US 3916899

I'll run several targeted searches — USPTO/patent databases for the exact number, and court dockets for any 2026 activity.

Now let me check the court dockets and pull the full claim set.

Let me pull the complete claim set and check for any recent (2026) docket activity.

US Patent 3,916,899 — Summary and Analysis

Note on the identifier: I read the number literally as 3,916,899 (Google Patents publication form: US3916899A). All results below refer only to that patent; I did not substitute similar numbers. One caution: the string "the '895 patent" appears in unrelated Alza/Concerta (OROS) litigation (e.g., Alza v. Andrx, Alza v. Amneal, D. Del. No. 16-cv-914). Those opinions concern later, different Alza patents (e.g., the '798, '549, '855, '355 and '895 patents of the Concerta family), not 3,916,899. Do not conflate them.

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1. Bibliographic data (from the patent record)

Uncertainty flagged: the record shows a filing date of 1974‑02‑07 but a priority date of 1973‑04‑25 (roughly 9½ months earlier). This pattern is consistent with a continuation‑in‑part or an earlier‑application priority claim, but I could not authoritatively confirm the parent application from the sources retrieved, so treat the 1973 date as provisional (Google Patents itself labels it an assumption).

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2. Abstract (verbatim)

"A device is disclosed comprised of a wall surrounding and forming a compartment for containing a useful composition of matter and having a passageway for dispensing the composition. The wall is comprised in at least a part of a material permeable to an external fluid. The composition is soluble in the fluid and exhibits an osmotic pressure gradient against the fluid or the composition has limited solubility and is admixed with an osmotically effective compound soluble in the fluid that exhibits an osmotic pressure gradient against the fluid. [The] composition is dispensed from the device by fluid permeating into the compartment producing a solution of the soluble composition or a solution of the osmotically effective compound containing the composition, which solution in either operation is released through the passageway to the exterior of the device at a rate controlled by the permeability of the wall and the osmotic pressure gradient across the wall of the device."

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3. Plain-language overview

This is a foundational Alza "elementary osmotic pump" patent (a companion to Theeuwes & Higuchi's US 3,845,770). The invention: a pill/implant/insert with a semipermeable wall enclosing a compartment of drug (or drug + osmotic salt). Water from the environment is imbibed osmotically through the wall; the resulting solution is pushed out through a single small hole (passageway). Because the water influx is governed by the wall's permeability and the osmotic pressure differential — not by pH, stirring, or the environment — release is zero‑order (constant) and pH‑independent for a prolonged period.

The novelty claimed in this particular patent is the sizing of the passageway, from which the title derives:

• A maximum cross‑sectional area (formulated in terms of passageway length, agent release rate, diffusion coefficient D, and solubility S, with a factor F of about 2 to 1000) — chosen so that simple diffusion of agent out of the hole does not meaningfully contribute to release, i.e., the device truly operates as an osmotic pump rather than a diffusion device.
• A minimum cross‑sectional area (formulated in terms of passageway length, release rate, solution viscosity η, and the hydrostatic pressure difference ΔP, up to about 20 atm) — chosen so the hole is large enough not to throttle or structurally fail under the osmotically generated hydrostatic pressure.

Stated benefit in the specification: release "essentially free from environmental influence," independent of pH and stirring rate, with high agent loading and shelf stability.

Uncertainty flagged: the exact algebraic form of the two area equations is not fully legible in the authoritative text supplied to me, and the secondary sources I retrieved that paraphrase them (e.g., the Japanese family members JPS61103821A and JP2773857B2) are machine-translated and OCR‑garbled. The variables above are reliable; the precise equation arrangement should be verified against the printed claim text / PDF.

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4. Independent claims (plain language)

Claim 1 — The base osmotic device. An osmotic device for continuous dispensing of an active agent comprising:

• (a) a shaped wall of semipermeable material that maintains its integrity during dispensing, permeable to external environmental fluid and substantially impermeable to the active agent, the wall surrounding and forming;
• (b) a compartment containing the active agent, which is either soluble in the fluid that enters and exhibits an osmotic pressure gradient across the wall (or is admixed with an osmotically effective organic/inorganic solute); and
• (c) a passageway in the wall for dispensing agent, the passageway having a maximum cross‑sectional area (and, per the title and specification, a minimum cross‑sectional area) within the recited bounds.

In short: a semipermeable-walled reservoir with a hole drilled to a size window that guarantees osmotic (not diffusional) pumping.

Claim 12 — The composite/partial-wall device. Same functional result, but the wall is formed only in part of a semipermeable material (permeable to environmental fluid, impermeable to agent) and in the remaining part of a material impermeable to both fluid and agent; compartment containing the agent; passageway with the recited maximum cross‑sectional area. In short: the same sized-orifice osmotic pump, but with a "window" wall rather than an all-semipermeable wall.

Claim 20 — The ocular device. An ocular device for continuous, prolonged administration of an ophthalmic drug, comprising: (a) an ophthalmic drug exhibiting an osmotic pressure gradient against eye fluid; (b) a wall of semipermeable material insoluble in eye fluid, permeable to eye fluid and essentially impermeable to drug, forming a compartment containing the drug; and (c) a passageway through the wall with the recited cross‑sectional area limitation. In short: the claim-1 concept adapted as an eye insert (consistent with the bean-shaped ocular embodiment of FIGS. 2–6 and the A61F9/0017 classification).

Dependent-claim coverage (as retrieved): claims 2–11 depend from claim 1 (e.g., osmotically effective solute; vaginal, subcutaneous‑implant and intrauterine adaptations; wall materials cellulose acetate, methyl cellulose, polyvinyl alcohol, polyurethane; single passageway; dispersant; gelling agent; binder). Claims 13–19 depend from claim 12 (solute addition; bioerodible wall, including polyglycolic/polylactic acid; water-insoluble material; mouth/oral use; pesticides, insecticides, germicides, fungicides, algicides; plant nutrients). Claims 21+ depend from the ocular claim 20.

Two caveats on claim numbering: (i) I could only retrieve the claim set up to about claim 20 from third‑party renderings; I cannot authoritatively confirm whether any further independent claims exist among claims 21–36 (the specification does describe a method of dispensing and "method" terminology appears, so a method claim is plausible, but I have not verified it). (ii) In the third-party rendering retrieved, claim 1's element "b" appears mislabeled as claim "2," making the dependent-claim numbering appear off by one — the substance of claims 1, 12 and 20 above is reliable, but precise numbering of the short dependent claims should be checked against the printed patent.

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5. USPTO and court-docket findings (as requested)

USPTO / patent databases: The record is confirmed at uspto.report/patent/grant/3916899 and Google Patents US3916899A — title, abstract, assignee (Alza), claim count (36) and legal status (Expired – Lifetime, anticipated expiration 1992‑11‑04) all match.

Court dockets — no 2026 activity found for this patent number. The only litigation entries surfaced for 3,916,899 are the historical ones listed on Google Patents under "Unified Patents Litigation Data":

• CAFC (Court of Appeals for the Federal Circuit), case 21-2335 (a 2021 appeal, not 2026);
• D.N.J. 2:19-cv-15343 and D.N.J. 3:18-cv-11213.

Important interpretation caveat: because 3,916,899 reached its anticipated expiration on 1992‑11‑04, it could not have been asserted in 2018/2019/2021 infringement actions. Those docket entries most plausibly reflect cases in which the patent was cited or referenced (e.g., as prior art or background), not asserted. I could not retrieve the docket contents to confirm this, and my final docket query hit a search-step limit — so my "no 2026 docket activity" conclusion is not exhaustive. If a definitive 2026 CAFC/D.N.J. sweep is needed, that should be re-run against PACER/Unified Patents directly.

No 2026 date conflict to report, other than that no live 2026 matter tied to this number appeared.

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6. Independent corroboration of significance

• Later Alza patent US 4,016,880 (Theeuwes) states on its face that it is "a unique modification of the dispenser of U.S. Pat. No. 3,916,899," and incorporates that patent's disclosure by reference — direct evidence of this patent's foundational role.
• Dozens of later osmotic-dosage-form patents (e.g., US 4,088,864; US 4,285,987; US 5,614,578; EP 0 254 394; EP 2 426 132; EP 2 298 748) cite US 3,916,899 as the authority on osmotic passageway sizing and formation.
• The peer-reviewed literature (e.g., Theeuwes & Higuchi, US Patent 3916899, 1975; Santus & Baker, J. Control. Release 35:1–21 (1995)) treats it as a landmark osmotic-delivery reference.

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Bottom line: US 3,916,899 is Alza's Theeuwes/Higuchi patent on passageway dimensioning in an osmotic dispenser — filed 1974‑02‑07, issued 1975‑11‑04, now long expired (1992). Its three substantive independent claims cover (1) the sized-orifice osmotic device, (2) the same device with a partly-impermeable "window" wall, and (3) an ocular adaptation. No 2026 USPTO or CAFC activity specific to this number was found, and the historical docket hits almost certainly reflect citation rather than assertion given the 1992 expiration — but that last point is inference, not verified docket content.

I'll run targeted searches against litigation-database sources for this exact patent number.

Initial searches were noisy. Let me query the litigation databases directly and the specific docket numbers.

Let me query the specific docket identifiers and court-docket repositories.

I completed the searches but hit the tool-step limit before I could verify every docket. Here is what I can state with confidence, and where I cannot.

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Litigation involving U.S. Patent 3,916,899

Bottom line

I found no case in which U.S. Patent 3,916,899 was asserted as a patent-in-suit. Every docket linkage I could retrieve for this exact number resolves to either (a) a case concerning entirely different, much later patents, or (b) a record I could not open. The patent issued 1975‑11‑04 and, as 17‑year‑from‑issue term, expired 1992‑11‑04 — nine months before the earliest of the docket entries below. That timing is itself the strongest evidence that these are citation matches, not assertion matches.

I did not auto-correct the number. All results below are keyed to 3,916,899 only.

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1. Docket entries surfaced for this patent number

The only linkage data is the "Unified Patents Litigation Data" block displayed on the Google Patents record for US3916899A. There are three entries:

Two notes on this block:

• The word "Critical" appearing next to each entry in the Google Patents HTML is a UI timeline marker, not an indicator of legal significance or of the patent's role in the case. It should not be read as describing the litigation.
• The Unified Patents dataset is a heuristic number-to-docket mapping (CC-BY 4.0). It is well known to produce false positives for old patents whose numbers appear in case documents, IDS submissions, expert reports, or the specifications of the patents actually in suit. For a patent that expired in 1992, any post-1992 docket match is presumptively a citation match.

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2. What D.N.J. 2:19‑cv‑15343 actually is

I verified this docket. It has nothing to do with 3,916,899:

Outcome on the merits (Dkt. 145, final judgment entered 2022‑02‑23): the '262 patent was held valid, enforceable and infringed (with injunction against DRL); the '427 patent was held valid, enforceable and not infringed, with all claims and counterclaims as to '427 dismissed with prejudice.

Sources: CourtListener docket 15918136 (Dkt. 145, the stipulated final judgment, and the Feb. 23, 2022 judgment entry); docket summary at the CourtListener-derived case index.

Conclusion: 3,916,899 is not a patent-in-suit in 2:19‑cv‑15343. Its appearance is a dataset false positive.

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3. Entries I could not verify

• CAFC 21‑2335. I could not retrieve the docket contents. All I can say is that this is a 2021 Federal Circuit appeal, thirteen years after 3,916,899 expired. On that basis alone it cannot be an appeal of an infringement judgment on this patent. I decline to speculate about the subject matter.
• D.N.J. 3:18‑cv‑11213. My targeted search for this case number returned zero results. It is also a 2018 filing — 26 years after expiration. Unverified.

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4. Why no infringement suit on 3,916,899 could have survived after 1992

As a matter of law, this is dispositive for the modern docket hits:

1. Expiration. Issued 1975‑11‑04; 17‑year term (pre‑URAA, since the application was filed 1974‑02‑07) → expired 1992‑11‑04. Google Patents records "Anticipated expiration 1992‑11‑04" and legal status "Expired – Lifetime." An expired patent cannot be infringed (35 U.S.C. § 271; a necessary element — an unexpired claim — is absent).
2. Damages window. Even had it been asserted, 35 U.S.C. § 286 bars recovery for infringement more than six years before suit. Any 2018/2019/2021 suit could reach back only to 2012–2015 — two decades post-expiration.
3. Therefore, the 2018/2019/2021 docket entries are consistent only with citation, e.g. as prior art or background in an IDS or specification. That is inference from the expiration date; I could not read the underlying dockets.

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5. What I could not rule out

I cannot exclude infringement litigation filed during the enforceable window (1975‑1992). Pre‑PACER records are incompletely digitized, and Alza was a famously litigious patentee in that era. I found no such case, but absence of evidence here is not evidence of absence. If a definitive answer is required, the right searches are:

• Westlaw KeyCite / Lexis CourtLink on 3,916,899 (the classic litigation-history method used for old patents);
• The USPTO's own litigation-search methodology (Litigation Search Report), which is exactly how old-patent history is normally reconstructed;
• Manual review of the CCH/Food Drug Cosmetic Law Reports for 1975–1992 pharmaceutical patent suits involving Alza.

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6. Number-confusion warning (repeating and sharpening the prior section's flag)

A distinct risk in this family is conflation with the Alza "OROS/Concerta" patents litigated in Alza v. Andrx, Alza v. Amneal (D. Del. No. 16‑cv‑914) and related cases. Those involve much later Alza patents and are not 3,916,899. I did not have sufficient verification to pin the exact registration numbers in that family during this session, so I will not state them; treat any "'895 patent" reference in post‑2000 Alza/ADHD‑drug litigation as presumptively a different patent unless the full 7‑digit number is confirmed.

Also not to be confused: DE 3916899 A1 (Robert Bosch GmbH, published 1990‑11‑29) — a German patent document with a coincidentally similar string, which appears in search results alongside the US number.

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7. Contradictions with the previously generated section

• No contradiction found. The prior section's conclusion — that the CAFC 21‑2335 / D.N.J. 2:19‑cv‑15343 / 3:18‑cv‑11213 hits most plausibly reflect citation rather than assertion — is confirmed and strengthened for 2:19‑cv‑15343, which I positively identified as a Celgene v. Dr. Reddy's pomalidomide ANDA case.
• One correction to scope: the prior section described its "no 2026 docket activity" finding as possibly non‑exhaustive due to a search‑step limit. I hit the same limit again. The 2026 sweep remains uncompleted. Given the 1992 expiration, however, a 2026 assertion is legally impossible, so the practical risk of the gap is negligible.
• Minor dating discrepancy to flag, not resolve: the prior section gives "Current Date: April 26, 2026" in the response header while the system date in my task is 2026‑10‑01. I've used the patent records' own dates for all substantive findings; the discrepancy does not affect them.

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8. Where to verify independently

• Google Patents US3916899A — source of the three litigation entries
• Unified Patents litigation portal — the underlying dataset; search by patent number 3916899, then open each linked case to confirm the patents actually asserted
• CourtListener docket 15918136 — verified record for D.N.J. 2:19‑cv‑15343
• PACER / CAFC docket for 21‑2335 and D.N.J. 3:18‑cv‑11213 — both still open items

Caveat on this response: entries 1 and 3 remain unverified, and the 1975–1992 window is unswept. I have said so explicitly rather than filling the gap by inference.

I'll verify the "no PTAB activity" baseline with targeted searches before writing.

PTAB proceedings on US 3,916,899 — no AIA trials on file

Bottom line up front: there are zero AIA trial proceedings on US 3,916,899. The structured "PTAB proceedings on file" block (USPTO Open Data Portal, canonical source) returned no AIA trial proceedings, and my independent web searches found no IPR, PGR, or CBM petition, institution decision, final written decision, or appeal naming this patent. There is no proceeding number to report, no panel to name, and no claim-level disposition to quote — and I will not manufacture one.

What follows therefore treats the absence as the substantive finding, explains why it is structural rather than a data gap, and flags the nomenclature hazards that could make a defendant think this patent has PTAB history when it does not.

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Proceedings overview

Total AIA trial proceedings on US 3,916,899: 0 — 0 active, 0 with claims invalidated, 0 with claims sustained, 0 settled, 0 with institution denied. The defensive posture this gives a defendant is not "hardened patent" and not "claims are dead" — it is "there is nothing here to fight, because the patent expired on 1992-11-04." A defendant does not need an IPR-based defense; it needs a calendar.

The absence is expected, and I'd flag it as diagnostic, not merely informational. Three structural bars explain it:

The patent's term ran the pre-URAA 17-years-from-issue rule: issued 1975-11-04, anticipated expiration 1992-11-04 (as recorded in the Google Patents legal-status field and confirmed at uspto.report/patent/grant/3916899). Practically every demand letter citing this number would be time-barred under 35 U.S.C. § 286 (six-year damages lookback) as well.

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Per-proceeding detail

None to give. For completeness and auditability, here is what I checked and what I found:

Nomenclature hazards — do not mistake these for PTAB history on 3,916,899

This is where a defendant could go wrong, and it is worth stating precisely:

1. Trailing-digit collision ("the '899 patent"). Searches for "'899 patent" + IPR readily surface IPRs on entirely different patents — e.g., the "’899 patent" discussed in Realtime Data, LLC v. Iancu, 912 F.3d 1368 (Fed. Cir. 2019) is a USB-hub patent, not an Alza osmotic patent. A party searching by shorthand rather than by full number will get false positives.
2. "Alza's '895 patent" in the Concerta/OROS litigation. The prior-analysis section flagged this, and my searches reconfirm it: opinions in the Alza/Mylan and Alza/Andrx/Amneal Concerta line (e.g., Alza Corp. v. Mylan Labs., 388 F. Supp. 2d 710 (D. Del. 2005); D. Del. No. 16-cv-914) refer to an "Alza '895 patent" that is a later, different patent in the OROS/Concerta family. It is not 3,916,899. I did not independently verify which patent number that shorthand maps to, so I will not assert one — only that it is not this patent, because a patent expiring in 1992 cannot be the basis of post-2000 infringement claims.
3. Historical docket entries on this number are citations, not assertions. Google Patents lists D.N.J. 2:19-cv-15343, D.N.J. 3:18-cv-11213, and CAFC 21-2335 under this patent's "Unified Patents Litigation Data." Given the 1992-11-04 expiration, these almost certainly reflect the patent being cited or referenced rather than asserted. I could not retrieve the docket contents to confirm that, and no corresponding PTAB petition accompanies any of them — so even if a 2018/2019/2021 case mentioned this number, no AIA trial flowed from it. (This matches the caveat already recorded in the prior analysis; there is no contradiction to flag, only the same open question.)
4. Reexamination is a different dataset. Ex parte or inter partes reexamination (pre-AIA) would not appear in an AIA-trial inventory at all. I did not find evidence of any such proceeding on 3,916,899, but I also did not run a dedicated reexamination-history check — treat that as unverified rather than negative.

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Strategic summary

Claim status. All 36 claims are UNTESTED in any AIA forum — none canceled, none sustained, none narrowed. That is not because the claims are strong; it is because they expired on 1992-11-04 and no petitioner ever had a reason to spend money on them. Any statement that "claims 1–5 were canceled" or "the patent survived two IPRs" would be false as to this number.

Estoppel landscape. No § 315(e)(2) estoppel exists and none can arise. Estoppel attaches only to a petitioner that obtained a final written decision; there is no petitioner, no FWD, and therefore no ground that a prior challenger "raised or reasonably could have raised." A defendant today faces zero PTAB-derived estoppel constraints. Its § 282 invalidity defenses are wholly unencumbered — though, as a practical matter, invalidity need not be reached at all.

Pattern signals. No recurring petitioner; no serial IPR campaign; no patent-owner appeal practice (there is no FWD to appeal, and the recorded CAFC case 21-2335 predates nothing relevant — it is a 2021 entry, and the patent's own term ended in 1992). No defensive aggregator (Unified Patents or similar) has ever touched this patent. The patent's modern relevance is purely as prior art and as doctrinal bedrock: US 4,016,880 (Theeuwes/Damani) states on its face that it is "a unique modification of the dispenser of U.S. Pat. No. 3,916,899" and incorporates that disclosure by reference; US 4,610,686 (Alza) states that "[a] detailed description of osmotic passageways, and the maximum and minimum dimensions for osmotic passageways are disclosed in U.S. Pat. Nos. 3,845,770 and 3,916,899"; and the Santus & Baker survey of the osmotic-delivery patent literature (J. Control. Release 35:1–21 (1995)) identifies 3,916,899 as the reference giving "a formula from which the optimum size of the laser-drilled hole in the device can be obtained." That is the patent's real function in 2026 — a citation, not a cause of action.

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Recommended next steps

1. If a demand letter cites US 3,916,899, the answer is a date, not an IPR. The term expired 1992-11-04 (17 years from the 1975-11-04 issue date; pre-URAA term). Conduct after that date cannot infringe, and any suit would also confront the six-year damages bar of 35 U.S.C. § 286. Because there is no FWD to quote, there is no claim-level disposition to link — the correct cite is the patent's own legal-status record, e.g., Google Patents US3916899A ("Expired – Lifetime," anticipated expiration 1992-11-04) and uspto.report/patent/grant/3916899.
2. Verify the number before responding. Confirm the letter actually identifies 3,916,899 and not a Concerta-era OROS patent whose shorthand ends in "895" (or an unrelated "'899" patent). A mismatch here is the single most likely explanation for a demand premised on a 50-year-old expired patent, and it changes the response entirely.
3. No PTAB docket to monitor. There are no pending proceedings, no institution deadlines, no oral hearing dates, and no statutory one-year FWD deadline to track. If you want a belt-and-suspenders confirmation, query PTAB E2E (https://ptacts.uspto.gov/ptabweb/) by patent number — but expect a null result, consistent with the ODP block in this prompt.
4. Re-run the docket check if litigation posture matters. My earlier docket sweep (per the prior analysis) was not exhaustive, and I could not retrieve docket contents for D.N.J. 2:19-cv-15343, D.N.J. 3:18-cv-11213, or CAFC 21-2335. If you need to know why a 1992-expired patent appears in 2018–2021 dockets, pull those dockets directly from PACER/CourtListener — but note that whatever the answer, it produced no AIA trial.
5. If you need a reexamination check, run it separately. AIA-trial inventories (and this analysis) will not surface pre-AIA ex parte/inter partes reexamination. I found no evidence of one, but that is unverified, not confirmed-absent.

Confidence note. I am highly confident in the "zero AIA trial proceedings" conclusion: the canonical ODP block is silent, and four independent searches produced no petition, decision, or appeal. I am not asserting anything about the contents of the three historical docket entries — only that no PTAB proceeding traces to them.

I'll research the assignment record for US 3,916,899 across the USPTO Assignment Center and corroborating sources.

Let me try to locate the actual USPTO assignment records and the Alza corporate chain.

Assignment-record caveat (read first)

I did not retrieve the USPTO Assignment Center records for US 3,916,899. My queries against the Assignment Center / assignment.uspto.gov index did not surface any recorded reel/frame entries for this patent number, and I exhausted my search budget before I could query the Assignment Center search endpoint directly (the assignment-api.uspto.gov lookup attempt returned a step-limit cutoff, not a result).

Consequently:

• I am not reporting any reel/frame numbers, execution dates, recording dates, or correspondents of record for this patent. I will not infer or reconstruct them.
• Everything below that is not a reel/frame citation comes from the corporate/legal record (Google Patents legal events, the Belgian Competition Authority merger decision, J&J SEC filings, Wikipedia/encyclopedia summaries of Alza). Treat the ownership chain as a corporate-history chain, not a verified assignment chain.
• Per your instruction, the honest statement is: I cannot confirm whether the Assignment Center has records for this patent. The correct posture is "INS records not retrieved — re-query required," not "no records exist."

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Inventors

Unusual-pattern check — no "inventor flight" signal. There is no evidence that either inventor departed Alza within 12 months of the 1974‑02‑07 filing. Theeuwes remained an Alza R&D leader essentially until the J&J acquisition; Higuchi (d. 1987) remained an Alza co-founder/consultant. Both were Alza-aligned from the outset, which is consistent with the patent issuing directly to Alza Corp with no intervening inventor→third-party assignment.

(Caveat: the inventors' employment at filing is reconstructed from biography/corporate history, not from a verified "Assignment of Invention" record.)

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Original assignee

Alza Corporation — named original assignee on the face of the patent (Google Patents "Original Assignee: Alza Corp"; "Current Assignee: Alza Corp").

• Primary line of business: drug-delivery R&D and products — the OROS® (Osmotic Release Oral System) elementary osmotic pump is Alza's signature platform, and US 3,916,899 is the passageway-dimensioning member of the Alza osmotic-pump family (companion to US 3,845,770).
• Did they ship a product embodying the claims? Yes. The claimed "wall + sized passageway" architecture is the OROS platform commercialized in oral osmotic products (e.g., the nifedipine GITS / Procardia XL generation, Ditropan XL, Concerta, Glucotrol XL). The successoral patents in the chain expressly incorporate US 3,916,899's passageway teachings.
• Current status: Alza was a publicly listed company until acquired by Johnson & Johnson in a stock-for-stock merger announced 2001‑03‑27, valued at ~US$10.5 billion (Express Merger Sub Inc. merged into Alza; Alza survived as a wholly-owned J&J subsidiary and retained the "Alza" name — per Belgian Competition Authority Decision No. 2001‑C/C‑39). J&J subsequently wound down the standalone Alza operation (Mountain View site closed around 2011–2012). I flag mild uncertainty on the precise current legal status of the "Alza Corporation" entity today — it is described as a J&J subsidiary rather than dissolved, but I did not verify its 2026 corporate status.

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Assignment timeline

USPTO Assignment Center records for US 3,916,899 were not retrieved. I am therefore providing the verifiable corporate-transaction record below and explicitly marking it as not a substitute for reel/frame data. No reel/frame numbers are asserted.

• 1974‑02‑07 — application filed by Alza Corp (application 05/440,281). Whether an inventor→Alza assignment was separately recorded with the USPTO — and under which reel/frame — is unverified.
  • Conveyance: (unverified; typically "Assignment" for this vintage)
  • Assignor: (unverified)
  • Assignee: Alza Corporation (as reflected on the printed patent)
  • Correspondent: (unverified — not retrieved)
  • Context: original corporate ownership by the filing entity.
• 1975‑11‑04 — patent issued to Alza Corp. No change of owner reflected.
  • Note: 1975-era patents issued to their corporate assignee; a pre-issuance assignment to Alza would be the expected first link, but I could not confirm it.
• 2001 (merger agreement 2001‑03‑26; announced 2001‑03‑27; cleared/closed 2001) — Alza acquired by Johnson & Johnson via stock-for-stock merger. Because Alza survived as the acquiring group's subsidiary, this is a corporate merger, not necessarily a separately recorded patent assignment. Source: Belgian Competition Authority Decision No. 2001‑C/C‑39; J&J Form 425/S‑4 filings (2001).
  • Conveyance: Merger (corporate; INS recording status unverified)
  • Assignor: Alza Corporation shareholders / Express Merger Sub Inc. structure
  • Assignee: Johnson & Johnson (parent); Alza Corporation remains the record-owning subsidiary
  • Correspondent: (unverified — not retrieved)
  • Context: internal consolidation into a public operating parent — not a fire-sale and not a transfer to an NPE.
• 1992‑11‑04 — anticipated expiration (per Google Patents legal status). The patent was already ~9 years expired before the J&J merger, so any post-1992 transfer could not have been for assertion purposes.
• 2018/2019/2021 litigation entries (D.N.J. 2:19‑cv‑15343; D.N.J. 3:18‑cv‑11213; CAFC 21‑2335) appear in the Google Patents "Unified Patents Litigation Data" block. These cannot be assertions of US 3,916,899, which expired in 1992; they are most plausibly citation/reference hits or family-mate litigation. (This flags the same caution raised in the earlier section about Confusion with the Concerta-family "'895 patent" — unrelated.)

If, after you re-run the Assignment Center query, the only record is the original inventor→Alza assignment, that is itself the finding: the patent never left the original operating-company assignee.

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Timeline diagram

timeline
    title Ownership history of US 3916899
    1968 : Alza Corporation founded
    1973 : Earliest priority date claimed
    1974 : Application filed by Alza inventors
    1975 : Patent issued to Alza Corp
    1992 : Patent expires
    2001 : Alza acquired by Johnson and Johnson

(This is a corporate-event timeline. It is not a rendering of verified USPTO assignment records, because none were retrieved.)

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NPE / troll-pattern signals

Governing limitation: every "not present" below is based on the corporate history, not on an examination of reel/frame entries, because no assignment records were retrieved. Signals requiring correspondent or reel/frame data are marked unclear, not "not present."

1. Shell-entity transfer — Not present (on available evidence). The only ownership change in the record is Alza→Johnson & Johnson (2001 corporate merger), i.e., operating company → operating company. No LLC with an "IP/Patents/Holdings" suffix appears anywhere in the retrievable record.
2. Known asserter in the chain — Not present. Neither Alza Corporation nor Johnson & Johnson appears on the Acacia / Marathon / IV / Wi‑LAN‑Conversant / Vringo / Pendrell / Round Rock / Spangenberg-type NPE lists. Both are/have been operating pharmaceutical companies.
3. Repeat correspondent across the chain — Unclear / no data. I did not retrieve a single correspondent of record for this patent, so recurrence cannot be assessed. This is the signal most likely to change the verdict and should be the first thing re-checked in the Assignment Center (look for the correspondent on the original 1974/1975 assignment — for Alza-family patents this is typically Alza in-house counsel or the prosecuting firm, but I have not verified it and will not name a firm).
4. Cascading transfers — Not present. No chain of successive LLC-to-LLC assignments in the retrievable record.
5. Pre-litigation transfer — Not present. The patent's useful life ended in 1992; the 2018–2021 docket entries post-date expiration by 26–29 years and cannot be asserters of this patent.
6. Bankruptcy fire-sale — Not present. Alza was acquired in a $10.5B stock transaction; there is no Chapter 7/11 sale of Alza assets in the record.
7. Privateering — Not present. No operating-company→NPE transfer exists in the record for this patent; J&J is not asserting it against competitors.
8. Defensive aggregator (anti-NPE) — Not present. The chain does not terminate at RPX, AST, LOT, Unified Patents, or OIN. It terminates (on available evidence) at Johnson & Johnson via Alza, and then at patent expiration.

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Verdict

Insufficient data — with the strong caveat that nothing in the retrievable record points toward NPE involvement.

The verdict is driven by the absence of verified assignment records, not by evidence of NPE activity: I retrieved no reel/frame entries, no assignor/assignee recordings, and no correspondent of record for US 3,916,899. The only ownership events I can substantiate are (i) issuance to the original operating-company assignee Alza Corporation (Google Patents: Original/Current Assignee "Alza Corp") and (ii) the 2001 Alza→Johnson & Johnson stock-for-stock merger (Belgian Competition Authority Decision No. 2001‑C/C‑39; J&J 2001 Form 425/S‑4 filings) — operating company to operating company, with the patent already expired 1992‑11‑04. On those facts, signals 1, 2, 4, 5, 6, 7 and 8 are negative; signals 3 (repeat correspondent) and the existence/absence of any post-issue assignment are unclear because no INS records were obtained.

Re-query required for a definitive call:

• USPTO Assignment Center (same underlying records as the legacy index): https://assignmentcenter.uspto.gov/ — search by patent number 3916899.
• Legacy landing page: https://assignment.uspto.gov/patent/index.html
• Cross-check: https://patents.google.com/patent/US3916899/en (Legal Events / "Also published as" and the Unified Patents litigation block).

If the Assignment Center returns only the original inventor→Alza recording, the correct final verdict would be Operating-company / non-asserting chain terminating in the original assignee, not NPE.

I'll search for the patent's front-page references and citation record.

Prior-Art Analysis for US 3,916,899

Search status / honesty flag first: My USPTO/PACER web searches for this number hit the tool's step limit partway through the prior-art retrieval. I therefore could not fetch the printed front-page "References Cited" table (the examiner/applicant citation list) for 3,916,899 inside this session. Everything below is built from (a) the authoritative full text of the patent supplied to me, whose specification itself names and characterizes the prior art, and (b) corroborating records retrieved. Where I am supplying a citation from general knowledge rather than a retrieved record, I mark it [UNVERIFIED] and say so. I am not going to invent a tidy ten-item citation list to fill the gap.

Also flagging a date contradiction as instructed: the system header gives today as 2026-10-01, while this task states April 26, 2026. Neither date changes the analysis (the patent expired in 1992), but the inconsistency is noted rather than silently harmonized.

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1. USPTO record for 3916899 (literal reading)

Confirmed record — no similar numbers substituted:

Record corroborated at Google Patents US3916899A and uspto.report/patent/grant/3916899.

Critical framing point for a § 102 exercise: this patent expired 1992-11-04. Any anticipation analysis is therefore historical/validity-reconstruction, not a live invalidity position. More importantly, because the patent issued with all 36 claims intact, the references cited on its face were, by definition, not applied as anticipatory — they were distinguished before allowance. The analytically honest output is therefore: which claims each reference would have been asserted against, and the specific claim element that defeats the § 102 mapping. I give both.

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2. Prior art identified in the patent's own specification (authoritative)

These are the references the patent text expressly characterizes — the highest-confidence prior art for this analysis.

(a) US 3,279,996 [number confirmed in the spec text; bibliographic detail UNVERIFIED]

"Prior art diffusion systems encompassed within the above discussion are typically represented by U.S. Pat. No. 3,279,996, and the like."

• Full citation: US 3,279,996. Inventor/title/date not verifiable from the retrieved record. [UNVERIFIED — grant date ~1966, verify against USPTO before relying on it.]
• Brief description (per the '899 specification): a diffusion-controlled medicament delivery device — an enclosed capsule or multi-structured device with a wall of polymer permeable to the composition itself. The spec's stated defect: for many actives the permeation rate through the rate-controlling material "is too small to produce a useful effect," or the molecules are too large to diffuse at all; salts with ionic character "will not diffuse through most polymers."
• § 102 mapping:
  • Potentially asserted against: claims 1, 12, 20 — as the generic genus of "device comprising a wall surrounding a compartment containing a beneficial agent."
  • Why it fails / distinguishing element: no passageway; no semipermeable wall that is impermeable to the agent; release is by diffusion of the agent through the wall, not by osmotically generated fluid influx with agent exiting through a discrete orifice. Claim 1's "passageway … having a maximum cross-sectional area" is wholly absent, and element (a)'s "semipermeable … substantially impermeable to the active agent" is affirmatively contradicted (the '996 wall must be agent-permeable to work).
  • Best use: § 103 background art only.

(b) US 3,146,169 — the "sealed tablet with a hole" reference [number appears in spec as OCR "U.S. Pat. No. 3,l46,l69"; inventor/date UNVERIFIED]

"…a pharmaceutical tablet formulation comprised of a layer impermeable to both water and medication which surrounds the medication except for a hole … medication is released by uncontrolled dissolution predicated upon many variables."

• Full citation: US 3,146,169. [UNVERIFIED — I recall a ~1964 grant; verify.]
• Brief description: a tablet carrying a coating impermeable to both water and drug, breached by a single hole. Release is governed by dissolution kinetics of the drug in the hole.
• § 102 mapping — this is the most dangerous-looking reference, and the most instructive:
  • Potentially asserted against: claims 1 and 12 (a wall + a compartment + a hole).
  • Why it fails: the wall is impermeable to water, so there is no fluid-imbibition pathway and no osmotic pressure gradient across the wall — the very mechanism claim 1 recites ("permeable to an external fluid … exhibits an osmotic pressure gradient across said wall"). The spec expressly attacks this reference on three grounds: (i) dissolution-rate (not osmotic) control, (ii) pH dependence of release, and (iii) stirring-rate dependence of release. That is the § 102/§ 103 rebuttal in the applicant's own words.
  • Best use: the primary reference an examiner would combine for a § 103 obviousness attack on the concept of a single-orifice device — and the reference the "maximum/minimum passageway size" limitations exist to distinguish.

(c) US 3,538,214 — the microporous-film tablet [number confirmed in spec text; inventor/date UNVERIFIED]

"…a tablet comprised of a drug matrix coated with a microporous film permeable to fluid and drug as another prior art means for the controlled release of drug."

• Full citation: US 3,538,214. [UNVERIFIED — verify grant date.]
• Brief description: a drug-matrix tablet coated with a microporous membrane; water passes through the pores, dissolves drug, and drug exits through the pores.
• § 102 mapping:
  • Potentially asserted against: claims 1, 12 — it has a "wall" and a "passageway" (the pores).
  • Why it fails: (i) the membrane is permeable to the drug, whereas claims 1/12/20 require a wall "substantially impermeable to the active agent"; (ii) the pores are an "unspecified number of pores of variable sizes arising through manufacture" — i.e., it cannot meet the recited numerical size window of the passageway; (iii) it is pH-dependent and thus environmentally influenced, whereas each independent claim's operative premise is a pH-independent osmotic rate. This is the single most useful reference for showing why the passageway-sizing claim language is the patentable core.

(d) The bag-in-ampoule osmotic pump (Rose–Nelson type) [patent number illegible in the supplied text — do not guess it]

The specification describes, in detail, a device in which "the partially collapsed bag is housed in a glass ampoule," with a product compartment, a water compartment at the distant end, a semi-permeable membrane, and a drug release nipple; water moves through the semi-permeable membrane, swells the compartment, and the expanding rubber provides "the mechanical force necessary to eject the product solution through the nipple."

• Full citation: patent number not recoverable from the authoritative text supplied (the passage is OCR-damaged and the numerals are not present in the fetched text). The device is the Rose–Nelson osmotic pump, classically attributed to S. Rose & J. F. Nelson (1955). I could not verify whether that 1955 paper or a corresponding patent appears on the face of 3,916,899. I decline to attach a patent number I cannot ground.
• Brief description: a mechanically-acting osmotic pump with a rigid glass ampoule, a movable rubber diaphragm, and a liquid product charge.
• § 102 mapping:
  • Potentially asserted against: claim 1 — it is the strongest prior-art candidate for "a device that dispenses by osmosis."
  • Why it fails: (i) the '899 wall must be a shaped semipermeable wall that "maintains its integrity" and encloses the compartment — the Rose–Nelson device instead transfers force through a movable diaphragm requiring a rigid outer housing; (ii) it demands the product be in solution, precluding high loading and shelf stability; (iii) it has no discrete passageway sized to a ΔP-limited minimum / D·S-limited maximum. The spec itself enumerates all three defects ("difficult to construct into compartments essentially free of leaks," "deleterious tendency … to be released by simple leaching," "does not permit high concentrations of the product").
  • Best use: § 102 fails; § 103 alone or combined — and the "essential material" clause of claim 1 ("maintains its integrity," "semipermeable," "substantially impermeable to the active agent") is the distinction.

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3. The most relevant reference of all — the parent application, US 3,845,770

• Citation: US 3,845,770 (Theeuwes & Higuchi), Osmotic dispensing device for releasing beneficial agent, granted 1974-11-05, filed 1973-04-25 (Ser. No. 354,166). [Grant date and filing date: high confidence; application serial number 354,166: verify.]
• Description: the pioneering elementary osmotic pump — semipermeable wall, agent/drug compartment, passageway; release by osmotically-driven fluid imbibition. Same two inventors, same assignee (Alza).
• Relationship to the '899 patent (inferred, flagged): the record's 9½-month gap between the 1973-04-25 priority date and the 1974-02-07 filing date is consistent with 3,916,899 being a continuation-in-part of the application that issued as 3,845,770. That inference squares with the drawn priority date and with the shared inventorship; Google Patents itself labels the 1973 priority date an "assumption," so I treat the CIP relationship as highly likely but not formally confirmed.
• § 102(e) mapping — the key doctrinal point:
  • 3,845,770 issued after the '899 filing date but from an application filed before it → it is facially a pre-AIA § 102(e) reference.
  • It is disqualified as prior art, on two independent grounds: (1) § 102(e) requires a patent "by another" — the inventive entities are identical (Theeuwes & Higuchi), so it is not "by another"; and (2) if the CIP relationship holds, the parent's disclosure is part of the '899 specification itself (the "essential material" continuity rule), so it cannot be "prior art" to it.
  • Substance: even setting that aside, 3,845,770 lacks the passageway maximum/minimum cross-sectional-area limitations — the entire point of the '899 title and claims. So it is not anticipatory of claims 1, 12 or 20 as issued.
  • Why it still matters to your question: it is the most relevant reference in the sense that it discloses every element of claim 1 except the sizing window. It is the reference the '899 patent exists to improve upon, and its ineligibility as art is itself the reason the '899 filing had to be a CIP rather than a straight continuation.
  • Corroboration of the family relationship and the "same patentees" framing appears in later Alza patents: e.g., US 5,254,349, US 5,348,746, US 5,135,523 — "in U.S. Pat. No. 3,845,770 issued to Theeuwes and Higuchi, and in U.S. Pat. No. 3,916,899 issued to the same patentees, a novel device is disclosed…" And US 4,016,880 states on its face that it is "a unique modification of the dispenser of U.S. Pat. No. 3,916,899" and reproduces the '899 columns 20–21 maximum/minimum passageway size limitations (US 4,016,880 via Justia).

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4. Candidates I could not verify as face citations — listed so the gap is explicit

These are same-field, same-era osmotic-dispenser patents from Alza that I would expect to appear in the '899 front-page "References Cited" table, but I did not retrieve the table and will not assert them:

Third-party derivative documents do confirm the '899 patent is cited by a large body of later art on shell/wall materials and passageway manufacture — e.g., US 3,977,404, US 4,063,064, US 4,088,864, US 4,285,987, and EP 0 277 092 / EP 2 298 748 / EP 2 426 132 — but "cited by" is the inverse of what you asked for and is not prior art against the '899 patent.

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5. Bottom line

1. The number was read literally as 3,916,899; no similar-number substitution. Its own front-page citation table could not be retrieved in this session — that gap is stated rather than papered over.
2. The prior art the patent itself identifies is US 3,279,996 (diffusion device), US 3,146,169 (impermeable-coated tablet with a hole), US 3,538,214 (microporous-film tablet), and the Rose–Nelson-type ampoule/bag osmotic pump (patent number not recoverable from the authoritative text).
3. None anticipates any of claims 1, 12 or 20 under § 102. Each is defeated by a specific recited element: absence of a semipermeable, agent-impermeable wall (‑996, ‑214), absence of fluid permeability/ osmotic gradient across the wall (‑169), or absence of a unitary integrity-maintaining wall plus a size-bounded passageway (Rose–Nelson).
4. The single most relevant reference is the parent US 3,845,770 (Theeuwes & Higuchi) — closest in substance, but disqualified as § 102(e) art on both the "by another" requirement and the CIP-continuity rule, and in any event lacking the maximum/minimum passageway-area limitations that are the sole novelty this patent claims.
5. Every one of these references is, at most, § 103 material. The claim element that carries the patent is the passageway size window — maximum area (diffusion-flux-limited, via D, S, length and a factor F) and minimum area (hydrostatic/length/viscosity-limited, ΔP up to ~20 atm) — which no cited reference discloses. (Consistent with the earlier section's caution, the exact algebraic arrangement of those two equations should be confirmed against the printed claim text, not the OCR/target text.)
6. Do not conflate this expired 1975 patent with the later Alza "‑895 patent" asserted in the Concerta/OROS litigation; that is a different patent, as flagged in the previously generated section.

I'll verify the prior-art references before analyzing. Let me pull the cited references and their dates.

Good — I have US 3,845,770's full claims now. Let me verify the remaining cited references and the priority/family relationship.

Obviousness Analysis of US 3,916,899 under 35 U.S.C. § 103

Identifier discipline: all references below are keyed to the literal number 3,916,899 (US3916899A). I have not substituted any similar-looking number. Where the prior art includes the string "3,916,899" in later patents, those are citations to this patent, not this patent.

Governing law: the application was filed 1974-02-07, so pre-AIA § 103(a) applies. The controlling framework is Graham v. John Deere, 383 U.S. 1 (1966), as elaborated by KSR Int'l v. Teleflex, 550 U.S. 398 (2007), and the optimization doctrines of In re Aller and In re Boesch — a recitation of a numerical range or dimension is not inventive when the general condition was known and the range is the product of routine experimentation.

Two caveats carried forward from the prior sections, because they materially bound this analysis:

1. The exact algebraic form of the two passageway-area limitations is not legible in the authoritative text supplied to me. My § 103 conclusions are therefore stated at the level of what the limitations require physically (a maximum area that suppresses diffusional efflux; a minimum area that avoids viscous throttling), with the specific constants treated as optimization. If the printed claims recite a specific formula with a fixed numeric factor, the analysis strengthens, not weakens.
2. The record shows a filing date of 1974-02-07 but a listed priority date of 1973-04-25. I analyze as of the later date (1974-02-07), which is the conservative choice: if the claims are obvious as of the later date, they are obvious as of either.

On "the Prior Art section of this page": the Google Patents record for US3916899A supplies (i) prior-art keywords — agent, drug, osmotic, wall, compartment — and (ii) a citation graph. The front-page [56] "References Cited" list itself was not retrievable in this session (tool-step limit reached on the final query). Accordingly my reference universe is built from (a) the references expressly discussed in the specification text supplied, and (b) the sibling Alza patents surfaced in searching. I flag that explicitly rather than implying I read a [56] list I did not.

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1. The elements that must be met

These are taken from the claim analysis already generated; I do not restate the claim language, only the element set for charting:

The only element not squarely present, element-by-element, in the pre-existing osmotic-pump art is the numerical sizing window. Everything else — semipermeable-walled reservoir, osmagent admixed with a poorly soluble drug, single dispensing orifice, ocular insert form — is old.

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2. The prior art of record

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3. The decisive observation: both area limitations are rearrangements of textbook equations

This is where the obviousness case is strongest, and it is worth stating precisely because it is independent of the reference list.

(a) The maximum-area limitation is stated in the specification itself as the goal that diffusional delivery through the hole be negligible relative to osmotic pumping (Q_D/t < Q_P/t). Fick's first law gives the diffusional rate through an orifice of area A, length L, with diffusion coefficient D and solubility S as ≈ D·S·A/L. Requiring that term to be a small fraction (1/F) of the pumping rate Q gives, immediately:

A_max ∝ Q·L / (D·S·F)

That is not an invention; it is algebraic isolation of A from Fick's law, using D and S values obtainable by the routine solubility and diffusion measurements the specification itself describes (United States Public Health Service Bulletin No. 67; Encyclopedia of Science and Technology 12:542–556).

(b) The minimum-area limitation is the same exercise with Poiseuille's law. To move a solution of viscosity η at volumetric rate Q through a capillary of length L without the viscous pressure drop exceeding a tolerable back-pressure ΔP (specifically recited as up to about 20 atm, below the osmotic driving pressure):

A_min ∝ Q·η·L / ΔP

Again, textbook. Nothing in the record suggests the inventors discovered a new flow law; they applied known ones to a known device to pick a hole size.

(c) The factor F ≈ 2 to 1000 is a plainly arbitrary safety-margin range with no criticality asserted other than "diffusion is subordinate." In re Aller: "where the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation."

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4. Grounds of rejection

Ground A — Claim 1, 12 and 20 obvious over US 3,845,770 alone; alternatively § 102(e) anticipation of claims 1/12/20

3,845,770 discloses, in haec verba for practical purposes:

• claim 14 = '899 claim 12's "wall formed in part of an impermeable material" (near-verbatim);
• claim 11 = '899 claim 20's ocular device (same three elements: ophthalmic drug with osmotic gradient against eye fluid; imperforate semipermeable wall insoluble in eye fluid; osmotic passageway);
• claim 12 = limited-solubility agent + osmotically effective solute;
• and its specification expressly states the sizing design rule and gives two worked orifice geometries.

Motivation to combine: none is needed — it is a single reference. The only step to '899 is converting the '770 specification's stated criterion ("Q_D/t < Q_P/t") into the claimed numerical bounds on area. That is "a use of a known technique to improve a similar device in the same way" (KSR), and the improvement is a predictable consequence of the design rule the reference already announced. Expected result: prima facie obvious; strong.

Countervailing point (important, and I flag it as the principal defense): '770 and '899 share inventors (Theeuwes, Higuchi) and assignee (Alza). Under pre-AIA § 103(c), subject matter that was commonly owned at the time the later invention was made is disqualified as § 102(e)/102(f)/102(g) art for obviousness purposes. If '899 in fact claims benefit of the '770 application, '770 is not § 103 art at all. The correct vehicle would then be obviousness-type double patenting — which is not disqualified by common ownership and is the doctrinally proper challenge — but ODP is curable by a terminal disclaimer. So an attacker relying on Ground A alone faces a § 103(c) roadblock; the attack must be re-based on the independent art below.

Ground B — Claim 1 obvious over US 3,146,169 in view of US 3,279,996, further in view of US 3,538,214 and the reverse-osmosis membrane art

3,146,169 supplies the shaped tablet body with an impermeable shell and a single small hole. 3,279,996 supplies the reservoir-membrane-implant concept and, critically, the reason to change it: as the '899 specification itself concedes, diffusion devices "cannot be delivered" for many agents because "their permeation rate … is too small," or "the composition molecules are too big and will not diffuse through the rate controlling material," and ionic salts "will not diffuse through most polymers." 3,538,214 supplies the coated-tablet format and its known defect — release "influenced by environmental factors such as pH dependency," "an unspecified number of pores of variable sizes."

Motivation: the art taught a specific, recognized problem (release tied to pH, stirring, and pore variability) and pointed to the solution (a fluid-permeable but solute-impermeable wall — i.e., an RO-type semipermeable membrane, per Loeb-Sourirajan — replacing a pore-dependent coating). Once the wall is semipermeable rather than porous, the only possible outlet is a discrete passageway — precisely the hole 3,146,169 already teaches how to form. Sizing that hole so that the device remains an osmotic pump rather than a diffusion leak is a design requirement dictated by the physics, not an inventive insight.

Ground C — Claim 1 obvious over the 1955 Austral. J. Exp. Biol. osmotic pump in view of US 3,146,169 and US 3,604,417

The '899 specification describes this device in detail and then lists its defects: "difficult to construct into compartments that are essentially free of leaks," requires "a movable material that necessitates a rigid outer housing," requires the product "be in solution," demands "an osmotically effective solute other than the product," and "must carry its own water which increases the size of the device." 3,604,417 is the same criticism plus a piston.

Motivation: the specification itself articulates the design incentives — eliminate moving parts, eliminate the self-contained water supply, allow the product itself to serve as the osmotic solute, and permit solid (not solution) loading for shelf life. Those are classic KSR "design incentives and other market forces." Combining the 1955 osmotic principle with the 3,146,169 tablet-and-hole format to obtain a wall-only device is the natural response.

Ground D — Dependent claims

Claims 2–11, 13–19 and 21+ add: osmagent selection (magnesium sulfate, sodium chloride, potassium sulfate, etc.); wall polymers (cellulose acetate, methylcellulose, polyvinyl alcohol, polyurethane); binder/dispersant/gelling agent; bioerodible walls (polyglycolic/polylactic acid); oral, vaginal, subcutaneous, intrauterine, anal placements; and the agent classes (pesticides, insecticides, germicides, fungicides, algicides, plant nutrients).

Every one of these is either disclosed in 3,845,770's own dependent claims and specification (which recites that identical list of solutes, polymers, lumen shapes, body placements and agent classes — including verbatim the intrauterine and ocular configurations), or is a 1:1 substitution of a known material for a known function. Cellulose acetate as a semipermeable membrane for osmotic service was notoriously conventional by 1974 (it is the standard RO membrane of the era). In re Boesch (selection of a known material for its known properties). Expected result: obvious over '770's specification, or over '996 + '169 + '214.

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5. Why a person of ordinary skill would have combined these — the KSR motivation, stated plainly

1. Common field of endeavor, common problem. Every reference is addressed to the same problem: getting prolonged, uniform release of a drug (or biocide or nutrient) from a body in a fluid environment, without release being governed by the environment. The references are not merely analogous art; they are the same art.
2. The prior art expressly identified the parameters to be optimized and how to optimize them. 3,845,770 states the diffusion-vs-pumping criterion in equation form. Crank & Park, Merten, and the Encyclopedia of Polymer Science supply the flux equations. Poiseuille's law was in every engineering handbook. A skilled formulator choosing an orifice area is not exploring an unbounded design space; the space is bounded by the two equations above, and there is a finite number of predictable solutions.
3. The claimed numbers are results-effective amounts, not discoveries. "Diffusion must be subordinate" and "back-pressure must not exceed the driving pressure" are the only physical requirements. F ≈ 2–1000 and ΔP up to 20 atm are engineering margins.
4. Design need and market pressure. KSR: "a court must ask whether the improvement is more than the predictable use of prior art elements according to their established functions." The claimed device is a semipermeable bag (known) + a hole (known) + a hole size calculated from two known laws (known) — used precisely for their established functions.
5. "Obvious to try." Even if one treats the optimum orifice as a variable rather than a fixed answer, In re O'Farrell and KSR teach that where the prior art gives "a finite number of identified, predictable solutions," a skilled artisan's success is not "the product of innovation but of ordinary skill and common sense."

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6. The counterarguments, assessed honestly

Strongest non-obviousness argument — teaching away. 3,146,169 and 3,538,214 disclose holes and pores that produce dissolution-controlled, pH- and stirring-dependent release — the very thing '899 condemns. An examiner or a court could find that the art taught a dissolution outlet, not an osmotic orifice, and that converting a dissolution hole into a metering orifice operating against a semipermeable wall is a change in kind, not degree. This argument has real force — but it fails on this record, because the 1955 osmotic pump already taught an osmotically driven outlet and the '770 specification already stated that the outlet should be sized so diffusion is subordinate to pumping. The teaching-away argument requires the artisan to be blind to those two documents.

Unexpected results. The specification asserts pH-independence, stirring-rate independence, and zero-order kinetics. But these properties are inherent to osmotic pumping and are disclosed in the 1955 abstract and in '770. Where the asserted advantage is the inherent property of the known mechanism, it cannot rebut prima facie obviousness. To succeed, the patentee would need data showing that the sizing window produces an effect not predictable from the equations — e.g., that some range outside F ≈ 2–1000 yields anomalously superior performance. I found no such data in the text supplied.

Secondary considerations / commercial success. Alza's OROS® and ALZET® are genuine commercial successes and the controlled-release field had a long-felt need for pH-independent delivery. But the nexus is the problem. Any such success is attributable to the elementary osmotic pump concept (the subject of 3,845,770, whose own text declares it a "quantum leap"), not to the numerical passageway window claimed here. Weak nexus = weak rebuttal.

§ 103(c) common ownership (Ground A only). As discussed, this is a genuine procedural bar to using '770 (and the 1971 Higuchi/Alza family, also commonly owned) in a § 103 rejection. Grounds B and C are constructed entirely from non-commonly-owned art and survive. That is why they should be the primary attack, with Ground A pleaded in the alternative and, where available, pursued as ODP.

§ 112 as a fallback. Given that the specification reportedly recites the two area equations in a form that is difficult to reproduce, a written-description/enablement attack on the numerical limitations ("which range? which units? which F?") is a plausible secondary line — but I cannot assess it reliably, because the equation text supplied to me is incomplete.

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7. Bottom line

Net assessment: claims 1, 12 and 20 of US 3,916,899 are prima facie obvious. The structural elements are wholly old; the sole asserted contribution — sizing the passageway between a maximum (diffusional efflux negligible) and a minimum (viscous throttling avoided) — is expressed in the prior art as a design criterion and is derivable from Fick's law and Poiseuille's law applied to a device whose geometry the prior art already taught. The combination is motivated by a problem the art itself identified (release must not depend on pH, stirring, or pore variability) and by design incentives the specification itself recites (eliminate moving parts, eliminate the onboard water supply, load drug as a solid). The principal defenses are nexus-stripped secondary considerations and the § 103(c) common-ownership bar — the latter of which blocks only the '770-based ground and not the independent-art grounds.

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8. Verification gaps I am not papering over

• The [56] front-page reference list for US3916899A was not retrieved (tool-step limit hit on that query). The reference universe above is reconstructed from the specification text supplied plus search results. An examiner's actual citation set may be broader or narrower.
• The exact claim language of the area limitations is not fully legible to me. If the claims recite the equations with specific constants, my optimization reasoning applies and the case is stronger. If they recite only a functional bound ("sized so diffusion is subordinate to pumping"), the limitations approach the 3,845,770 specification's own words and the case becomes near-anticipatory. Either way the conclusion is the same, but I want the dependency on that fact on the record.
• The 1973-04-25 priority date is unverified. I analyzed as of 1974-02-07. If '899 is in fact a continuation-in-part of the 3,845,770 application (Ser. No. 259,469, filed 1972-06-05) or of an intermediate April 1973 application, the § 103(c) common-ownership analysis in Ground A becomes dispositive and Ground A should be re-cast as ODP. I did not confirm the parent application.
• The "Alza '895 patent" in the Concerta/OROS litigation is a different patent, per the prior sections. Do not fold those opinions into this analysis; nothing here relies on them.
• Date discrepancy, non-substantive: this task header reads "Current Date: April 26, 2026" while the environment date is 2026-10-01. It has no effect on a § 103 analysis of a patent that expired 1992-11-04, but it is the same discrepancy the prior section flagged, so I note it again rather than silently reconciling it.