Last Updated: June 12, 2026

dextromethorphan polistirex - Profile


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What are the generic drug sources for dextromethorphan polistirex and what is the scope of patent protection?

Dextromethorphan polistirex is the generic ingredient in two branded drugs marketed by Rb Hlth, Amneal, Aurobindo Pharma Ltd, and Tris Pharma Inc, and is included in four NDAs. Additional information is available in the individual branded drug profile pages.

Summary for dextromethorphan polistirex
US Patents:0
Tradenames:2
Applicants:4
NDAs:4
Paragraph IV (Patent) Challenges for DEXTROMETHORPHAN POLISTIREX
Tradename Dosage Ingredient Strength NDA ANDAs Submitted Submissiondate
DELSYM Extended-release Suspension dextromethorphan polistirex 30 mg/5 mL 018658 1 2009-01-12

US Patents and Regulatory Information for dextromethorphan polistirex

Applicant Tradename Generic Name Dosage NDA Approval Date TE Type RLD RS Patent No. Patent Expiration Product Substance Delist Req. Exclusivity Expiration
Rb Hlth DELSYM dextromethorphan polistirex SUSPENSION, EXTENDED RELEASE;ORAL 018658-001 Oct 8, 1982 OTC Yes Yes ⤷  Start Trial ⤷  Start Trial ⤷  Start Trial
Amneal DEXTROMETHORPHAN POLISTIREX dextromethorphan polistirex SUSPENSION, EXTENDED RELEASE;ORAL 203133-001 Jul 28, 2017 OTC No No ⤷  Start Trial ⤷  Start Trial ⤷  Start Trial
Aurobindo Pharma Ltd DEXTROMETHORPHAN POLISTIREX dextromethorphan polistirex SUSPENSION, EXTENDED RELEASE;ORAL 218417-001 Apr 15, 2026 OTC No No ⤷  Start Trial ⤷  Start Trial ⤷  Start Trial
>Applicant >Tradename >Generic Name >Dosage >NDA >Approval Date >TE >Type >RLD >RS >Patent No. >Patent Expiration >Product >Substance >Delist Req. >Exclusivity Expiration

Expired US Patents for dextromethorphan polistirex

Applicant Tradename Generic Name Dosage NDA Approval Date Patent No. Patent Expiration
Rb Hlth DELSYM dextromethorphan polistirex SUSPENSION, EXTENDED RELEASE;ORAL 018658-001 Oct 8, 1982 4,221,778 ⤷  Start Trial
Rb Hlth DELSYM dextromethorphan polistirex SUSPENSION, EXTENDED RELEASE;ORAL 018658-001 Oct 8, 1982 5,980,882 ⤷  Start Trial
>Applicant >Tradename >Generic Name >Dosage >NDA >Approval Date >Patent No. >Patent Expiration

Investment Scenario and Fundamentals Analysis: Dextromethorphan Polistirex

Last updated: April 24, 2026

What is dextromethorphan polistirex in the market?

Dextromethorphan polistirex is an oral, extended-release formulation of the antitussive dextromethorphan designed to suppress cough. It is marketed in multiple countries under brand and generic labels, typically positioned for symptomatic treatment of cough associated with colds and other upper respiratory conditions.

What is the patent and exclusivity landscape for dextromethorphan polistirex?

U.S. patent and exclusivity reality

Dextromethorphan (free base) is an older active ingredient. Dextromethorphan polistirex refers to a specific extended-release formulation technology (polistirex matrix), and IP value typically lives in:

  • formulation and manufacturing process claims
  • specific dosage form, excipient system, and release profile
  • related method-of-use claims (often limited for OTC antitussives)

Result: In most real-world portfolio models, the active ingredient and the therapeutic use are not protected in the way that modern branded small-molecule NCEs are. Value concentrates in late-stage reformulations or specific product-specific IP, which generally has a shorter monetization window than classic blockbusters.

Data needed to complete a precise, investment-grade patent map

A complete, exact patent-and-expiration table requires product-level identifiers (reference listed drug, NDA/BLA numbers, Orange Book entries, and specific granted US patents for “polistirex” formulations). Without those, producing a correct expiration forecast would be speculative.

How do fundamentals look at the product level (demand, pricing power, and competition)?

Demand drivers

  • Epidemiology: Upper respiratory infections drive episodic demand. Dextromethorphan antitussives are used symptomatically and are seasonal.
  • OTC and formulary behavior: Many antitussives in this class are OTC or have OTC-adjacent dynamics, which compresses pricing power.
  • Substitution: Generic entry usually forces price convergence unless the brand differentiates on perceived onset/duration or a distinct release profile that is hard to replicate.

Pricing power and margins

  • Extended-release formats can hold a modest price premium versus immediate-release where reimbursement or consumer preference supports it.
  • In the OTC environment, margins are constrained by:
    • shelf competition
    • pharmacy and distributor contract pricing
    • private label pressure
    • frequent SKU churn in cough and cold categories

Competitive set

For investors, the relevant competitive set is not “other polistirex-only products.” It is the broader antitussive category:

  • immediate-release dextromethorphan products
  • other antitussive classes (where marketed)
  • combination cough/cold products that reduce pure antitussive share

Implication: dextromethorphan polistirex fundamentals are mainly product execution and distribution, not durable clinical differentiation.

What is the risk profile (regulatory, litigation, and supply)?

Regulatory risk

  • Dextromethorphan antitussives are established drug substances with well-known safety and manufacturing expectations.
  • For formulation-based products, regulatory risk tends to cluster around:
    • bioequivalence and release characterization
    • stability of the polymer matrix system
    • manufacturing scale-up consistency

Litigation risk

  • Patent disputes in this space tend to be formulation-specific and fact-dependent.
  • The most common litigation path is “generic formulation challenges” tied to:
    • release mechanism or dissolution profile equivalence
    • manufacturing process
    • alleged infringement of formulation claims

Supply and execution risk

  • Polymer-matrix extended-release products can face:
    • sourcing stability for excipients
    • process tuning for particle size, viscosity, and release kinetics
    • batch-to-batch release variability during scale-up

What does a realistic investment thesis look like?

Thesis A: Distribution and SKU economics (low patent durability)

Core bet: unit volumes and gross margin stability driven by channel execution and seasonal demand capture.

  • Upside levers:
    • expand retailer and pharmacy placement
    • maintain extended-release perception versus immediate-release SKUs
    • rationalize pack sizes and pricing ladders in peak cough season
  • Downside levers:
    • generic or private label pressure
    • retailer switching to cheaper equivalents

Fit: smaller manufacturers and branded OTC operators with strong distribution.

Thesis B: Product line extension (formulation IP as the main asset)

Core bet: build additional product-specific IP around release control, stability, or combination products.

  • Upside levers:
    • defend formulation-specific claims
    • create a next-gen matrix with better release consistency or lower dose burden
  • Downside levers:
    • rapid generic replication if the formulation moat is thin
    • regulatory pathways that shorten exclusivity

Fit: companies with formulation development capability and disciplined IP prosecution.

Thesis C: Licensing or acquisition of market share (asset-light strategy)

Core bet: acquire/partner to capture an existing OTC footprint.

  • Upside levers:
    • immediate channel access
    • avoid early development timelines
  • Downside levers:
    • limited patent-driven leverage
    • dependence on marketing and slotting costs

Fit: investors targeting cash-flow rather than long-duration exclusivity.

What are the key due-diligence checks before underwriting?

1) Product identity mapping

Investment underwriting should start with:

  • exact marketed form (brand, strength, extended-release characteristics)
  • active content confirmation (dextromethorphan polistirex salt/formulation)
  • the reference product for bioequivalence if generics exist

2) Competitive intensity and price history

  • track retail and wholesale price levels by SKU and strength
  • measure share erosion since the first generic launch
  • monitor new entrants that use alternative extended-release technologies

3) Patent and regulatory status at the NDA/product level

Even if the active ingredient is old, the formulation’s specific exclusivity matters for:

  • product-specific patents
  • any regulatory exclusivity attached to the specific product approval (where applicable)
  • any market exclusivity periods linked to specific applications

4) Manufacturing and quality system strength

  • assess batch release controls linked to extended-release performance
  • evaluate stability and polymer matrix behavior across shelf-life

What are the likely market dynamics over a 3-to-5-year horizon?

  • Seasonal volume growth is likely modest and driven by respiratory-season intensity, not by innovation.
  • Real price trajectories should trend toward normalization if generic competition is present.
  • Brand differentiation will be limited to patient-perceived duration and consumer preference rather than clinical superiority.
  • Any upside is most likely tied to execution: distribution, inventory management for seasonal peaks, and pack-format optimization.

Key takeaways

  • Dextromethorphan polistirex is an established antitussive extended-release formulation where fundamentals are driven by OTC/SKU economics, not durable clinical differentiation.
  • Investment upside typically comes from distribution, brand execution, and formulation-specific product economics, not long-lived patent cliffs.
  • For an accurate patent and expiration underwriting, the analysis must be built from product-level IP entries tied to the specific marketed extended-release formulation; generic timelines for the active ingredient alone do not capture the formulation moat.
  • The underwriting risk is dominated by substitution and pricing pressure, with regulatory risk centered on extended-release performance and manufacturing consistency.

FAQs

1) Is dextromethorphan polistirex protected like a new chemical entity?
No. Value generally relies on product-specific formulation and any remaining patent coverage tied to the exact dosage form, not NCE-style global exclusivity.

2) What drives demand for this product?
Seasonal upper-respiratory infection incidence and OTC consumer purchasing for symptomatic cough relief.

3) Where does pricing power come from?
From perceived duration and brand distribution strength versus immediate-release and private label alternatives.

4) What is the main competitive threat?
Generic substitution and private label cough products that reduce share through price and assortment.

5) What is the most important underwriting diligence item?
Mapping the exact marketed product to the correct product-level patent and regulatory status, then validating it against observed market share and price erosion.


References

[1] U.S. Food and Drug Administration. Orange Book: Approved Drug Products with Therapeutic Equivalence Evaluations. FDA. https://www.accessdata.fda.gov/scripts/cder/daf/
[2] PubChem. Dextromethorphan Polistirex. National Library of Medicine. https://pubchem.ncbi.nlm.nih.gov/

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