ERYTHROCIN STEARATE Drug Patent Profile

Which patents cover Erythrocin Stearate, and what generic alternatives are available?

Erythrocin Stearate is a drug marketed by Azurity and is included in one NDA.

The generic ingredient in ERYTHROCIN STEARATE is erythromycin stearate. There are one hundred and three drug master file entries for this compound. Additional details are available on the erythromycin stearate profile page.

Summary for ERYTHROCIN STEARATE

US Patents:	0
Applicants:	1
NDAs:	1
Raw Ingredient (Bulk) Api Vendors:	30
Patent Applications:	1,091
DailyMed Link:	ERYTHROCIN STEARATE at DailyMed

US Patents and Regulatory Information for ERYTHROCIN STEARATE

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Exclusivity Expiration
Azurity	ERYTHROCIN STEARATE	erythromycin stearate	TABLET;ORAL	060359-002	Approved Prior to Jan 1, 1982		DISCN	No	No
Azurity	ERYTHROCIN STEARATE	erythromycin stearate	TABLET;ORAL	060359-001	Approved Prior to Jan 1, 1982		DISCN	No	No
Azurity	ERYTHROCIN STEARATE	erythromycin stearate	TABLET;ORAL	060359-003	Approved Prior to Jan 1, 1982		DISCN	No	No

Last updated: July 28, 2026

ERYTHROCIN STEARATE market dynamics and financial trajectory (pricing, volume, demand drivers, and competitive outlook)

Erythrocin Stearate is a branded oral erythromycin antibiotic product whose market profile has shifted toward low-to-mid single-digit brand sales in most developed markets, with sustained demand limited by narrow clinical positioning, oral-tolerance variability, and ongoing substitution to generic erythromycin salts. Financial trajectory is typically characterized by steady erosion of branded pricing power versus generics, intermittent pull-through from clinician familiarity and formularies, and periodic supply and reimbursement disruptions rather than major growth catalysts.

What is ERYTHROCIN STEARATE and how is it used commercially?

Erythrocin Stearate is an oral erythromycin product formulated as erythromycin base stearate for gastrointestinal tolerability and dosing consistency versus other erythromycin salts.

Commercially relevant use cases

• Outpatient treatment of susceptible infections where erythromycin is still chosen for organism susceptibility, alternative options, or patient-specific constraints.
• “Niche” antibiotic positioning in many formularies relative to newer macrolides (clarithromycin, azithromycin) and non-macrolide options.
• Substitute prescribing when preferred agents are contraindicated, unavailable, or not suitable.

Demand sensitivity

• Antibiotics are subject to “watchful prescribing” pressure driven by stewardship programs.
• Seasonal infection patterns can lift volumes, but stewardship controls often dampen year-over-year growth.
• Switches among macrolides occur quickly if a competing agent is preferred for dosing convenience or tolerability.

What market dynamics affect ERYTHROCIN STEARATE sales growth or decline?

1) Generic substitution is the primary structural force Branded erythromycin products face continuous erosion from generic erythromycin formulations. The market dynamics for erythromycin are typically characterized by:

• High therapeutic substitutability across erythromycin salts.
• Rapid payer acceptance of authorized generics and multi-source generics.
• Lower brand willingness-to-pay once multiple generics are established.

2) Stewardship and guideline-driven prescribing Macrolide use is shaped by:

• Resistance and suitability assessments for respiratory and skin infections.
• Local antibiogram patterns that influence clinician selection.
• Stewardship restrictions that reduce overall antibiotic volume when outcomes can be achieved with narrower-spectrum alternatives.

3) Tolerability and adherence dynamics Even within the erythromycin class, adherence is influenced by:

• Gastrointestinal adverse event profiles.
• Dosing frequency and patient tolerance.
• Substitution toward azithromycin regimens that use simpler dosing schedules and often show better adherence.

4) Competitive landscape within macrolides

• Azithromycin and clarithromycin have stronger convenience and brand visibility.
• Erythromycin’s competitive position is “salvage and niche,” not “first-line volume.”

5) Supply chain and raw material volatility Erythromycin and related intermediates can be exposed to:

• API manufacturing concentration.
• Long lead times for certain sourcing.
• Temporary availability constraints that can swing channel stocking and short-term demand.

What does the financial trajectory typically look like for ERYTHROCIN STEARATE?

A branded erythromycin product’s financial trajectory in mature markets usually follows a recognizable pattern:

Phase 1: Peak brand monetization

• Higher list pricing and payer coverage with limited generic access.
• Volume supported by clinician familiarity and formularies that still list brands.

Phase 2: Mid-phase erosion

• Generic launches drive share loss and price declines.
• Revenues decline even if prescriptions remain stable due to reimbursement compression.
• Marketing support often shifts from expansion to retention.

Phase 3: Low-growth, low-margin plateau

• Stable or shrinking volume, driven by narrow patient segments and specific prescriber preferences.
• Financial performance becomes more sensitive to tender contracts, pharmacy stocking practices, and manufacturing uptime than to demand expansion.

Phase 4: Residual brand decline or re-positioning

• If the brand has limited remaining exclusivity, it can decline toward a de minimis share.
• Some brands survive through inertia in specific formularies or by holding contracted channels longer than competitors.

Because “market trajectory” for antibiotics is strongly driven by generic reimbursement dynamics, financial outcomes for ERYTHROCIN STEARATE are expected to be dominated by price and share erosion rather than new clinical adoption.

How does ERYTHROCIN STEARATE pricing and reimbursement typically evolve versus generics?

Branded pricing

• Branded products generally move from premium pricing to constrained net pricing as generics gain formulary acceptance.
• Net revenue compresses from payer rebates, increased utilization management, and generic switch incentives.

Generic pricing

• Generics usually converge toward a low net price depending on:
  • Multi-source competition intensity.
  • Authorized generic presence.
  • Contracting and tender outcomes in institutional channels.

Reimbursement pressure channels

• Retail pharmacy: increased generic preference and substitution.
• Institutional: group purchasing organization tenders and formulary management.
• PBM: step therapy and quantity limits for antibiotic classes.

Net result: branded revenue declines faster than unit volume often declines, because reimbursement is the main driver of financial deterioration post-generic entry.

What generic entry risks exist for ERYTHROCIN STEARATE?

For older small-molecule antibiotics, generic entry risk usually takes the form of:

• High probability of generic coverage because erythromycin salts are straightforward to manufacture once key patents, if any, expire or are cleared.
• Density of low-cost multi-source supply after authorized generic or additional generic approvals.
• Minimal barriers to entry for equivalent-dose products unless formulation-specific or process patents remain enforced.

Primary risks to branded revenue

• Loss of formulary position.
• Loss of contract share in hospitals and clinics.
• Sudden price resets when a new low-priced generic secures favorable PBM or tender placements.

What is the competitive landscape for ERYTHROCIN STEARATE in macrolides?

Direct class substitution

• Azithromycin (oral regimens with convenient dosing)
• Clarithromycin (often preferred for certain outpatient patterns)
• Other erythromycin salt forms (depending on local availability)

Clinical selection drivers

• Dosing schedule preference
• Tolerability profile
• Drug-drug interaction profiles within macrolides
• Local guideline and resistance patterns

Commercial selection drivers

• PBM formulary listing status
• Margin and contract rebates
• Institutional tender pricing

In practice, erythromycin stearate is typically less competitive on convenience and is therefore not the default for large-volume respiratory indications.

What FDA and Orange Book dynamics typically matter for ERYTHROCIN STEARATE?

For an older branded antibiotic, the Orange Book profile usually shows:

• Early listed active ingredient approvals for which many related patents have already expired.
• Remaining patent life, if any, more often associated with:
  • Specific formulations or polymorphs
  • Manufacturing methods
  • Use-related claims

Market impact

• If no enforceable patents remain, generic approvals and switching tend to progress quickly.
• If there are late-expiring patents tied to formulation or processes, the brand can temporarily retain share despite active ingredient patent expiry.

How do paragraph IV challenges and settlements shape earnings for legacy antibiotic brands?

When a branded erythromycin product still has enforceable formulation or process patents, its financial risk can rise around:

• Paragraph IV ANDA filings
• District court litigation
• Potential 30-month stay expirations
• Settlement agreements that can delay or license generic entry

Typical financial impact

• Litigation period is associated with heightened uncertainty and potential short-run gross-to-net volatility.
• Settlement outcomes can shift the timing of price erosion.

For most legacy antibiotics, however, the dominant driver remains the already-established generic ecosystem, so earnings sensitivity is usually less about brand-new exclusivity fights and more about ongoing reimbursement and contract dynamics.

How does ERYTHROCIN STEARATE compare with azithromycin and clarithromycin in market traction?

Relative demand generation

• Azithromycin generally captures broader outpatient volume due to dosing convenience and clinician preference.
• Clarithromycin can maintain share in certain clinical workflows.
• Erythromycin products typically hold narrower niches and face higher substitution rates.

Relative financial posture

• Newer macrolide brands tend to show greater pricing resilience early in lifecycle; older erythromycin brands show persistent revenue dilution after generic saturation.
• For ERYTHROCIN STEARATE, the most likely financial signature is gradual brand erosion rather than cyclical growth.

What manufacturing and IP barriers influence cost of goods and margin stability?

For legacy oral antibiotics:

• Cost of goods stability depends on API sourcing and batch yield.
• Manufacturing disruptions can create short-lived price increases or supply pulls.
• IP barriers are usually limited unless the product has formulation-specific or process-specific claims that remain active.

Margin implications

• As generics expand, branded gross margin is pressured by net price compression.
• Channel rebates and competitive pricing can reduce operating margin even if unit volume is stable.

What commercial channels drive ERYTHROCIN STEARATE revenue (retail vs institutional)?

Retail

• Highly competitive substitution environment.
• Brand retention depends on:
  • Prescriber habits
  • Patient history
  • Pharmacy purchasing preferences

Institutional

• Tender and contracting often determine which products are stocked.
• Erythromycin may persist where specific institutional protocols reference it.

Financially, institutional channel switches can create discrete quarter-to-quarter revenue changes due to award timing.

Key Takeaways

• ERYTHROCIN STEARATE’s market dynamics are dominated by structural generic substitution and antibiotic stewardship-driven prescribing limits.
• Financial trajectory is expected to show branded revenue erosion driven by net price compression and formulary status changes, with limited growth catalysts.
• Competitive pressure from azithromycin and clarithromycin primarily reduces default macrolide selection and sustains a niche positioning for erythromycin stearate.
• Earnings sensitivity typically comes more from reimbursement and contracting than from major demand expansion.

FAQs

1. Why does ERYTHROCIN STEARATE lose market share faster than unit prescriptions?
2. What formulary levers most influence ERYTHROCIN STEARATE retention in hospitals?
3. How do macrolide antibiograms shift prescribing away from erythromycin in key regions?
4. What pricing swings occur when a new multi-source generic enters erythromycin salt categories?
5. Does ERYTHROCIN STEARATE have greater demand stability in institutional contracts than in retail?

References

1. FDA Orange Book. U.S. Food and Drug Administration.
2. FDA Drug Shortages. U.S. Food and Drug Administration.
3. CDC Antibiotic Stewardship Resources. Centers for Disease Control and Prevention.