Invalidity dossier
US 4657901
Pharmaceutical composition
Current assignee: Sheiseido Co Ltd
Added 9/23/2026, 4:38:56 PM
Active provider: DeepSeek · deepseek-flash
Patent summary
Title, assignee, inventors, filing/issue dates, abstract, and a plain-language overview of the claims.
Patent Overview — US 4,657,901
Title: Pharmaceutical composition
Patent number: US4657901A
Application number: US06/648,276
Inventors: Haruhiko Ueda, Hidekazu Toyoda, Minoru Fukuda
Original assignees: Shiseido Co. Ltd. and Takeda Chemical Industries Ltd. (listed as "Sheiseido Co Ltd" in the source)
Priority dates: 1983-09-07 (JP16435683A) and 1984-07-27 (JP15700984A)
Filing date: 1984-09-07
Publication/grant date: 1987-04-14
Status shown: Expired – Fee Related; anticipated expiration 2004-09-07.
Purpose: The patent describes a topical preparation for treating acne, a "chronic inflammatory lesion occurring in the hair follicle, principally in the pilosebaceous gland system." Existing topical therapies relied on sebum-excretion depressants and antimicrobials, which the text says often failed clinically against Propionibacterium acnes.
Plain-language scope: The composition contains three elements: (1) "Compound [I]," a steroid of the given formula — including its 17-position esters and ethers — whose saturated/unsaturated 9(10) form includes oxendolone (16β-ethyl-17β-hydroxy-4-estren-3-on); (2) a keratolytic agent such as sulfur, selenium disulfide, urea, benzoyl peroxide, resorcinol, salicylic acid, or vitamin A acid (urea and resorcinol preferred); and (3) a pharmaceutically acceptable carrier. The text states the combination gives an "unexpectedly enhanced therapeutic effect." Adding a gelling agent (e.g., carboxyvinyl polymer) and alcohol (e.g., ethyl alcohol, benzyl alcohol) is said to further improve absorption. Claimed concentration ranges in the description: Compound [I] about 0.001–2 W/V%; keratolytic agent about 0.001–15 W/V%; gelling agent about 0.001–20 W/V%; alcohol about 5–70 W/V%; pH 4–8.
What the excerpt does not establish: It does not reproduce the actual claims, examples, or experimental data (the text breaks off mid-sentence in the formulation examples). It provides no litigation, validity, or ownership-transfer information beyond the recorded 1995 assignment of a 50% interest to Shiseido Company, Ltd.
Generated 10/1/2026, 9:44:20 PM
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Litigation summary
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Proceedings on file (0)
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No PTAB proceedings on file. This patent has not been challenged via IPR, PGR, or CBM. The absence is itself a signal — well-asserted patents eventually attract IPRs. The LLM analysis below may surface filings the ODP feed hasn’t indexed yet.
PTAB challenges
AIA trial proceedings at the USPTO Patent Trial and Appeal Board — IPR, PGR, and CBM. Petitioners, judge panels, claim-level invalidation outcomes from Final Written Decisions, and Federal Circuit appeals. The single most important defensive datapoint after litigation history.
Assignment history
Inventors, original assignee, and the chain of ownership recorded with the USPTO — including the correspondent attorney who recorded each assignment, since shell-LLC chains often share one repeat-player attorney even when the entity names look unrelated. Surfaces NPE / patent-troll patterns: shell-entity transfers, known asserters in the chain, repeat correspondent fingerprints, pre-litigation assignments, and bankruptcy fire-sales.
Prior art
Earlier patents, publications, and products that may anticipate or render the claims unpatentable.
Obviousness
Combinations of prior art that suggest the claimed invention would have been obvious under 35 U.S.C. § 103.
Extensions
Patent term adjustments, term extensions, continuations, divisionals, family members, and expiration dates.
Derivative works
Defensive disclosure: derivative variations of each claim designed to render future incremental improvements obvious or non-novel.