Details for Patent: 3,888,995
Summary for Patent: 3,888,995
| Title: | Fatty alcohol-propylene glycol vehicle | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Abstract: | A substantially non-aqueous medicant vehicle containing from 15 to 45 parts saturated fatty alcohol having from 16 to 24 carbons, from 45 to 85 parts glycol solvent, from 0 to 15 parts plasticizer, from 0 to 15 parts coupling agent, 0 to 20 parts penetrant, and if desired, other pharmaceutical adjuvants. This base is a suitable vehicle for all types of therapeutic agents for topical application including antibiotics, steroids, antihistamines, antiseptics, anesthetics, antibacterials, fungicides, and the like. The vehicle has shown particular advantages with anti-inflammatory topical corticoids. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Inventor(s): | Martin Katz, Herbert M Neiman | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Assignee: | Roche Palo Alto LLC | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Application Number: | US120691A | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Patent Claim Types: see list of patent claims | Use; Composition; Compound; | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Patent landscape, scope, and claims: | # United States Patent 3,888,995: Claim Scope, Expiration, Enforceability and Topical-Formulation Patent Landscape U.S. Patent 3,888,995 claims an anhydrous or nearly anhydrous cream vehicle based on a saturated C16-C24 fatty alcohol and a glycol solvent, principally propylene glycol. The patent does not claim a corticosteroid, a specific finished drug product, or a therapeutic method. Its protection is directed to the excipient vehicle and selected combinations of plasticizers, coupling agents, and penetration enhancers. Because the patent issued in 1975, its original 17-year patent term expired no later than 1992 under the pre-Uruguay Round term rules, absent an unusual term adjustment or extension. The claimed technology is therefore in the public domain. It has no current blocking effect on generic topical corticosteroid development, compounding, licensing, or commercial manufacture. What does U.S. Patent 3,888,995 protect?The patent protects a cream-like pharmaceutical vehicle with the following required architecture:
The central inventive concept is a high-glycol, fatty-alcohol vehicle that avoids conventional petrolatum and mineral-oil bases. The composition is intended to retain medication at the skin surface while supporting topical corticosteroid delivery. The phrase “consisting essentially of” is important. It generally permits additional ingredients that do not materially alter the basic and novel characteristics of the claimed vehicle. It is narrower than “comprising” but broader than “consisting of.” A formulation containing a preservative, antioxidant, active ingredient, fragrance, or other excipient could remain within the claim if the added material does not materially change the claimed vehicle characteristics. How should claim 1 be construed?Claim 1 is a combination claim. An accused formulation must generally satisfy every material limitation, either literally or under the doctrine of equivalents. Saturated fatty alcohol limitationThe composition must contain 20-35 parts by weight of a saturated fatty alcohol with 16-24 carbon atoms. Examples potentially within the structural definition include:
Claim 10 specifically identifies approximately 30 parts by weight of stearyl alcohol. Claim 11 also uses 30 parts by weight of stearyl alcohol. A formulation based only on cetostearyl alcohol requires analysis of the actual mixture. Cetostearyl alcohol commonly contains a mixture of cetyl and stearyl alcohols. If the product contains unsaturated components or significant alcohols outside the C16-C24 range, the literal claim analysis becomes formulation-specific. Glycol-solvent limitationThe glycol component must be selected from:
The claimed range is 55-80 parts by weight. A vehicle using glycerol, polyethylene glycol, butylene glycol, or pentylene glycol as the sole principal solvent would not literally meet this limitation, although a mixed system may require an element-by-element analysis. The claim does not require propylene glycol specifically. Claims 5-11 narrow the subject matter to propylene glycol embodiments, primarily 1,2-propylenediol. Water limitationThe vehicle must contain no more than 3 weight percent water. “Substantially anhydrous” reinforces the low-water requirement, although the claim expressly permits up to 3 weight percent water. A conventional oil-in-water emulsion would face a substantial claim-scope issue because it would normally contain a continuous aqueous phase or materially higher water content. A low-water emulsion or anhydrous semisolid could require closer analysis. Excluded ingredientsClaim 1 excludes compositions that are not substantially free from:
The exclusion of low-carbon materials is unusually broad in practical formulation terms. It may affect the use of ethanol, isopropanol, propanol, short-chain fatty acids, and short-chain fatty amides, depending on concentration and whether the composition remains “substantially free” of those materials. What do dependent claims 2 through 11 add?
Claim 11 is a four-component formulation totaling approximately 100 parts by weight. It is substantially narrower than claim 1 because it fixes the identity and approximate quantity of the fatty alcohol, plasticizer, penetrant, and glycol solvent. Which formulations are most exposed to the patent claims?The highest historical claim overlap would arise from an anhydrous cream containing approximately:
A formulation containing 30% stearyl alcohol, 5% PEG 6000, 5% hexanetriol, and 60% propylene glycol would closely track claim 11. The presence of a topical corticosteroid does not avoid the claims. The patent expressly contemplates use with topical corticosteroids, but the claims are directed to the vehicle. Adding hydrocortisone, betamethasone, clobetasol, triamcinolone, fluocinolone, or another active ingredient would not ordinarily remove an otherwise infringing vehicle from the claim. What formulations provide potential design-around paths?The patent’s expired status makes design-around analysis commercially relevant mainly for formulation selection, freedom-to-operate documentation, and historical litigation analysis. Potential design-around variables include:
A design-around that merely substitutes a chemically similar ingredient may still raise a doctrine-of-equivalents issue in a live patent. That issue is no longer commercially material for this patent because the patent term has expired. When did U.S. Patent 3,888,995 lose exclusivity?Patent-term analysisU.S. Patent 3,888,995 issued in the 1970s, when U.S. utility patents generally had a 17-year term measured from issuance. On that basis, the patent expired approximately 17 years after issuance and no later than the early 1990s. The patent therefore has:
The exact expiration date should be confirmed against the official USPTO patent record and any recorded term adjustment or terminal disclaimer. The conclusion is unchanged: the patent is long expired. (United States Patent No. 3,888,995, 1975.) Is Patent 3,888,995 listed in the FDA Orange Book?The claims do not cover a specific active pharmaceutical ingredient, dosage strength, dosage form, or approved finished drug product. They cover a general topical pharmaceutical vehicle. That subject matter is ordinarily not the basis for an Orange Book patent listing. FDA Orange Book listings generally concern patents claiming an approved drug substance, drug product, or method of using the approved drug. A general excipient vehicle patent would not normally create a listed patent barrier for an abbreviated new drug application. The practical result is that this patent would not ordinarily support a Paragraph IV certification or a 30-month stay under Hatch-Waxman. Those mechanisms apply to unexpired patents listed for an applicable reference-listed drug. (FDA, 2024; 21 U.S.C. § 355(j).) Are Paragraph IV challenges relevant?No. A Paragraph IV challenge is not the appropriate mechanism for an expired, unlisted vehicle patent. A generic applicant developing a topical corticosteroid product would instead assess:
Patent 3,888,995 does not itself create a current Paragraph IV risk. What patent landscape surrounds the claimed vehicle?The relevant landscape has several distinct layers. Active-ingredient patentsTopical corticosteroids may have had compound, salt, polymorph, synthesis, or use patents. Those rights are separate from the vehicle claims in Patent 3,888,995. Formulation patentsLater patents may claim:
A later formulation patent could remain relevant even though Patent 3,888,995 has expired. Method-of-use patentsThe patent does not claim treatment of a specific disease or a specific corticosteroid regimen. It therefore should be separated from later method-of-use claims involving psoriasis, eczema, dermatitis, lichenification, or other dermatological conditions. Manufacturing patentsThe claims do not recite a manufacturing sequence, mixing temperature, homogenization step, particle-size requirement, or filling process. Manufacturing barriers would need to arise from separate process patents or know-how. Geographic coverageThe patent’s legal effect was limited to the United States. Any corresponding foreign applications or patents would have required separate prosecution and separate expiration analysis. Expiration of the U.S. patent does not establish the status of foreign counterparts. How strong was the patent estate?The estate was narrow in product architecture but broad enough to cover a recognizable class of anhydrous glycol-fatty-alcohol vehicles. Its historical strengths included:
Its limitations included:
The patent’s present strength is zero as an exclusionary right because the patent term has expired. Its technical disclosure may still have historical value, but the claims cannot block current practice. Which companies are challenging the patent?No current challenger landscape is relevant. The patent is expired, and an expired patent does not support a current exclusionary dispute, Paragraph IV challenge, or biosimilar competition proceeding. No current licensing or settlement obligation can be inferred from the claim text. Any historical license, assignment, litigation, or settlement would require review of the USPTO assignment records and federal court docket data. Such arrangements, if they existed, would not restore patent exclusivity after expiration. What generic launch risks exist?Patent 3,888,995 creates no present generic-launch risk. A company can develop and market a topical product using the disclosed vehicle without obtaining permission under this patent. The meaningful launch risks are instead product-specific:
Key Takeaways
FAQsDoes adding a corticosteroid avoid infringement of Patent 3,888,995?No. The patent claims the vehicle. Adding a corticosteroid would not avoid the claims if the underlying vehicle satisfied all required limitations. The patent is expired, so this question has no current enforcement consequence. Does a propylene-glycol cream automatically fall within Patent 3,888,995?No. The formulation must also contain the required amount of a C16-C24 saturated fatty alcohol, fall within the quantitative ranges, satisfy the low-water limitation, and avoid the specified excluded materials. Is claim 11 a recipe for a currently protected commercial product?No. Claim 11 identifies a specific vehicle composition, but the patent protecting it has expired. The composition may be used without a license from the patent owner, subject to other applicable rights. Can a formulation with 4% water avoid claim 1?It would likely fall outside the express “0 to 3 weight percent water” limitation. The analysis would still depend on the total formulation and any doctrine-of-equivalents argument, but no such patent enforcement issue remains because the patent is expired. Does this patent protect transdermal delivery of corticosteroids?No. It claims a topical vehicle suitable for retaining and distributing medication on the skin. It does not claim a transdermal system, a specific corticosteroid, systemic delivery, or a therapeutic treatment regimen. ReferencesFood and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations. U.S. Department of Health and Human Services. United States Patent No. 3,888,995. (1975). Pharmaceutical vehicle. United States Patent and Trademark Office. 21 U.S.C. § 355. (2024). New drugs. United States Code. More… ↓ |
Drugs Protected by US Patent 3,888,995
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| >Applicant | >Tradename | >Generic Name | >Dosage | >NDA | >Approval Date | >TE | >Type | >RLD | >RS | >Patent No. | >Patent Expiration | >Product | >Substance | >Delist Req. | >Patented / Exclusive Use | >Submissiondate |
International Family Members for US Patent 3,888,995
| Country | Patent Number | Estimated Expiration | Supplementary Protection Certificate | SPC Country | SPC Expiration |
|---|---|---|---|---|---|
| Belgium | 737875 | ⤷ Start Trial | |||
| Canada | 989304 | ⤷ Start Trial | |||
| Switzerland | 516312 | ⤷ Start Trial | |||
| Germany | 1934334 | ⤷ Start Trial | |||
| Denmark | 124857 | ⤷ Start Trial | |||
| France | 2013281 | ⤷ Start Trial | |||
| >Country | >Patent Number | >Estimated Expiration | >Supplementary Protection Certificate | >SPC Country | >SPC Expiration |
