Invalidity dossier
US 6458387
Sustained release microspheres
Current assignee: Baxter Healthcare SA
Added 9/23/2026, 4:43:20 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 — US6458387B1
Title: Sustained release microspheres
Patent number: US6458387B1
Application number: US09/420,361
Inventors: Terrence L. Scott; Larry R. Brown; Frank J. Riske; Charles D. Blizzard; Julia Rashba-Step
Original assignee: Epic Therapeutics Inc.
Current assignee (as listed): Baxter Healthcare SA; Baxter International Inc.
Priority/filing date: 1999-10-18
Publication (grant) date: 2002-10-01
Legal status (as listed): Expired – Lifetime; anticipated expiration 2019-10-18
Purpose and plain-language scope. The patent is titled "Sustained release microspheres." The excerpt's prior-art keyword and classification data show the disclosed subject matter centers on microspheres, sustained-release formulations, an active agent (also called active substance, drug, or therapeutic agent), and a complexing agent, along with particles, water-soluble polymers, and methods of making and incorporating these. Recurring terms indicate optional use of polysaccharides, nucleic acids, proteins, peptides, and hormones, with leuprolide appearing frequently in the claims/description data. Process-related terms include phase separation, cross-linking reagents, incubation, centrifugation, and formation reactions. Metal ions such as calcium and magnesium and cations appear in the data.
Basis and limitations. The supplied excerpt is largely a bibliographic, classification, and keyword-frequency listing from the Google Patents page. It does not include the actual claim language, the written description, examples, or figures. No prosecution history, claim construction, or legal conclusion is provided.
What the excerpt does not establish. It does not establish the precise scope of any claim, the specific formulation components or ratios, release profiles, or the exact methods recited. It does not establish validity, enforceability, infringement, or the accuracy of the listed assignees or legal status (the source itself labels legal status and assignees as assumptions). It does not establish a complete prior-art picture. Per the operating rules, no litigation, ownership-transfer, validity, or prior-art research was performed or inferred.
Source: https://patents.google.com/patent/[US6458387](/patent/US6458387)/en
Generated 10/1/2026, 9:44:16 PM
Cases on file (0)
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Litigation summary
Past and pending lawsuits — plaintiffs, defendants, jurisdictions, outcomes, and notable rulings.
Proceedings on file (0)
All PTAB activity →AIA trial proceedings (IPR / PGR / CBM) filed at the USPTO Patent Trial and Appeal Board against this patent. Sourced from the USPTO Open Data Portal and refreshed every six hours; each proceeding number deep-links to the PTAB E2E docket.
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.