the core product and potentially stronger for new delivery platforms.

IP category	Expected strength
Griseofulvin compound	Very weak; historic protection expired
General antifungal use	Very weak
Ultramicronized particle concept	Historically important but likely expired or limited
Specific particle-size distribution	Potentially relevant only if an unexpired claim exists
Standard tablet excipients	Weak and easy to design around
Pediatric taste-masked suspension	Moderate if claims are narrow and technically supported
Lipid or self-emulsifying formulation	Moderate to strong if pharmacokinetic benefit is demonstrated
Novel manufacturing process	Moderate if process-specific and difficult to circumvent
Device-enabled dosing system	Moderate, but usually separate from drug exclusivity

The best patent strategy is to claim measurable performance and formulation architecture, not the broad concept of using finely divided griseofulvin. Useful claim elements could include a defined particle-size distribution, dissolution threshold, excipient ratio, redispersibility criterion, taste-masking structure, or fed-state pharmacokinetic profile.

Which companies are competing in griseofulvin?

Competition is fragmented and product availability can vary by country and channel. Historic branded supply has included Gris-PEG, while generic manufacturers have supplied griseofulvin tablets and other dosage forms at different times.

The relevant competitive groups are:

• Generic oral solid-dose manufacturers.
• Specialty pharmaceutical companies maintaining legacy antifungal products.
• Contract manufacturers with micronization capability.
• Compounding pharmacies supplying extemporaneous pediatric suspensions.
• Veterinary pharmaceutical companies using griseofulvin in animal products.
• Reformulation companies targeting pediatric or enhanced-absorption products.

The market is unlikely to support a large number of premium entrants because griseofulvin competes with newer antifungal agents, including terbinafine and azole therapies. A differentiated product therefore needs a clear advantage in pediatric administration, supply continuity, adherence, or pharmacokinetic consistency.

What commercial opportunities exist for ultramicrosize griseofulvin?

1. Reliable generic tablets

A supply-focused generic can compete where incumbent availability is inconsistent. The value proposition is manufacturing reliability, stable sourcing of ultramicronized API, and consistent dissolution rather than patent exclusivity.

2. Pediatric oral suspension

This is the strongest formulation opportunity. A ready-to-use or reconstituted suspension could address swallowing limitations, weight-based dosing, and adherence problems. A taste-masked product with a dosing syringe could support premium pricing relative to commodity tablets.

3. Chewable or orally disintegrating dosage forms

These products may improve administration for children and patients unable to swallow tablets. The main technical challenges are bitterness, high dose loading, friability, and maintaining ultramicronized dispersion during compression.

4. Food-effect reduction

A formulation that reduces dependence on a fatty meal could offer a clinically relevant benefit. This opportunity requires pharmacokinetic evidence and may support a 505(b)(2) strategy if the product is materially different from the reference tablet.

5. Veterinary products

Griseofulvin has veterinary applications, particularly for dermatophyte infections in cats and other animals. Veterinary formulations can use flavored suspensions, transdermal concepts, or species-specific dosing presentations, subject to applicable animal-drug requirements. Safety and species-specific toxicity must be addressed separately from human products.

6. Contract development and manufacturing

A manufacturer with validated micronization, particle engineering, and suspension technology could generate value through contract development services, API supply, or licensing. The manufacturing process may be more defensible than a standard tablet formulation.

How does ultramicrosize griseofulvin compare with competing antifungals?

Product	Main advantage	Main limitation versus ultramicrosize griseofulvin
Griseofulvin	Long clinical history and established pediatric use	Long treatment courses and food-dependent absorption
Terbinafine	Often shorter treatment for dermatophyte infection	Different safety, labeling, and pediatric considerations
Fluconazole	Convenient dosing and broad clinical use	May not be preferred for all dermatophyte infections
Itraconazole	Broad antifungal spectrum	Drug interactions and variable absorption
Ketoconazole	Historical topical and systemic use	Systemic safety limitations
Topical antifungals	Lower systemic exposure	Limited utility for scalp, nail, or extensive infection

Griseofulvin remains relevant where clinical familiarity, pediatric use, or organism-specific treatment considerations favor it. Its commercial weakness is the combination of low solubility, food dependence, prolonged therapy, and competition from newer agents.

What manufacturing and IP barriers affect commercialization?

The principal manufacturing barriers are technical rather than legal.

API and particle-engineering barriers

• Reliable supply of ultramicronized griseofulvin.
• Control of electrostatic charging and powder cohesion.
• Prevention of agglomeration during transport.
• Worker exposure management during micronization.
• Reproducible particle-size testing.
• Scale-up from laboratory milling to commercial production.

Finished-product barriers

• Maintaining rapid dissolution after compression.
• Avoiding segregation in low-dose blends.
• Achieving uniform suspension concentration.
• Preserving taste-masked particles during storage.
• Controlling oxidation in lipid formulations.
• Establishing suitable dissolution methods that discriminate between batches.

Trade secrets surrounding milling parameters, surface treatment, dispersion energy, and suspension processing may create practical protection even where patent protection is limited. These barriers can support licensing or supply agreements but generally do not prevent a capable competitor from developing an alternative process.

What revenue exposure and launch economics should investors consider?

Ultramicrosize griseofulvin is a mature, low-to-moderate revenue opportunity. The commodity tablet segment is likely to face price pressure and limited market expansion. Revenue potential is higher for products that solve a defined administration or absorption problem.

Commercial attractiveness can be ranked as follows:

Opportunity	Market potential	Margin potential	Development risk
Standard generic tablet	Moderate volume	Low	Low to moderate
Pediatric suspension	Moderate	Moderate to high	Moderate
Chewable tablet	Niche to moderate	Moderate	Moderate
Lipid-enhanced product	Niche	High if differentiated	High
Veterinary formulation	Niche	Moderate	Moderate
API micronization and supply	Moderate	Moderate	Moderate
Novel combination product	Unclear	Potentially high	High

A launch plan should prioritize a product with a low regulatory burden and a clear supply or administration advantage. A standard tablet can establish market presence, while a pediatric suspension or differentiated delivery system can create a higher-margin extension.

Key Takeaways

• Ultramicrosize griseofulvin improves the dissolution-related performance of griseofulvin but does not eliminate the food effect.
• Core compound and historic product protection are not the principal barriers to generic entry.
• The strongest formulation opportunity is a palatable, dose-uniform pediatric suspension.
• Tablet development should prioritize wetting, rapid disintegration, agglomeration control, and dissolution preservation.
• Lipid and self-emulsifying systems may support premium products but carry higher pharmacokinetic and regulatory risk.
• The best patent opportunities are narrow claims covering particle-size distribution, formulation architecture, measurable dissolution, taste masking, or food-effect reduction.
• Commercial value is likely to come from product availability, pediatric usability, and manufacturing reliability rather than broad exclusivity.
• No biosimilar pathway applies because griseofulvin is a small molecule.
• Generic entry risk is high for conventional tablets and lower for technically differentiated delivery systems.

FAQs

Is ultramicrosize griseofulvin the same as microsize griseofulvin?

No. Both use reduced particle size, but ultramicrosize griseofulvin is engineered to provide smaller particles and improved absorption relative to conventional microsize material. The products should not be treated as automatically interchangeable without regulatory and bioequivalence support.[1]

Can ultramicrosize griseofulvin be formulated as an oral liquid?

Yes. An oral liquid is technically feasible, but it requires suspension stabilization, taste masking, microbial control, redispersibility testing, and a validated dosing device. A dry powder for reconstitution may offer better stability than a ready-to-use suspension.

Does a fatty meal remain necessary with ultramicrosize griseofulvin?

FDA labeling recommends administration with fatty food because food can increase absorption. A new formulation would need evidence to support any claim that it reduces or eliminates this administration requirement.[1]

Is a new ultramicrosize griseofulvin product eligible for orphan-drug exclusivity?

Generally, the broad dermatophyte indications associated with griseofulvin are not expected to qualify as orphan indications. Orphan eligibility would depend on a specific rare disease or population and current FDA criteria, not on the ultramicronized formulation alone.

Can a formulation patent create meaningful protection after griseofulvin patents expire?

Yes. A narrowly drafted formulation patent can provide protection for a new suspension, lipid system, taste-masking structure, or performance-defined composition. Its commercial value depends on claim breadth, enforceability, design-around options, and whether the product obtains a market position before competing formulations appear.

References

1. U.S. Food and Drug Administration. (n.d.). Gris-PEG (griseofulvin ultramicrosize) tablets prescribing information. FDA/DailyMed labeling.

2. National Library of Medicine. (n.d.). Griseofulvin: Drug information and labeling. DailyMed.

3. U.S. Food and Drug Administration. (n.d.). Orange Book: Approved drug products with therapeutic equivalence evaluations. FDA.

4. U.S. Food and Drug Administration. (n.d.). Approved drug products and product-specific guidance. FDA.

5. National Center for Biotechnology Information. (n.d.). Griseofulvin compound summary. PubChem.