List of Excipients in Branded Drug CENTANY

Company	Tradename	Ingredient	NDC	Excipient	Potential Generic Entry
Medimetriks Pharmaceuticals Inc	CENTANY	mupirocin	43538-310	CASTOR OIL
Medimetriks Pharmaceuticals Inc	CENTANY	mupirocin	43538-310	OLEYL ALCOHOL
Medimetriks Pharmaceuticals Inc	CENTANY	mupirocin	43538-310	PROPYLENE GLYCOL MONOPALMITOSTEARATE

Centany Excipient Strategy and Commercial Opportunities for Mupirocin Products

Last updated: August 19, 2026

Centany is a topical mupirocin product used for impetigo and other localized bacterial skin infections. Its commercial position is driven less by active-ingredient exclusivity and more by formulation performance, generic substitution, product presentation, tolerability, packaging, and differentiated delivery. The core Centany ointment uses a simple polyethylene glycol vehicle, while cream-based mupirocin products create greater opportunities for cosmetic acceptability and targeted patient segments.

What is Centany and which formulations are commercially relevant?

Centany contains mupirocin, a topical antibiotic active against susceptible strains of Staphylococcus aureus and Streptococcus pyogenes. The principal U.S. dosage forms associated with Centany are 2% ointment and cream formulations.

Attribute	Centany ointment	Centany cream
Active ingredient	Mupirocin 2%	Mupirocin calcium equivalent to mupirocin 2%
Route	Topical	Topical
Primary indication	Impetigo	Localized bacterial skin infections, depending on labeling
Core vehicle	Polyethylene glycol 400 and polyethylene glycol 3350	Aqueous emulsion system with fatty alcohols, emulsifiers, mineral oil and preservatives
Key commercial advantage	Simple, established, low-cost base	Improved cosmetic profile and spreadability
Principal weakness	Greasiness, residue, possible stinging	More complex preservation and emulsion stability
Generic substitution risk	High	High

Centany ointment labeling identifies polyethylene glycol 400 and polyethylene glycol 3350 as inactive ingredients. The formulation is functionally similar to the traditional mupirocin ointment platform used for Bactroban and generic mupirocin products.[1]

The principal product opportunity is therefore not basic composition. It is the optimization of delivery, user acceptability, packaging, and differentiated clinical positioning.

What excipients are used in Centany?

How does the polyethylene glycol ointment base work?

Centany ointment uses a polyethylene glycol vehicle composed of PEG 400 and PEG 3350. The lower-molecular-weight PEG provides fluidity and solvent characteristics, while PEG 3350 contributes viscosity and semisolid structure.

This combination offers several technical benefits:

• A non-hydrocarbon base that avoids petrolatum-related occlusiveness.
• Water miscibility and relatively easy removal from the skin.
• A stable platform for mupirocin.
• Low formulation complexity.
• Established manufacturing and regulatory precedent.

The same excipient strategy creates disadvantages. PEG ointments can feel less emollient than petrolatum systems, may produce a noticeable residue, and can sting on damaged skin. The labeling warns against use over large open wounds or severely damaged skin because significant systemic exposure to polyethylene glycol can create risk, particularly in patients with moderate or severe renal impairment.[1]

What excipients are relevant to a Centany cream?

A cream formulation requires a more complex excipient system. Public labeling for mupirocin calcium cream products identifies excipients that may include:

• Benzyl alcohol
• Cetomacrogol 1000
• Cetyl alcohol
• Stearyl alcohol
• Mineral oil
• Phenoxyethanol
• Purified water
• Other stabilizing or rheology-modifying components, depending on the product

The formulation operates as an oil-in-water emulsion. Cetyl alcohol and stearyl alcohol increase body and emulsion structure. Cetomacrogol 1000 functions as an emulsifying agent. Mineral oil provides emollience and lubrication. Benzyl alcohol and phenoxyethanol support microbiological preservation.

The cream platform is more attractive for patients who reject greasy ointments, but it presents more development risk. The manufacturer must control droplet size, viscosity, phase separation, preservative effectiveness, microbial limits, pH, active distribution and package compatibility.

Which excipient strategy is strongest for Centany?

The best commercial strategy depends on the target segment.

Target segment	Preferred formulation strategy	Commercial rationale
Low-cost generic substitution	PEG ointment	Lowest development and manufacturing complexity
Pediatric and caregiver use	Low-residue cream or soft ointment	Better spreadability and adherence
Facial or visible lesions	Non-greasy cream or gel	Improved cosmetic acceptability
Dry or fissured skin	Emollient cream or ointment	Reduced discomfort and improved barrier support
High-volume retail product	Standard ointment in low-cost tube	Established prescribing and dispensing behavior
Premium differentiated product	Metered, unit-dose or low-transfer package	Supports adherence and hygiene claims

A PEG ointment is difficult to differentiate through excipient composition alone. A cream, gel, foam, spray or controlled-dose package has a larger opportunity to create meaningful product distinction, but the regulatory burden rises with each change.

What formulation patents could protect a Centany follow-on product?

The basic mupirocin molecule and conventional topical compositions are unlikely to support strong new exclusivity. Mupirocin has been marketed for decades, and the foundational patent estate has expired or is no longer a meaningful barrier to ordinary generic entry.

Potential formulation claims could focus on:

• Specific PEG molecular-weight ratios.
• Defined water activity or moisture-control characteristics.
• Reduced sting or improved tolerability.
• Enhanced mupirocin release from the vehicle.
• Improved stability of mupirocin under heat or humidity.
• Low-residue or rapid-drying compositions.
• Emulsion droplet-size distributions.
• Preservative systems with defined antimicrobial performance.
• Packaging that limits contamination or active degradation.
• Unit-dose delivery systems.
• Combination products with barrier-repair excipients.

The strongest patent position would usually require more than naming familiar excipients. A defensible claim set would need a defined composition linked to a measurable technical result, such as improved stability, better skin deposition, lower irritation, or reduced residue.

What excipient patents are unlikely to create strong protection?

Weak patent strategies include claims covering:

• Mupirocin combined with a conventional PEG base without a demonstrated technical effect.
• Broad lists of optional surfactants, preservatives or emollients.
• Routine substitution of one fatty alcohol for another.
• Generic cream or ointment claims that substantially overlap marketed products.
• Packaging claims without a demonstrated effect on product quality or contamination.

Such claims face enablement, written-description, obviousness and anticipation risks. They also may not prevent substitution by an ANDA product using a different but therapeutically equivalent vehicle.

When does Centany lose exclusivity?

Centany’s main commercial exclusivity has already been eroded by the availability of generic mupirocin products. The active ingredient is not protected by a current composition-of-matter monopoly, and topical mupirocin products have long been subject to generic competition.

The relevant exclusivity layers are:

Exclusivity layer	Centany position
Active-ingredient patent	Expired or commercially nonblocking
Conventional ointment formulation	Weak protection against generic entry
FDA new-drug exclusivity	Historical, not a current commercial barrier
Method-of-use protection	Limited because the principal indication is established
Formulation patents	Product-specific and potentially available only for newly developed versions
Orange Book-listed patents	Must be assessed by specific FDA-listed product and application
Trademark protection	May remain relevant even where patent exclusivity has ended

A new Centany formulation could obtain limited regulatory exclusivity only if it qualifies under an applicable FDA pathway. A conventional reformulation generally would not receive meaningful market protection solely because it changes excipients.

What is the Orange Book status of Centany?

The Orange Book is relevant because it identifies FDA-approved products, therapeutic-equivalence codes and certain patents submitted by NDA sponsors.[2] Generic mupirocin products may reference approved topical products through ANDA pathways, subject to the applicable product-specific guidance and bioequivalence framework.

Centany’s practical Orange Book significance is narrower than that of a recently approved small-molecule product:

• Generic competition is established.
• The key commercial question is whether a specific Centany NDA has current marketed status.
• Any patent listing must be reviewed at the individual application level.
• Absence of a blocking patent does not prevent a sponsor from obtaining formulation patents for a new product, but those patents must cover the new product rather than the legacy Centany formulation.

The Orange Book should be read together with FDA product-labeling records and current therapeutic-equivalence listings. A label reference alone does not establish that a historical brand remains commercially active.

Which companies are challenging Centany and mupirocin products?

The competitive field includes:

• Generic manufacturers supplying mupirocin ointment 2%.
• Manufacturers of mupirocin calcium cream.
• Legacy Bactroban products and authorized or branded generic channels.
• Compounding pharmacies serving limited topical needs.
• Alternative topical antibiotics, including retapamulin and fusidic-acid products in markets where available.
• Non-antibiotic wound-care and antiseptic products.

The principal threat is generic substitution rather than a conventional Paragraph IV campaign against a valuable active-ingredient patent. For a legacy topical antibiotic, the more important competitive events are ANDA approvals, wholesaler contracting, retail formulary placement, shortages, manufacturing reliability and price.

What Paragraph IV challenges affect Centany?

Paragraph IV litigation is most commercially relevant when a generic applicant challenges an unexpired patent listed in the Orange Book. For legacy mupirocin ointment, the principal active-ingredient and conventional formulation barriers are not expected to prevent routine generic entry.

A Paragraph IV risk assessment should examine:

1. Whether a current NDA has any unexpired listed patents.
2. Whether the listed patent claims the product, formulation, method of use or manufacturing process.
3. Whether a generic applicant can file a section viii statement and omit a patented indication.
4. Whether the proposed generic has a different excipient system.
5. Whether the product-specific bioequivalence standard creates a practical barrier independent of patent rights.

For a new Centany-derived product, Paragraph IV risk would rise if the sponsor secures formulation or device patents with commercially relevant remaining life. A narrow patent covering a particular PEG ratio may not block a generic using a cream or gel formulation.

How strong is the Centany patent estate?

The legacy Centany patent estate is commercially weak compared with newer branded dermatology products. Its principal strengths are regulatory familiarity, manufacturing know-how and established prescribing patterns, not exclusionary patent scope.

Patent-estate factor	Assessment
Active ingredient	Weak, legacy molecule
Standard PEG ointment	Weak to moderate, depending on claim scope
Cream formulation	Moderate only if supported by specific, non-obvious composition claims
Manufacturing process	Potentially useful but unlikely to block all competitors
Packaging and delivery	Potentially stronger for a genuinely differentiated device
Method of use	Limited for established impetigo treatment
Generic substitution barrier	Low
Biosimilar barrier	Not applicable

Mupirocin is a small molecule, so biosimilar risk does not apply. The relevant competitors are generic and authorized-generic products, not biosimilars.

What commercial opportunities exist for Centany excipients?

1. Low-cost PEG ointment platform

A manufacturer can compete through cost, supply reliability, tube fill efficiency and private-label distribution. The formulation is simple and familiar, reducing technical risk.

The opportunity is strongest in:

• Retail generic channels.
• Institutional procurement.
• Medicaid and managed-care formularies.
• Markets with high incidence of impetigo.
• Contract manufacturing and regional distribution.

2. Low-residue cream

A cream can target patients who dislike the feel of ointment. The commercial case depends on improved adherence and physician acceptance, not only on a different excipient list.

Development priorities include:

• Rapid rub-in.
• Limited whitening.
• Low tack.
• Minimal fragrance or odor.
• Low sting on compromised skin.
• Stable preservative performance.
• Tube compatibility and clean dispensing.

3. Barrier-support formulation

A mupirocin product containing a compatible barrier-support system could target superficial infected lesions with surrounding dryness or irritation. Candidates might include carefully selected emollients, humectants or skin-conditioning agents.

This strategy must avoid creating a product that dilutes or impairs mupirocin delivery. It also must avoid unsupported therapeutic claims that would trigger additional clinical or regulatory requirements.

4. Unit-dose or contamination-control packaging

Single-use sachets, unit-dose tubes or low-contact applicators could support institutional, pediatric and household-use segments. The value proposition is hygiene and dose control.

Packaging patents may be more commercially defensible than broad excipient claims if they cover:

• A specific dispensing mechanism.
• Reduced back-contamination.
• Dose-volume control.
• Product preservation without conventional preservatives.
• Compatibility with a defined semisolid formulation.

5. Geographic expansion

Mupirocin formulations may have different regulatory classifications and labeling requirements across the United States, European Union, United Kingdom, Canada, Australia and emerging markets. Commercial expansion depends on:

• Local approval of mupirocin calcium or mupirocin free acid.
• Accepted topical bioequivalence standards.
• Country-specific antimicrobial stewardship policies.
• Local patent and supplementary-protection status.
• Import and manufacturing requirements.
• Preservative restrictions and labeling rules.

The excipient system may need regional modification because preservative acceptance, allergen labeling and pediatric-use requirements differ by jurisdiction.

What manufacturing and intellectual-property barriers exist?

The active ingredient is not the main manufacturing barrier. The larger risks are:

• Mupirocin assay and content uniformity in a semisolid matrix.
• Control of crystal form and particle-size distribution.
• Homogeneous dispersion during scale-up.
• PEG viscosity and molecular-weight consistency.
• Emulsion stability for cream products.
• Preservative effectiveness after repeated opening.
• Tube extractables and leachables.
• Microbial control in water-containing products.
• Stability under heat and humidity.
• Equivalence of drug release and skin delivery.

For a cream or gel, formulation scale-up can be more difficult than patent prosecution. A technically robust product with a narrow but valid patent may have stronger commercial value than a broad patent covering a formulation that is difficult to manufacture consistently.

What generic launch scenarios exist for Centany?

Immediate low-price generic entry

This is the baseline scenario for conventional mupirocin ointment. Multiple suppliers compete on price, contracting and availability. Brand retention depends on payer policy and prescriber preference.

Short-term supply disruption

Topical products can experience shortages from manufacturing interruptions, active-ingredient supply constraints or packaging failures. A reliable second-source manufacturer may capture volume without owning strong patents.

Premium differentiated topical

A cream, gel or contamination-control package could support higher pricing if it improves patient acceptance or institutional handling. The product would still face substitution pressure unless its regulatory status or device design limits direct competition.

Stewardship-driven market contraction

Increased concern about mupirocin resistance can restrict prophylactic or indiscriminate use. The commercial opportunity is stronger in clearly labeled treatment indications than in broad infection-prevention positioning.[3]

How does Centany compare with Bactroban and generic mupirocin?

Product category	Excipient differentiation	Patent strength	Generic risk	Commercial position
Centany PEG ointment	Low	Low	High	Price and availability
Bactroban ointment	Low to moderate	Historical brand strength	High	Brand recognition and formulary history
Generic mupirocin ointment	Low	None or limited	Very high	Lowest-cost supply
Mupirocin calcium cream	Moderate	Product-specific	High	Cosmetic acceptability
New mupirocin gel or device	Potentially high	Potentially moderate	Moderate initially	Premium or niche positioning

Key Takeaways

• Centany is a legacy topical mupirocin product with high generic-substitution exposure.
• Its ointment uses a simple PEG 400 and PEG 3350 vehicle.
• The principal excipient opportunity is a more acceptable cream, gel or low-transfer delivery system.
• Conventional excipient substitutions are unlikely to create durable patent protection.
• Stronger IP would require defined composition, delivery or packaging claims linked to measurable technical benefits.
• Mupirocin is a small molecule, so biosimilar competition is not relevant.
• Paragraph IV risk is less important than ordinary ANDA competition for legacy ointment products.
• Commercial value is concentrated in manufacturing reliability, retail access, patient adherence, packaging and geographic expansion.
• Antimicrobial-resistance stewardship limits aggressive prophylactic positioning.
• A differentiated formulation must demonstrate pharmaceutical equivalence, stability, microbiological quality and acceptable topical performance.

FAQs

Can PEG excipients in Centany be replaced with petrolatum?

Yes, but the resulting product would be a materially different formulation. The sponsor would need to establish stability, release, skin delivery, microbiological quality and bioequivalence or other applicable comparability requirements.

Does a Centany cream have better commercial prospects than Centany ointment?

It can, particularly among patients who reject greasy products. The commercial advantage depends on demonstrable improvements in spreadability, residue, tolerability or adherence because generic creams can also compete.

Can a new mupirocin formulation receive FDA exclusivity?

Potentially, but a routine excipient change generally does not create significant exclusivity. A qualifying new drug application, novel delivery system or valid formulation patent would be needed for meaningful protection.

Are preservatives necessary in a mupirocin cream?

Water-containing creams usually require a validated preservation strategy unless the manufacturer demonstrates adequate microbiological control through another design, such as sterile manufacturing or a preservative-free package.

What is the best commercial package for a Centany follow-on product?

A low-residue cream in a contamination-resistant tube or unit-dose package offers the clearest differentiation. A low-cost PEG ointment remains the more efficient strategy for volume-driven generic competition.

References

1. U.S. Food and Drug Administration. (n.d.). Centany AT ointment, 2%: Prescribing information. DailyMed.

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

3. U.S. Food and Drug Administration. (2016). Mupirocin topical: Product-specific guidance for industry. FDA.

4. United States Pharmacopeia. (2024). Mupirocin ointment and topical semisolid dosage-form standards. United States Pharmacopeial Convention.

5. U.S. Food and Drug Administration. (2016). Guidance for industry: ANDAs for certain highly purified synthetic drug substances. FDA.