Undecylenic Acid
| Evidence Level: L4 | Predicted Indications: 10 |
Table of Contents
- Undecylenic Acid
- Undecylenic Acid: From Tinea Pedis and Tinea Corporis to Dermatophytosis of the Groin and Perianal Area
Undecylenic Acid: From Tinea Pedis and Tinea Corporis to Dermatophytosis of the Groin and Perianal Area
One-Sentence Summary
Undecylenic acid is a topical fatty-acid antifungal, originally used for tinea pedis, tinea corporis and other tinea infections. The TxGNN model predicts it may be effective for dermatophytosis of the groin and perianal area (tinea cruris). There are currently 0 clinical trials and 0 publications specific to this site, so the support is model prediction and mechanistic reasoning only.
Quick Overview
| Item | Content |
|---|---|
| Original Indication | Tinea pedis, tinea corporis, tinea infection (the Singapore licence record contains no approved indication text) |
| Predicted New Indication | Dermatophytosis of groin and perianal area |
| TxGNN Prediction Score | 99.94% |
| Evidence Level | L4 |
| Singapore Market Status | ✓ Marketed |
| Number of Registrations | 1 |
| Recommended Decision | Hold |
Why is This Prediction Reasonable?
Currently, detailed mechanism of action data is not available. Based on known information, undecylenic acid is a topical fatty-acid antifungal. Its efficacy in tinea pedis and tinea corporis is the basis of its original use, and mechanistically it may be applicable to other dermatophyte infections of the skin.
Tinea cruris is a dermatophyte infection of the same class as the original indications. The causative organisms and the superficial skin location are very similar, so activity in the groin is plausible by extension. The very high TxGNN score (0.999) most likely reflects this close similarity to the approved indications. It is not independent clinical evidence.
Other predicted indications (all Hold or Research Question)
| Rank | Predicted Indication | Score | Evidence Level | Comment |
|---|---|---|---|---|
| 2 | Majocchi granuloma | 99.08% | L5 | Deep follicular infection; topical penetration is poor and systemic therapy is usually needed |
| 3 | Ectothrix infectious disease | 99.08% | L5 | Hair-shaft infection related to tinea capitis; usually needs systemic therapy |
| 4 | Endothrix infectious disease | 99.03% | L5 | Spores inside the hair shaft are hard to reach topically |
| 5 | Dermatophytosis of scalp or beard | 99.02% | L4 | Only a 1956 historical report on a combination product; systemic therapy is the standard |
| 6 | Pityriasis versicolor | 99.01% | L5 | Caused by Malassezia yeast, not dermatophytes; speculative |
| 7 | Superficial mycosis | 99.01% | L4 | Broad category largely overlapping the approved indications; categorised as a Research Question |
| 8 | Cutaneous candidiasis | 98.90% | L4 | In vitro activity against Candida has been reported, but the one retrieved paper concerns a different drug |
| 9 | Tinea profunda | 98.77% | L5 | Deep infection; topical use is unlikely to reach effective concentrations |
| 10 | Tinea manuum | 95.87% | L4 | Closely related to tinea pedis, but only indirect evidence |
Clinical Trial Evidence
Currently no related clinical trials registered.
Literature Evidence
No publication directly supports the top prediction (tinea cruris). The publications retrieved for other predicted indications are listed below. None of them can be confirmed as direct efficacy evidence for undecylenic acid.
| PMID | Year | Type | Journal | Key Findings |
|---|---|---|---|---|
| 42334914 | 2026 | Review / clinical recommendation | Ceska a Slovenska farmacie | Over-the-counter treatment of foot mycoses (tinea pedis) based on clinical recommendations (relevant to superficial mycosis) |
| 28906086 | 2017 | Formulation / review (type unconfirmed) | Giornale italiano di dermatologia e venereologia | New topical formulation for onychomycosis; discusses the limited permeability of the nail plate (relevant to superficial mycosis) |
| 13371368 | 1956 | Historical clinical report (likely uncontrolled) | Southern Medical Journal | Salundek ointment and lotion (a combination product) for tinea capitis due to Microsporum audouini; design and outcomes unknown |
| 14275504 | 1965 | Early clinical report on a different drug | Archives of Dermatology | About tolnaftate, not undecylenic acid (relevant to cutaneous candidiasis) |
Singapore Market Information
| Authorization Number | Product Name | Dosage Form | Approved Indication |
|---|---|---|---|
| SIN09862P | VETIC CREAM | Cream | Not stated in the licence record |
Undecylenic acid is registered in Singapore as a single-ingredient topical cream (one valid licence, none cancelled). The manufacturer is Sato Pharmaceutical Co Ltd.
Safety Considerations
Please refer to the package insert for safety information. No drug interaction records were found for undecylenic acid in the data compiled for this report.
Conclusion and Next Steps
Decision: Hold
Rationale: The top prediction, tinea cruris, is mechanistically reasonable because it is a dermatophyte infection of the same type as the original indications. However, no trials or site-specific publications support it, and the high TxGNN score probably reflects similarity to the approved indications rather than new evidence. The deeper or hair-based infections in the list are unlikely to respond to a topical fatty acid.
To proceed, the following is needed:
- The package insert for the Singapore product (VETIC CREAM), to confirm the approved indications, warnings and contraindications
- Mechanism of action data for undecylenic acid
- Site-specific efficacy data for tinea cruris, ideally from controlled trials
- Confirmation of whether tinea cruris is already covered by the current labelled use ("tinea infection"), which would reduce the added value of a repurposing claim
- Direct evidence for any other candidate indication, such as cutaneous candidiasis or tinea manuum, before considering it further
Disclaimer
This content is for research purposes only and does not constitute medical advice. Clinical validation is required before any clinical application.