US Patent 4,066,755 Landscape and Claim Scope for Hypertension Treatment Using 5-[1-hydroxy-2-(1-methyl-3-phenylpropyl)aminoethyl]salicylamide
US Drug Patent 4,066,755 is a composition-and-method patent centered on a single active ingredient, 5-[1-hydroxy-2-(1-methyl-3-phenylpropyl)aminoethyl]salicylamide (and its physiologically acceptable acid addition salts), for hypertension. The independent claim scope is relatively narrow on the identity of the active ingredient and broad on formulation/carrier and administration routes (oral, suppository, injection). The asserted therapeutic mechanism in the method claim is a functional dual-blocker requirement: blocking both α- and β-adrenergic receptors.
Because this patent is specifically claim-anchored to a defined chemical entity and its salts, the practical landscape for competitors turns on (1) whether they use the same compound (or a covered salt), (2) whether they land inside dosage-unit ranges (primarily for dependent claims), and (3) whether their clinical claims or labeling tie to hypertension via the claimed dual α/β blockade.
What does US Patent 4,066,755 claim protect: the active ingredient, salts, dosage forms, or methods?
Core answer: It protects (a) pharmaceutical compositions containing the defined active ingredient or its physiologically acceptable acid addition salts with a non-toxic carrier, and (b) methods of treating hypertension using that compound, characterized by dual α- and β-adrenergic receptor blocking.
Claim 1: independent composition claim (active-ingredient identity + carrier)
- Claim type: Composition of matter (pharmaceutical composition).
- Active ingredient requirement: “effective amount of
5-[1-hydroxy-2-(1-methyl-3-phenylpropyl)aminoethyl]salicylamide or a physiologically acceptable acid addition salt thereof.”
- Form: “in association with a non-toxic pharmaceutically acceptable carrier.”
Scope implications
- Literal infringement requires the accused product to contain the same chemical entity (or a covered physiologically acceptable acid addition salt).
- The carrier is essentially conventional. The carrier language is broad and rarely limits infringement.
- The “effective amount” language supports infringement even if the strength varies, unless explicitly constrained by dependent dosage claims.
Claims 2–3: narrower composition claims (specific free base vs HCl salt)
- Claim 2: active ingredient is the free base.
- Claim 3: active ingredient is the hydrochloride salt.
Scope implications
- These are fallback positions. If a competitor markets a salt different from HCl (but still an acid addition salt), Claim 1 may still read on it; Claim 3 would not.
- If a competitor uses the HCl salt, both Claim 1 and Claim 3 are implicated (depending on how “physiologically acceptable acid addition salt” is interpreted in the record).
Claims 4–6: dosage-unit and dosage form limitations
- Claim 4: dosage unit contains 5 mg to 1000 mg of the active ingredient.
- Claim 5: dosage unit contains 20 mg to 200 mg.
- Claim 6: composition in tablet form.
Scope implications
- These depend on Claim 1 and are strength and dosage-form limited.
- A competitor could still infringe Claim 1 while avoiding Claims 4–6 by using different unit strengths or dosage forms (unless those variations still fall under Claim 1 as a “composition” without the dependent constraints).
Claims 7–10: independent method claim + dependent route/form/strength limitations
- Claim 7 (method, independent): treat human hypertension by administering orally, by suppository, or by injection an effective amount of the compound, characterized by blocking both α- and β-adrenergic receptors.
- Claim 8: oral administration.
- Claim 9: tablet form.
- Claim 10: each tablet contains 20 mg to 200 mg.
Scope implications
- The dual receptor blockade is a functional limitation. In litigation, parties typically contest whether the accused compound exhibits the claimed pharmacology under relevant conditions and concentrations.
- The route flexibility in Claim 7 is meaningful. Even if a product avoids oral tablets, it could still infringe through suppository or injection if it uses the covered compound/salt.
- Dependent claims narrow to oral and tablet formats and the 20–200 mg strength band.
What is the practical infringement scope: if a company makes a generic, will it fall inside Claims 1–10?
Core answer: A product containing the same defined active ingredient (or a physiologically acceptable acid addition salt) for hypertension is the main risk. Avoidance strategies usually focus on changing the active ingredient, changing the salt outside the claimed “physiologically acceptable acid addition salt” set, or changing dosage-unit strength and dosage form to avoid dependent claims. The method claim also ties to a dual α/β blockade characterization.
Infringement scenarios by product type
| Scenario |
Likely implicated claims |
Key technical lever |
| Generic uses same free base compound at any strength |
Claim 1 and method Claim 7 (if marketed/used for hypertension via dual α/β blockade) |
Presence of exact active ingredient in a pharmaceutically acceptable composition |
| Generic uses the HCl salt |
Claims 1, 2 (if free base not used), and 3; dependent strength/form claims if matched |
Whether the product is specifically the hydrochloride |
| Generic uses a different acid addition salt (e.g., another pharmaceutically acceptable salt) |
Claim 1 (and method Claim 7) |
Whether the salt is “physiologically acceptable” under claim construction |
| Generic uses tablets but with tablet strength outside 20–200 mg |
Claim 1 and possibly Claim 7 |
Avoid Claim 5/6/9/10 while still reading on Claim 1/7 |
| Product is oral solution/inhalation rather than oral tablet |
Claim 1 and method Claim 7 |
Dependent tablet claims (9) and strength bands (10) can be avoided |
| Product is suppository or injection (tablet-free) |
Claim 1 and method Claim 7 |
Dependent Claim 8/9/10 avoided; Claim 7 remains |
| Product treats hypertension with a different drug but marketed as “dual α/β blocker” |
Typically not covered by these claims |
Claim identity limitation to the defined salicylamide compound |
What formulations are protected by US 4,066,755: tablets, suppositories, injections, and carriers?
Core answer: The patent is not formulation-platform specific. It covers the active ingredient in “association with a non-toxic pharmaceutically acceptable carrier” (Claim 1) and explicitly supports multiple administration routes in the method claim: oral, suppository, injection (Claim 7). Tablets are singled out in dependent composition and method claims.
Formulation breadth in Claim 1
- Carrier is open-ended: “non-toxic pharmaceutically acceptable carrier.”
- This typically covers common excipients for oral solid dosage forms, as well as vehicles for other routes, depending on how the formulation is embodied.
Route specificity only appears in the method claim
- Claim 7 includes oral, suppository, and injection administration.
- Dependent Claim 8 and Claim 9 narrow to oral and tablet.
Strength band protection
- Dependent claims constrain the dosage unit (20–200 mg band) and the tablet strength (20–200 mg per tablet).
What method-of-use scope exists: does the patent cover hypertension treatment by dual α/β adrenergic blockade only?
Core answer: Yes. Claim 7’s method is characterized by the pharmacological function “blocking both α- and β-adrenergic receptors.” That functional limitation drives whether a hypertension use is within the patent’s scope for a given compound.
Method claim structure
- Disease target: “human patient suffering from hypertension.”
- Administration: “orally, by suppository or by injection.”
- Drug identity: the defined salicylamide or physiologically acceptable acid addition salt.
- Functional characterization: compound is “having both α- and β-blocking activity.”
How that typically plays in disputes
- Product identity fights: whether the accused drug is the same compound/salt.
- Pharmacology fights: whether the accused compound has both α and β blocking activity sufficient to satisfy the functional characterization.
How strong is the patent estate for this compound: is US 4,066,755 likely the key anchor patent or one of many?
Core answer: Based on claim drafting, US 4,066,755 is positioned as a primary anchor because it directly claims the active ingredient in compositions and the hypertension treatment method. In most estates like this, later patents usually add formulation-specific, salt-specific, process, or new salt polymorph angles. But the claim set you provided contains only composition and method language, with no explicit manufacturing process or polymorph constraints.
Estate inference from claim scope
- If a later entrant uses the same active ingredient (free base or an “acid addition salt”), US 4,066,755 is likely to be directly relevant.
- If they switch to a different chemical entity, the estate must rely on other patents, not US 4,066,755.
(You did not provide bibliographic identifiers like assignee, priority dates, or related patents; therefore this analysis stays focused on scope from the claims.)
When does US 4,066,755 lose exclusivity: expiration drivers for compound and method claims
Core answer: Expiration depends on the patent’s legal term under US law and any adjustments or extensions. This analysis cannot compute an exclusivity end date from the claim text alone.
What is the Orange Book status of US 4,066,755 for hypertension products?
Core answer: Orange Book listing status cannot be determined from the claim text provided. Orange Book requires application-level linkage to drug products and patents.
Which companies are challenging US 4,066,755 via Paragraph IV or other FDA filings?
Core answer: Company-by-company challenge activity cannot be determined from the claims text alone. Paragraph IV depends on Orange Book listings and specific generic ANDA certifications.
What generic entry risks exist for products using 5-[1-hydroxy-2-(1-methyl-3-phenylpropyl)aminoethyl]salicylamide?
Core answer: The generic entry risk is highest for ANDA products whose labeled use and composition match the claimed active ingredient (or covered acid addition salts), and whose dosage form and unit strength do not fall outside dependent claim constraints if asserted as a composition or method.
Risk matrix by product design
| Design choice |
Risk to Claim 1 / Claim 7 |
Risk to dependent claims (4-6, 8-10) |
| Same active ingredient |
High |
Strength/form dependent risk depends on unit specs |
| Same salt but different unit strengths |
High |
Reduced for 20–200 mg dependent claims |
| Different route (e.g., injection/suppository) |
High |
Avoids tablet-specific dependent method claims |
| Different dosage form for composition only |
Depends |
Avoids tablet-dependent claims |
| Different chemical entity |
Low vs US 4,066,755 |
None from identity limitation |
How does US 4,066,755 compare with typical α/β blocker patent patterns?
Core answer: Unlike many α/β blockers where claims broaden around pharmacology, dosing regimens, or combinations, US 4,066,755 is rigid around a specific salicylamide chemical identity. The breadth comes from:
- open-ended carrier language, and
- multi-route administration in the method claim,
while the limitation comes from:
- exact active ingredient identity (and acid addition salts),
- functional dual α/β blockade characterization.
Key takeaways
- US 4,066,755 protects hypertension therapies built around 5-[1-hydroxy-2-(1-methyl-3-phenylpropyl)aminoethyl]salicylamide (and physiologically acceptable acid addition salts).
- Independent protection is split between:
- Composition (Claim 1) with a non-toxic carrier, and
- Method of treating hypertension (Claim 7) requiring dual α- and β-adrenergic receptor blocking.
- Dependent claims narrow to:
- hydrochloride salt (Claim 3),
- tablet form (Claim 6),
- 20–200 mg unit strength and tablet strength band (Claims 5 and 10),
- oral-only route for the method (Claim 8) and oral tablets (Claim 9).
- Competitive risk is driven primarily by active-ingredient identity (and salt coverage); secondary risk follows dosage unit strength and dosage form.
FAQs
1) Does US 4,066,755 cover both the free base and hydrochloride salt?
Yes. Claim 1 covers the compound and physiologically acceptable acid addition salts; Claims 2 and 3 specifically distinguish the free base and the hydrochloride.
2) Can a product avoid infringement by changing tablet strength from 20–200 mg to another range?
It can reduce exposure to dependent strength claims (Claims 5 and 10), but it does not avoid Claim 1 (composition) or Claim 7 (method) if the active ingredient and salt and intended hypertension use remain within scope.
3) Is tablet form required for the method claim?
No. Claim 7 includes oral, suppository, or injection. Tablet is required only in dependent Claims 9 and 10.
4) If a competitor uses a different salt than hydrochloride, does the patent still apply?
Claim 1 can still apply if the alternative salt is a physiologically acceptable acid addition salt. Claim 3 would not apply if the product is not the hydrochloride.
5) What is the key pharmacology limitation in the method claim?
Claim 7 requires a compound “having both α- and β-blocking activity” used to treat hypertension.
References
(No sources were cited because the request provided only claim text and did not include patent bibliographic records, Orange Book identifiers, litigation dockets, FDA labels, or other documentary inputs.)
