Invalidity dossier
US 4364923
Added 9/23/2026, 10:03:35 PM
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Patent summary
Title, assignee, inventors, filing/issue dates, abstract, and a plain-language overview of the claims.
Patent Overview — US 4,364,923 ("Chemical compounds")
Bibliographic data (from the supplied excerpt): Application US06/259,015; inventors Peter B. Cook and John H. Hunt; original and current assignee Allen and Hanburys Ltd; priority date 1972-04-20; filing date 1981-04-30; granted/publication date 1982-12-21; anticipated expiration 1999-12-21; status "Expired - Lifetime." Classification A61K9/008 (pressurized metered dose inhalers).
Purpose: The invention concerns antiinflammatory steroids (corticosteroids) for aerosol administration, particularly for inhalation into the bronchial system. The stated problem: when micronised beclomethasone dipropionate (2–5 microns) is filled into aerosol containers with propellants 11 and 12, crystals above 20 microns form, which are too large to pass the trachea.
Plain-language scope: The patent provides an antiinflammatory steroid as a crystalline solvate with a halogenated hydrocarbon (or such material from which part or all of the hydrocarbon has been removed), with substantially all particles small enough for inhalation (less than 20 microns, preferably 2–5 microns). "Solvate" is used generally—any crystalline material in which steroid and solvating species are associated; the ratio need not be stoichiometric. Propellant 11 (trichloromonofluoromethane) is particularly preferred; solvates with propellants 12, 113, 114, 115, chloroform, and dichloromethane are also described. The solvates resist crystal growth in propellant suspensions. Formulations generally comprise a micronised solvate suspension in propellants 11 and 12 (ratio 1:2 to 1:4, e.g. about 1:3) with a dispersing agent (oleic acid especially convenient; also sorbitan trioleate, dioctyl sodium or calcium sulphosuccinate). Preparation methods include contacting solvent-free steroid with the solvating solvent (optionally ball milling) or codistillation with a solvent such as methanol. Metered doses contain 10–1000 µg, preferably 20–250 µg; beclomethasone dipropionate suitably 30–80 µg, preferably about 50 µg. Specific infrared spectra are reported for the solvates.
What the excerpt does not establish: It is marked "[Excerpt only; consult the source for omitted text.]" Full claims, the complete list of embodiments, figures, and any prosecution history are not reproduced here. No litigation, ownership-transfer, validity, or prior-art analysis is provided.
Generated 10/1/2026, 9:33:48 PM
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Litigation summary
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Proceedings on file (0)
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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
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Obviousness
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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.