Drugs in MeSH Category Anti-Ulcer Agents

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Exclusivity Expiration
Lannett Co Inc	RABEPRAZOLE SODIUM	rabeprazole sodium	TABLET, DELAYED RELEASE;ORAL	090678-001	Nov 8, 2013	AB	RX	No	No
Teva	FAMOTIDINE	famotidine	TABLET;ORAL	075311-001	Apr 16, 2001		DISCN	No	No
Mylan	LANSOPRAZOLE	lansoprazole	CAPSULE, DELAYED REL PELLETS;ORAL	203187-001	Jun 1, 2016		DISCN	No	No

Market dynamics and patent landscape for Anti-Ulcer Agents (NLM MeSH): exclusivity timelines, Orange Book status, and generic entry risk

Last updated: June 25, 2026

Anti-ulcer agents remain a high-volume, low-cost category where pricing pressure and “evergreening” via formulation and method patents dominate enforcement strategy. Patent estates in this MeSH class tend to be fragmented across (1) reference drugs with staggered exclusivities, (2) line extensions (dose forms, strengths, salts, and delivery systems), and (3) device-adjacent or combination patents where relevant (for example, fixed-dose H. pylori regimens). Generic and biosimilar risk is generally front-loaded for oral small molecules; the main residual risk is product-specific and paragraph IV-dependent (ANDA for small molecules). The compliance outcome is typically determined by Orange Book list-level granularity: which patents are listed for a specific NDA/BLA and whether FDA-approved generics can “design around” at the listed-claim scope.

This report maps market dynamics and the patent logic that drives entry timing across the Anti-Ulcer Agents class, with a focus on U.S. regulatory mechanics (Orange Book, 180-day exclusivity, forfeiture triggers), patent expiration patterns, and common litigation and settlement structures.

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Which Anti-Ulcer Agents drive the patent and market cycle in the U.S.?

Short answer: Proton pump inhibitors and related acid-suppression products dominate both volume and IP filings. H2-receptor antagonists and mucosal agents are smaller in spend, but they can still generate long tail value through formulation patents tied to specific strengths and release profiles.

Core sub-classes within MeSH “Anti-Ulcer Agents”

The MeSH umbrella includes multiple therapeutic families used for peptic ulcer disease, GERD, gastritis, and related dyspepsia syndromes:

• Proton pump inhibitors (PPIs): omeprazole, lansoprazole, pantoprazole, rabeprazole, esomeprazole (and related salts)
• H2-receptor antagonists: famotidine, cimetidine, nizatidine
• Mucosal protective agents and anti-ulcer adjuncts: sucralfate, bismuth compounds, misoprostol (in relevant indications)
• Combination or regimen products used in H. pylori eradication strategies where applicable (class-dependent)

Market dynamics that shape IP behavior

• Patent clustering around controlled release and specific strengths. Even when the active ingredient patent expires, brand-sponsored “listed” patents often cover enteric coating characteristics, delayed-release behavior, or specific formulation components that support label claims.
• Switching effects and “therapeutic interchangeability.” Formularies and PBMs drive rapid substitution once ANDA entry is acceptable. This pushes brand companies toward settlements that delay generic triggers rather than sustaining long-term pricing via differentiation.
• Regulatory and labeling constraints define what can be substituted. For example, GERD maintenance dosing schedules and pediatric or complicated ulcer labels can slow certain switches even after active-ingredient expiry.

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How do Anti-Ulcer Agents patent estates typically expire in the U.S.?

Short answer: The category usually shows a two-stage IP unwind: (1) active-ingredient and core process patents expire, then (2) formulation and method-of-use patents listed in the Orange Book determine the remaining barriers to ANDA approval.

Typical expiration and “listed patent” structure

For U.S. small-molecule anti-ulcer agents, brand-controlled exclusivity and patent coverage generally follows:

• Active ingredient composition-of-matter (CoM) patents: earliest pillar, often expiring first.
• Process and purification patents: can extend secondary coverage but are frequently harder to assert against generic manufacturing unless claim scope reads on the commercial process.
• Formulation patents: frequently cover specific delayed-release or enteric-coating performance, tablet/capsule design, and stability.
• Method-of-use patents: cover dosing regimens, titration schedules, or patient subpopulations tied to label claims.
• Pediatric exclusivity / regulatory exclusivity: can operate alongside patent expiration and is mechanism-dependent.

Orange Book “listed” patents are the gating item

ANDA approval must address each relevant Orange Book listed patent for the proposed drug product. When multiple patents are listed, brands can leverage parallel litigation to maintain leverage beyond the first expiry.

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When do Anti-Ulcer Agents lose exclusivity, and how does FDA approval timing affect generic entry?

Short answer: Generic entry timing is driven by the later of (a) patent expiration for the listed patents asserted, (b) 180-day exclusivity status, and (c) Orange Book listing validity or design-around success.

Exclusivity levers that matter most

• 180-day exclusivity for the first paragraph IV filer. If another filer wins forfeiture or if the first filer fails to meet approval/marketing triggers, the exclusivity can become irrelevant.
• Patent term adjustment and extension effects. These can shift expiration dates and create litigation windows that straddle ANDA filing schedules.
• Staggered ANDA approvals. Even when an active ingredient is off-patent, product-specific strengths and dosage forms can remain blocked by different listed patents.

Featured snippet: generic entry logic

Generic timelines typically follow:

1. ANDA filing with paragraph IV to Orange Book patents
2. Patent litigation automatic stay (if triggered within statutory windows)
3. Post-stay approval if patents expire or are found invalid/not infringed
4. Potential re-entry sequencing by 180-day exclusivity and “first-to-market” status

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Which patents protect Anti-Ulcer Agents formulations, and why do they matter for design-around?

Short answer: Brand formulation patents most often cover delayed-release/enteric-coating compositions and process parameters that preserve acid-labile drug integrity, and they are the dominant “last-mile” barrier after CoM expiry.

Formulation claim patterns seen in anti-ulcer products

Common claim themes include:

• Enteric coating polymer blends and thickness ranges
• Dissolution and disintegration specifications (in simulated gastric fluid vs. intestinal fluid)
• Stabilizers, anti-migration agents, and impurity limits
• Release profiles for once-daily and twice-daily regimens
• Specific granulation or coating process steps linked to performance

Why design-around often fails on paper and succeeds in practice

• Performance testing is hard to replicate. Even with different polymers, generic developers must meet dissolution and bioequivalence while avoiding claim coverage.
• Method-of-use vs. formulation overlap. If a brand’s method patents reference a specific release profile or regimen, formulation changes can indirectly affect infringement.

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What patent litigation affects Anti-Ulcer Agents, and what are the most common settlement structures?

Short answer: Litigation tends to center on Orange Book listed patents and claim-level infringement defenses. Settlements frequently resolve into (1) delayed launch windows by strength/form, (2) “carve-out” licenses that allow entry for certain dosage forms, or (3) consent decrees that set design parameters.

Settlement mechanics that shape market entry

• Staggered launch by strength. Companies often agree that the generic will enter specific strengths first, leaving other strengths delayed.
• Design-around concessions. Settlement terms can require the generic to avoid certain formulation approaches to reduce risk of further suit.
• Non-marketing covenants and triggers. Some agreements link launch to patent expiration for specified patents, not a single date.

Litigation tempo and commercial leverage

Brands often maintain pressure by:

• asserting multiple listed patents in parallel
• focusing infringement theories on formulation performance and manufacturing steps
• using discovery schedules to keep the generic team from finalizing launch readiness

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What is the Orange Book status of Anti-Ulcer Agents, and how does that control ANDA risk?

Short answer: Orange Book listing status determines whether ANDA sponsors must litigate, wait out expirations, or negotiate licenses. The list is the operational map for infringement and stay risk.

Operational implications for generic strategy

For each NDA product in this class, risk depends on:

• whether patents are “listed” for that specific drug product (not the active ingredient alone)
• whether the listed patents are for formulation, method, or manufacturing
• whether the ANDA sponsor filed the first paragraph IV challenge (180-day exclusivity)
• whether litigation is resolved by invalidity, non-infringement, or settlement

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How does MeSH “Anti-Ulcer Agents” compare with neighboring MeSH classes on patent durability?

Short answer: Anti-ulcer agents have relatively mature small-molecule markets where the durability of IP is mainly product-line and formulation-driven rather than platform-driven.

Comparison: where durability comes from

• Anti-ulcer agents vs. broader GI therapies: Anti-ulcer IP often peaks around PPIs and their line extensions.
• Anti-ulcer agents vs. oncology and biologics: the latter can have platform-level patent networks; anti-ulcer estates are generally narrower but more numerous through formulation tailoring.

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Which companies are challenging Anti-Ulcer Agent patents via ANDA paragraph IV certifications?

Short answer: Generic challengers typically include major ANDA filers and label-presence players. In practice, the contest is product-specific and strength-specific, because litigation risk tracks Orange Book listings.

Commercial pattern

• Multiple ANDA sponsors can challenge the same reference product.
• Only one receives (or retains) 180-day exclusivity, which changes market leverage in the settlement posture.
• Subsequent challengers time launch to remaining patents or to the settlement outcomes affecting the first-filer’s exclusivity.

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What generic entry risks exist for Anti-Ulcer Agents after patent expiration?

Short answer: Entry risk remains for generic sponsors on two fronts: (1) remaining listed patents that expire later than the active ingredient, and (2) settlement constraints that cap design or launch timing even after nominal patent expiry.

Residual barriers

• Late-expiring formulation patents that are not automatically swept by CoM expiry.
• Method-of-use claims that can remain asserted for label-congruent regimens.
• Re-listing events or updates to Orange Book lists that introduce additional listed patents on the same product.

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What is the FDA regulatory status pattern for Anti-Ulcer Agents, and how does pathway choice affect exclusivity?

Short answer: Anti-ulcer agents are predominantly approved as small-molecule NDAs with ANDA generics. Regulatory pathway choice affects when exclusivity protection or forfeiture becomes relevant, but the core timing still tracks Orange Book listed patents.

Mechanism checklist

• Reference product exclusivity (if any) is label and regulatory-event dependent.
• ANDA approval pathway is patent-list driven.
• Pediatric exclusivity and market exclusivity are distinct from patent term and can extend the operational barrier.

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How strong is the patent estate for Anti-Ulcer Agents overall?

Short answer: Strength is “moderate but fragmented.” Many active ingredients are near or beyond CoM expiration, but enforcement remains viable through listed formulation and method patents that can be asserted product-by-product.

Practical strength scoring framework (category-level)

A useful operational view:

• High strength: multiple listed patents per NDA product with consistent claim coverage over dosage form and release profile
• Medium strength: fewer listed patents but with broad formulation or method claims
• Low strength: expired CoM with limited remaining listed patents or narrow claims that are easy to design around

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Key tables: how to map Anti-Ulcer Agents patent risk by product and listing

Because “Anti-Ulcer Agents” is a broad MeSH umbrella, risk must be measured at the level of specific reference products and their Orange Book listed patents. The tables below provide a template aligned to how ANDA litigation risk is actually priced.

Table 1. Patent-and-exclusivity risk map (per NDA product)

Product (active ingredient)	Dosage form/strength	Orange Book listed patents present?	Main patent type (typical)	Expected bottleneck	Generic launch sensitivity
PPI (example)	DR capsule	Yes	formulation + method	end-to-end dissolution/release + regimen	High
H2 blocker (example)	tablet	Yes/limited	method or formulation	specific strength design	Medium
Mucosal agent (example)	suspension/tablet	Case-dependent	formulation/manufacturing	performance and impurities	Medium

Table 2. Litigation and settlement levers (per challenged patent)

Litigation event	What it changes	Commercial impact
Paragraph IV + timely suit	triggers automatic stay	delays ANDA approval until resolution
180-day exclusivity allocation	affects first-filer launch	shifts market share capture
Settlement agreement	defines launch date/design constraints	can extend delays beyond statutory expiry
Court ruling (invalidity/non-infringement)	clears specific patents	accelerates approval for all compliant ANDAs

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Key Takeaways

1. Anti-ulcer agents are a mature small-molecule market where patent durability mainly comes from Orange Book-listed formulation and method patents, not the primary CoM estate.
2. Generic entry timing is governed by listed patents per NDA product, 180-day exclusivity status, and settlement constraints, not by active ingredient expiry alone.
3. The most actionable diligence is “per drug product, per strength, per Orange Book list,” because the category-level label hides product-specific legal exposure.
4. Litigation strategy and settlement outcomes typically hinge on paragraph IV timing and the scope of formulation/release and regimen claims.

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FAQs

1. How do Orange Book patent listings for specific strengths affect ANDA approval for anti-ulcer drug generics?
2. What does 180-day exclusivity mean for the first paragraph IV filer in anti-ulcer agent cases, and when does it get forfeited?
3. Which anti-ulcer agent patents are most frequently “design-around” targets: formulation, method-of-use, or manufacturing process claims?
4. How do settlement agreements in anti-ulcer agent patent cases typically structure delayed generic launch dates across strengths?
5. What regulatory exclusivity events (pediatric or other) can extend market barriers for anti-ulcer agents after patent expiration?

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References

1. Food and Drug Administration. Orange Book: Approved Drug Products with Therapeutic Equivalence Evaluations. U.S. FDA.
2. U.S. Code. 35 U.S.C. § 271(e) and related Hatch-Waxman provisions (automatic stay and paragraph IV framework).
3. National Library of Medicine. Medical Subject Headings (MeSH): Anti-Ulcer Agents.