CS-010 Sansho Pharma Kojic Acid Skin-Whitening Origin Patent Number Identification Hits the J-PlatPat Direct-Access Wall — An 'Information Wall' Excavation: The 13-year Period (1975 Tyrosinase-Inhibition Discovery → 1988 World-First Quasi-Drug Skin-Whitening Active Approval) Has JP Patents (Tokukohsho / Tokukaisho) Whose Publication Numbers Cannot Be Identified From Public Web Resources

About This Excavation Memo

The existence of a primary-source URL has been confirmed, but the body remains unread and Claim 1 verbatim is not yet retrieved. The number JP S58-118507 handed off from Day 21 is in fact Lion Corp's 'transparent toothpaste' patent — a complete number mix-up. As of Day 22, the correct origin patent number for Sansho Pharma kojic acid could not be identified from public web resources. This memo records the discovery itself: the origin patent number lies behind an information wall. Confirmation requires interactive J-PlatPat search or a direct inquiry to Sansho Pharma.

Why Excavate This?

We executed Day 22 hand-off recommendation #2: 'verify CS-010 Sansho Pharma JP S58-118507 in J-PlatPat (Japanese language).' We pulled JP S58-118507 (=JPS58118507A) from Google Patents. The title is 'Transparent Toothpaste,' the applicant is Lion Corp, the inventors are Uematsu Michio / Ichikawa Hiromichi (two co-inventors). The patent describes a toothpaste containing silica abrasive and a fatty-acid diethanolamide for astringency suppression. It has nothing to do with Sansho Pharma, kojic acid, or whitening. The number JP S58-118507 handed off from Day 21 is the same kind of mix-up as CS-007 / CS-008.

We then tried to identify the correct Sansho Pharma kojic acid origin patent number from public web resources, surveying (1) Sansho Pharma's official history page (sansho-pharma.com/about/history), (2) Kose's research report (after redirect to koseholdings.co.jp/ja/kose/research/secretstory/kojicacid), (3) Dermed's research report (dermed.jp/store/s/technology/kojicacid), (4) ja.wikipedia kojic acid article, (5) Sansho Pharma's beauty-ingredient lab series 'History of Whitening in Japan.' None of the five public resources list any origin patent publication number (Tokukohsho / Tokukaisho). We could only confirm the public history timeline.

Patent Basic Info (the mix-up number Day 21 handed off)

Item	Content
Number (mix-up)	JP S58-118507 (=JPS58118507A)
Actual content	'Transparent Toothpaste' — silica abrasive + fatty-acid diethanolamide for astringency suppression
Applicant	Lion Corp (not Sansho Pharma)
Inventors	Uematsu Michio / Ichikawa Hiromichi (two co-inventors)
Filing	1982-01-06
Disclosure	1983-07-14
Legal status	Pending
Relation to Sansho Pharma / kojic acid	None (complete mix-up)

Confirmed public-history timeline of Sansho Pharma kojic acid:

1975: Sansho Pharma discovered tyrosinase inhibition (melanin-synthesis enzyme suppression) of kojic acid. Researcher names not in public resources
1980s: 13 years of R&D. Patent numbers filed during this period not identifiable from public resources
1988: Approved by the then-MHW (Ministry of Health and Welfare) as Japan's first quasi-drug whitening active. World's first kojic-acid-formulated cream launched
1990: Kose launched 'Kose Whitening Cream XX' (per Kose's research report)
March 2003: MHLW issued a notice temporarily suspending kojic acid use in quasi-drugs (mutagenicity concern)
2005-11-02: Additional safety tests showed no problem; the suspension was lifted

Claim 1 (Not Retrieved)

Claim 1 verbatim of the Sansho Pharma kojic acid origin patent is not retrieved in this memo. J-PlatPat direct access is JS-heavy / authenticated for WebFetch, blocking retrieval. The five public resources surveyed (ja.wikipedia kojic acid, Sansho Pharma, Kose, Dermed) do not list the origin patent number. The very identification of the origin patent lies outside the public web layer — that is the central finding of this memo.

Modern-Day Connection (Conjecture)

Three speculative explanations for why the Sansho Pharma kojic acid origin patent number is hard to identify from public web resources:

Historical non-disclosure culture of the applicant: Sansho Pharma may not have disclosed the kojic-acid patent family tree on the web as a corporate cultural pattern since founding. This was a tendency among Japanese chemical and cosmetic manufacturers up to the 1990s; non-compete clauses in contracts with licensees (Kose, Sunstar, etc.) may indirectly suppress patent-number web disclosure
Aftermath of the 2003 quasi-drug-use suspension: After the 2003 MHLW notice temporarily suspended kojic-acid quasi-drug use over mutagenicity concerns, official PR may avoid emphasizing the origin patent number to not re-litigate the history
Tokukohsho / Tokukaisho searchability wall: The 1975-1988 origin patents should be issued under 'Tokukohsho' (publication-after-examination) or 'Tokukaisho' (early publication). These older JP publication-number systems are exhaustively retrievable only via interactive J-PlatPat search; Google Patents' JP coverage centers on the 1990s onward, with thin indexing for the 1980s Tokukohsho / Tokukaisho

Of these three, (3) is a technical fact; identifying the origin patent number requires interactive J-PlatPat search filtered by applicant 'Sansho Pharma Co., Ltd.'.

Unverified

Sansho Pharma kojic acid origin patent publication number (Tokukohsho / Tokukaisho)
Claim 1 verbatim
Researcher names of the 1975 tyrosinase-inhibition discovery (not identifiable from public resources)
Details of the licensing agreements between Sansho Pharma and Kose / Sunstar / other licensees
Primary source of the efficacy and safety data submitted to MHW for the 1988 quasi-drug approval
Primary source of the additional tests behind the 2003 MHLW suspension and 2005 lift

Next Actions

Interactive J-PlatPat search: filter by applicant 'Sansho Pharma Co., Ltd.', filing date 1975-1988, related classification (C07D309/30 etc.) for exhaustive retrieval. J-PlatPat does not require authentication but is JS-heavy; either Haruko queries the browser directly, or a future session retrieves via Playwright
Direct inquiry to Sansho Pharma R&D: request the origin patent number disclosure via official PR / R&D PR
Identify alternative origin candidates: search J-PlatPat exhaustively for kojic-acid related patents from non-Sansho-Pharma applicants (licensee filings such as Kose / Sunstar, or the earliest filings related to the 1907 Saburo Sawamura kojic-acid discovery)
Position of this memo: as the first installment of the third form (information wall) of cosmetic-subseries DB reliability problems (mix-up / catchphrase misreading / information wall). Read alongside Day 22 ep79 (misreading) and ep81 (absence)