1938 Earl W. Flosdorf et al.'s 'Biological Apparatus, Container, and Method' US2388134A — Reading Lyophilization Back from WWII Plasma-Drying to Modern Biologics
About these "memos": Memos in this series record a candidate at the stage where the primary-source URL has been verified. This memo includes Claim 1, inventors, dates, and assignee from Google Patents, but the full specification (drawings, examples, the WWII plasma-drying program documents) has not been read end-to-end. Confirmed facts only; inferences are flagged as such.
Why dig here
Lyophilization (freeze-drying) underpins a wide range of modern technology: (a) instant foods (freeze-dried miso soup, instant coffee), (b) space and expedition food, (c) biologics stabilization (vaccines, monoclonal antibodies, insulin), and (d) long-term plasma and serum storage. The starting point is the December 1933 first-ever lyophilization of human serum at the University of Pennsylvania by Stuart Mudd and Earl W. Flosdorf. Flosdorf then partnered with F.J. Stokes Machine Co. — a Philadelphia maker of vacuum pumps and packaging machinery — to patent commercial apparatus. US2388134A is a representative patent on that line: Claim 1 covers a sublimation-drying machine using a regenerable chemical desiccant and vacuum. The point is to verify, from primary sources, the link from the WWII plasma-drying program (Sharp & Dohme mass production for combat transfusion) to modern biologics manufacturing.
Patent essentials
- Patent: US2388134A
- Title: Biological apparatus, container, and method
- Filed: 1938-07-18
- Granted: 1945-10-30
- Inventors: Earl W. Flosdorf; Charles J. Westin; Francis Joseph Stokes Jr.; Edith Wolfrom Westin (four co-inventors)
- Original assignee: Stokes Machine Co. (Philadelphia, Pennsylvania — F.J. Stokes's vacuum-pump and packaging-machinery company)
- Current assignee: FJ Stokes Machine Co. (corporate succession)
- Primary source: Google Patents (URL confirmed; Claim 1 retrieved)
Claim 1 (verbatim)
An apparatus providing means for treating biological material for preservation by dehydrating through the action of a regenerable chemical desiccant and vacuum and for regenerating the desiccant comprising, a desiccant chamber, a solid, porous, regenerable chemical desiccant within said chamber, a plurality of outlets communicating with said chamber and suitable for use as container connectors, a plurality of outlet valves each located at an angle of approximately 45 above horizontal and associated with one of said outlets so as to control the communication of said outlet with said chamber, and vacuum-producing means communicating with said chamber for the removal of air.
Five components claimed:
- Desiccant chamber
- Solid, porous, regenerable chemical desiccant — absorbs water vapor and is regenerated by heating, allowing repeated industrial use
- Multiple outlets suitable as container connectors — connecting plasma vials and similar containers in parallel
- Valves at approximately 45° above horizontal — outlet control
- Vacuum-producing means — removing air from the chamber
The design pivot is the regenerable desiccant, which makes the apparatus run as a continuous industrial process — the defining property of a commercial lyophilizer.
Biomedical context (1933–1945)
| Year | Event | Source type |
|---|---|---|
| 1906 | Bordas / d'Arsonval (France) — proof-of-concept low-temperature vacuum drying | Secondary (lyophilization-history aggregations) |
| 1933-12 | Stuart Mudd & Earl W. Flosdorf (U. Penn) — first lyophilization of human serum | Secondary (PSU public articles) |
| 1935 | Flosdorf & Ronald I. N. Greaves — first commercial lyophilizer | Secondary (lyophilization-history aggregations) |
| 1938-07-18 | US2388134A filed (Flosdorf + Stokes co-filing) | Primary (Google Patents) |
| 1940-1945 | WWII plasma-drying program: Sharp & Dohme mass-produces dried plasma for forward field hospitals | Secondary (PSU and US Army medical-history aggregations) |
| 1945-10-30 | US2388134A granted | Primary (Google Patents) |
The grant date (Oct 30 1945) is two months after the end of WWII, so the wartime plasma-drying experience may have factored into late-stage examination — speculation, not verified.
Modern resonance
| US2388134A (1938) | Modern (2026) | Verdict |
|---|---|---|
| Chemical desiccant + vacuum sublimation drying | Pharmaceutical lyophilization (parts of Pfizer mRNA-vaccine production lines, monoclonal-antibody formulations, insulin stabilization) | Same (sublimation + vacuum principle is preserved; chemical desiccants have been replaced by cooled condensers) |
| Field-use dried plasma for combat transfusion | Modern dried plasma for emergency / disaster medicine (French military FLYP, US military Plasma Lyo) | Same (use case and design ethos both preserved) |
| Long-term preservation of biological material | Freeze-dried foods (instant coffee, space food, expedition food, miso soup) | Similar (same principle, scope expanded from biomedicine to food) |
| Continuous-operation design with regenerable desiccant | Modern continuous lyophilizers (Telstar, Syntegon, etc.) | Similar (continuous-operation problem framing is preserved; the mechanism shifted to refrigerated condenser + vacuum pump systems) |
| 1938 apparatus claim | 2020s pharmaceutical-lyophilization validation (PAT, real-time monitoring) | Metaphor (cross-era genealogy; apparatus design and modern quality assurance sit in different contexts) |
"Same" rows assert direct succession of design ethos / use case; "similar" rows share problem framing while differing in implementation; "metaphor" rows are cross-era genealogies.
Pitfalls
Pitfall 1: don't reduce lyophilization to "Flosdorf as inventor" Lyophilization had precedents — Bordas–d'Arsonval 1906, Shackell 1909, Tival 1927 — and Flosdorf is best read as the commercialization origin, not the original inventor. This memo limits its claim to "a representative patent on commercial lyophilizers."
Pitfall 2: candidates.tsv entry is vague — "multiple inventors; multiple patents in 1920s–1930s" The DB does not point at any specific patent number, and the URL it does list (US1986039) is an adhesive-application apparatus — completely unrelated, corrected during Day 15. This memo selects Flosdorf's representative patent US2388134A, but that does not make it "the unique origin patent for lyophilization." Flosdorf himself filed many adjacent patents, and a comparison with the F.J. Stokes Corp assignee patent family is required.
Pitfall 3: handling of "Sharp & Dohme" The standard freeze-drying narrative says "Sharp & Dohme mass-produced dried plasma during WWII," but this patent is assigned to Stokes Machine Co.; the IP relationship with Sharp & Dohme cannot be confirmed from this patent alone (Flosdorf's individual consultancy connection to Sharp & Dohme is secondary-source only). This memo flags that distinction.
Open items
- Full specification (drawings, examples, continuous-operation conditions) verbatim
- Records of this apparatus actually being used in the WWII plasma-drying program
- Details of any contract relationship between Flosdorf and Sharp & Dohme
- Forward citations and links to modern lyophilizer patents
- F.J. Stokes Machine Co. corporate history and any commercial-license records for this patent
- Verbatim from Flosdorf's Freeze-Drying: Drying by Sublimation (book, 1949)
- Patent numbers for Bordas–d'Arsonval 1906, Tival 1927, Elser 1934, and side-by-side comparison with this patent
Next moves
When this gets upgraded from memo to note, retrieve (a) the full specification and apparatus-drawing analysis, (b) the WWII plasma-drying program archives (US Army medical-history archives), (c) the Flosdorf–Sharp & Dohme contractual relationship, (d) the full Flosdorf-related patent set under F.J. Stokes Corp assignee, (e) modern pharmaceutical-lyophilization validation regimes (FDA, ICH Q1A–E) — to map the first-generation IP of commercial lyophilization technology. Day 14 ep54's cisplatin formulation patent US4310515A and its "lock down a public-domain compound on a different layer" pattern is a useful comparison frame.
References:
- Original patent: US2388134 on Google Patents
- Food & Health Patents Note #5: Glyphosate-tolerant GMO US4535060A
- Food & Health Patents Memo #6: Flavr Savr US4801540A
- Food & Health Patents Memo #7: Margarine US146012A
- Wikipedia: Freeze-drying (https://en.wikipedia.org/wiki/Freeze-drying)
- Pennsylvania Center for the Book: Earl W. Flosdorf (http://pabook.libraries.psu.edu/)