List of Excipients in Branded Drug EUCRISA

Company	Tradename	Ingredient	NDC	Excipient	Potential Generic Entry
Pfizer Laboratories Div Pfizer Inc	EUCRISA	crisaborole	55724-211	BUTYLATED HYDROXYTOLUENE	2029-12-29
Pfizer Laboratories Div Pfizer Inc	EUCRISA	crisaborole	55724-211	EDETATE CALCIUM DISODIUM	2029-12-29
Pfizer Laboratories Div Pfizer Inc	EUCRISA	crisaborole	55724-211	GLYCERYL MONOSTEARATE	2029-12-29
Pfizer Laboratories Div Pfizer Inc	EUCRISA	crisaborole	55724-211	PARAFFIN	2029-12-29

EUCRISA Excipient Strategy and Commercial Opportunities for Crisaborole Ointment

Last updated: September 4, 2026

EUCRISA is a crisaborole 2% topical ointment for mild-to-moderate atopic dermatitis in patients age 3 months and older. Its excipient system is anhydrous and relatively simple: white petrolatum, propylene glycol, mono- and diglycerides, paraffin, and sodium edetate.[1] The principal commercial opportunities are generic formulation development, excipient substitution, lower-irritation reformulation, pediatric usability, packaging optimization, and geographic expansion.

The formulation is commercially attractive because it combines a branded active ingredient with a conventional ointment base. The main development challenge is reproducing the product’s critical quality attributes, including drug distribution, rheology, spreadability, skin feel, stability, and topical performance.

What excipients are used in EUCRISA?

EUCRISA contains crisaborole 2% w/w as the active pharmaceutical ingredient. The inactive ingredients listed in the U.S. prescribing information are:

Excipient	Likely formulation function
White petrolatum	Primary occlusive ointment base and emollient
Propylene glycol	Solvent, humectant, and skin-penetration aid
Mono- and diglycerides	Emollient, consistency modifier, and dispersion aid
Paraffin	Stiffening agent, occlusive hydrocarbon, and rheology modifier
Sodium edetate	Chelating agent and stability aid

The formulation is an ointment rather than a cream or lotion. It does not rely on water as the principal vehicle, which reduces the need for a conventional antimicrobial preservative system and limits risks associated with aqueous microbial growth.

The excipient combination also supports anhydrous processing. White petrolatum and paraffin create the continuous hydrocarbon phase. Mono- and diglycerides can modify texture and assist in distributing crisaborole. Propylene glycol introduces a more polar component into an otherwise lipophilic base and may affect solubilization, drug release, and skin permeation.

How does the EUCRISA formulation affect product performance?

The commercial performance of EUCRISA depends on more than the 2% crisaborole concentration. The ointment base influences:

• Application force and spreadability
• Drug uniformity across the tube
• Residence time on the skin
• Occlusion and moisturization
• Drug release from the vehicle
• Skin penetration
• Residual greasiness
• Patient willingness to apply the product
• Stability during storage and use

For a semisolid topical product, formulation sameness is difficult to assess through active-ingredient strength alone. The relevant development targets include viscosity, yield stress, particle or molecular distribution, polymorphic state, water activity, droplet or phase structure, and in vitro release behavior.

Propylene glycol is a particularly important design variable. It may improve drug solubilization and delivery but can contribute to local irritation or sensitization in susceptible patients. The EUCRISA label identifies application-site burning or stinging as a reported adverse reaction and warns about hypersensitivity reactions.[1] A reformulation that reduces propylene glycol or replaces it with another solvent could target improved tolerability, although it would require evidence that drug release and clinical performance remain acceptable.

What formulation patents protect EUCRISA?

EUCRISA’s principal intellectual-property value is associated with crisaborole chemistry, pharmaceutical compositions, topical use, and manufacturing technology. The product was developed by Anacor Pharmaceuticals and later commercialized by Pfizer after Pfizer acquired Anacor in 2016.[2]

The relevant patent categories include:

Patent category	Commercial purpose
Crisaborole composition patents	Protect the active molecule and related boron-containing compounds
Pharmaceutical composition patents	Cover topical preparations containing crisaborole
Method-of-use patents	Cover treatment of atopic dermatitis and related dermatologic conditions
Manufacturing patents	Protect synthesis, purification, crystallization, or solid-form control
Formulation patents	Protect particular vehicles, concentrations, delivery systems, or stability profiles

The strength of a formulation patent depends on its claim scope and prosecution history. A claim directed broadly to “a topical composition comprising crisaborole” may face validity or written-description challenges if the technology was already known. Claims tied to specific concentration ranges, excipient ratios, particle sizes, release profiles, or manufacturing parameters can create more focused barriers.

Public commercial databases commonly associate EUCRISA with U.S. patents including U.S. Patent Nos. 8,598,140 and 9,018,311. Patent status and expiration dates should be evaluated against current USPTO records and the FDA Orange Book because terminal disclaimers, patent-term adjustment, pediatric extensions, reissued patents, and listing changes can affect the operative date.[3][4]

When does EUCRISA lose exclusivity?

EUCRISA received U.S. Food and Drug Administration approval on December 14, 2016, for topical treatment of mild-to-moderate atopic dermatitis in adults and pediatric patients 2 years and older at initial approval.[1] The approved age range was later expanded to patients 3 months and older.[5]

The market-exclusivity analysis has several components:

Exclusivity component	EUCRISA relevance
New chemical entity exclusivity	The FDA’s Orange Book and Drugs@FDA records control the applicable period
Patent exclusivity	Depends on listed patents, expiration dates, and any patent-term adjustments
Pediatric exclusivity	May extend qualifying listed patents by six months if granted
Regulatory exclusivity for labeling	Can affect approval of competing method-of-use labeling
Formulation protection	May delay or complicate competing products with non-equivalent vehicles

A generic applicant may seek approval before every patent expires by certifying that a listed patent is invalid, unenforceable, or will not be infringed. The commercial launch date then depends on the certification, litigation, any 30-month stay, settlement terms, and court outcomes.

What is the Orange Book status of EUCRISA?

EUCRISA is a small-molecule prescription drug, not a biologic. Its U.S. generic pathway is generally an abbreviated new drug application, subject to the requirements applicable to topical semisolid products.

The Orange Book is the controlling source for currently listed patents and exclusivity information.[3] A commercial review should distinguish:

1. Patents listed against the reference listed drug.
2. Patents that have expired.
3. Patents that remain listed but are not necessarily blocking under every proposed formulation.
4. Regulatory exclusivity that may have ended independently of patent protection.
5. Paragraph IV certifications filed by individual ANDA applicants.

A patent listed for a method of use may be less restrictive for a generic applicant that uses a permissible “skinny label,” provided the proposed labeling and marketing conduct avoid the patented indication or method. That approach is fact-specific and can create litigation risk if the branded company alleges induced infringement.

Which companies are challenging EUCRISA?

The relevant competitive group includes:

• Generic pharmaceutical companies developing crisaborole ointments.
• Contract development and manufacturing organizations with semisolid expertise.
• Branded dermatology companies developing alternative nonsteroidal treatments.
• Excipient suppliers offering differentiated hydrocarbon bases, emulsion systems, or skin-delivery technologies.
• Specialty dermatology companies seeking regional licensing or co-promotion rights.

Public information on individual Paragraph IV filers, litigation, or settlement agreements must be verified through FDA records, court dockets, and company disclosures. The absence of a publicly visible challenge does not establish that no ANDA has been filed, because filing and litigation information may emerge at different times.

A generic challenger’s main technical issue is not the active ingredient alone. It is demonstrating that the proposed ointment has acceptable pharmaceutical equivalence and comparable product performance. The applicant must manage differences in excipient grade, source, manufacturing temperature, mixing sequence, filling process, tube material, and storage conditions.

What excipient strategies offer the strongest commercial opportunity?

Preservative-free anhydrous ointments

The current EUCRISA architecture already supports a preservative-free commercial position because the vehicle is substantially anhydrous. A competing product can retain this advantage while improving sensory properties, application smoothness, or residue.

The opportunity is strongest where a new excipient system produces a measurable benefit without materially changing drug release or skin penetration.

Propylene glycol reduction or replacement

Replacing or reducing propylene glycol could target patients who experience irritation. Candidate approaches include:

• Alternative glycols
• Polyols
• Ester-based solvents
• Lipid-compatible solubilizers
• Mixed solvent systems
• Encapsulated or dispersed crisaborole

The main risk is that propylene glycol may contribute to the formulation’s drug-delivery profile. Removal could reduce release or penetration, increase crystallization, or alter dose uniformity.

Improved sensory profile

Ointments can be effective but may be perceived as greasy. A competing crisaborole product could use a lighter hydrocarbon system, a silicone-containing vehicle, an oleogel, or a structured lipid base. The commercial target would be improved spreadability and lower residue without losing occlusion.

This strategy is particularly relevant to facial, intertriginous, and pediatric use, where product feel can affect adherence.

Pediatric packaging

EUCRISA is approved for infants as young as 3 months.[5] Pediatric packaging can create a practical advantage through:

• Small-volume tubes
• Metered-dose dispensers
• Low-residue tube materials
• Tamper-evident closures
• Reduced product waste
• Easier dosing instructions

Packaging claims generally do not create the same patent barrier as composition claims, but they can support differentiation and improve pharmacy and caregiver acceptance.

Tube and container-closure compatibility

Ointments can interact with tube liners, elastomers, adhesives, and plastic containers. A commercial developer can optimize:

• Extractables and leachables
• Product loss in the shoulder and nozzle
• Oxygen and moisture transmission
• Crystallization near the tube opening
• Closure torque
• Dispensing force

Aluminum and laminate tubes may provide different barrier and compatibility profiles than conventional plastic tubes. Container selection can also support a stability claim or reduce manufacturing losses.

What manufacturing and IP barriers affect crisaborole products?

The principal manufacturing barriers are process control and analytical characterization. Relevant controls include:

• Active-ingredient particle size or solid-state form
• Excipient temperature during incorporation
• Mixing energy and shear
• Order of addition
• Deaeration
• Homogeneity sampling
• Filling temperature
• Tube-fill accuracy
• Long-term and accelerated stability

Crisaborole is a boron-containing small molecule. Boron chemistry can create specialized requirements for impurity control, assay methods, residual solvents, and degradation-product characterization. A supplier that can provide consistent pharmaceutical-grade crisaborole and validated impurity profiles may have leverage in licensing or contract manufacturing discussions.

Excipient suppliers can create value through qualified grades rather than novel molecules. A consistent petrolatum or paraffin grade with controlled hydrocarbon distribution, low impurities, and reliable rheology may reduce batch variability. The same applies to mono- and diglycerides, where composition and melting behavior can affect ointment texture.

How strong is the EUCRISA patent estate?

EUCRISA’s estate is stronger when viewed as a combination of active-ingredient protection, formulation know-how, regulatory exclusivity, and manufacturing controls. It is weaker if a competitor can develop a non-infringing vehicle with equivalent clinical performance and obtain approval through an abbreviated pathway.

Asset	Relative defensive value
Crisaborole molecule claims	High, if unexpired and enforceable
Broad topical composition claims	Moderate to high, depending on claim construction
Narrow excipient-ratio claims	Moderate, with design-around potential
Method-of-use claims	Variable, depending on label and induced-infringement exposure
Manufacturing know-how	Moderate, particularly where analytical replication is difficult
Packaging claims	Usually limited unless tied to a protected delivery system

The most credible generic design-around strategy is likely to preserve the 2% active concentration while changing the vehicle, excipient ratios, manufacturing process, or packaging. The most credible branded defense is to rely on listed patents covering the active ingredient or broad pharmaceutical compositions, then use formulation and clinical-performance data to distinguish the reference product from alternative semisolids.

What generic launch scenarios exist for EUCRISA?

Early Paragraph IV launch

A challenger may file an ANDA with a Paragraph IV certification and trigger patent litigation. Commercial entry could occur after a favorable court decision, an agreed launch date, or a settlement.

At-risk launch

A generic company could launch before final patent resolution. This exposes the company to damages, injunction risk, and potential disruption of supply contracts. The attractiveness of this route depends on the expected size of the EUCRISA market and the perceived strength of the listed patents.

Post-expiry launch

This is the lowest-risk pathway but may attract several competitors simultaneously. Price erosion would likely be greater if multiple ANDA products launch near the same date.

Authorized generic or licensed alternative

The brand owner could license regional rights, launch an authorized generic, or partner with a dermatology company. Such arrangements may preserve channel access while reducing the impact of independent generic entry.

What licensing deals and commercial partnerships are available?

The most realistic opportunities are:

1. Regional commercialization rights outside the United States.
2. Authorized-generic supply.
3. Reformulated crisaborole products using a differentiated vehicle.
4. Pediatric or adherence-focused packaging.
5. Contract manufacturing of semisolid drug products.
6. Excipient supply agreements with quality and continuity commitments.
7. Combination products pairing crisaborole with barrier-repair or moisturization technologies.

Because EUCRISA is a small-molecule topical product, biosimilar licensing is not relevant. The applicable competitive models are ANDA generics, 505(b)(2) reformulations, branded line extensions, and private-label or regional products.

What is the FDA regulatory status of EUCRISA?

The FDA approved EUCRISA under a new drug application for topical atopic dermatitis.[1] The product is a prescription ointment. The label now covers patients 3 months of age and older.[5]

A reformulated crisaborole product may require an ANDA if it can meet the applicable pharmaceutical-equivalence and bioequivalence requirements. A product with a materially different vehicle, delivery mechanism, concentration, indication, or clinical positioning may require a 505(b)(2) application or a full NDA, depending on the development strategy and FDA assessment.

Key Takeaways

• EUCRISA uses a simple, anhydrous excipient system based on white petrolatum, propylene glycol, mono- and diglycerides, paraffin, and sodium edetate.
• The largest formulation opportunity is improving tolerability and sensory performance without disrupting crisaborole release or skin penetration.
• Propylene glycol is the key excipient design variable because it may support delivery while contributing to irritation risk.
• Generic developers must match semisolid performance, not only active-ingredient strength.
• Excipient suppliers can create value through controlled pharmaceutical grades, consistent rheology, and validated supply continuity.
• Crisaborole is a small molecule, so biosimilar competition is not applicable.
• The relevant regulatory pathways are ANDA, 505(b)(2), and NDA development.
• Current Orange Book listings, Paragraph IV certifications, patent litigation, and settlement terms determine the actual generic-entry timetable.
• The strongest commercial strategies are generic substitution, lower-irritation reformulation, pediatric packaging, regional licensing, and authorized-generic supply.

FAQs About EUCRISA Excipients and Commercial Strategy

Can propylene glycol be removed from a crisaborole ointment?

Yes, but removal may change drug solubility, release, crystallization, skin penetration, and texture. A replacement vehicle would require comparative pharmaceutical and regulatory development.

Is EUCRISA a preservative-free product?

The U.S. label lists no conventional antimicrobial preservative. Its substantially anhydrous ointment base reduces the need for a water-phase preservation system.[1]

Can a generic company change the EUCRISA excipients?

A generic applicant may use a different excipient system if the product satisfies applicable FDA requirements for pharmaceutical equivalence, bioequivalence, quality, labeling, and safety. The permissible degree of variation depends on the product classification and FDA guidance.

Is crisaborole eligible for a biosimilar pathway?

No. Crisaborole is a small-molecule active ingredient. Competing products would generally use generic-drug or new-drug pathways rather than the U.S. biosimilar pathway.

What is the most valuable excipient opportunity for EUCRISA?

A lower-irritation, less greasy anhydrous vehicle has the clearest commercial rationale. It could target adherence, pediatric use, facial application, and patients who discontinue treatment because of burning or ointment residue.

References

1. U.S. Food and Drug Administration. (2016). EUCRISA (crisaborole) ointment, 2%: Prescribing information. Pfizer Laboratories.

2. Pfizer Inc. (2016). Pfizer completes acquisition of Anacor Pharmaceuticals. Pfizer investor and corporate communications.

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

4. United States Patent and Trademark Office. (n.d.). Patent Center and patent assignment records. USPTO.

5. U.S. Food and Drug Administration. (2020). FDA approves supplemental application for EUCRISA for pediatric patients 3 months of age and older. FDA.