Zinc pyrithione

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Zinc pyrithione
Systematic (IUPAC) name
bis(2-pyridylthio)zinc 1,1'-dioxide
Identifiers
CAS number	13463-41-7
ATC code	D11AX12
PubChem	26041
Chemical data
Formula	C₁₀H₈N₂O₂S₂Zn
Mol. mass	317.705
Pharmacokinetic data
Bioavailability	?
Metabolism	?
Half life	?
Excretion	?
Therapeutic considerations
Pregnancy cat.	?
Legal status	OTC (US)
Routes	Topical

Zinc pyrithione (abbreviated ZnP and also known as pyrithione zinc) is an antifungal agent best known for its use in treating dandruff and seborrheic dermatitis. It also has antibacterial properties and is effective against many pathogens from the streptococcus and staphylococcus class. Other medical uses involve treatment of psoriasis, eczema, ringworm, fungus, athletes foot, dry skin, atypical dermatitis, tinea, vitiligo, etc.

Due to its low solubility in water (8 ppm at neutral pH), zinc pyrithione is suitable for use in outdoor paints and other products that provide protection against mildew and algae. It is an effective algaecide. It is chemically incompatible with paints relying on metal carboxylate curing agents. When used in latex paints and the water contains high amount of iron, a sequestering agent that will preferentially bind the iron ions is needed. Its decomposition by ultraviolet light is slow, providing years of protection even against direct sunlight.

Its antifungal effect most likely lies in the ability of an un-ionized pyrithione molecule to disrupt membrane transport by blocking the proton pump that energizes the transport mechanism (Carol J. Chandler and Irwin H. Segel at [1]). Fungi are capable of inactivating pyrithione in low concentrations.

It is known under trade name zinc OMADINE.

It was first synthesized in the 1930s [2] [3].

The chemical name is zinc bis(pyridine-N-oxide-2-thiolate), or also bis(1-hydroxy-2(1H)-pyridinethiolato-O,S) zincate. It has the empirical formula C₁₀H₈N₂O₂S₂Zn and a more descriptive formula (C₅H₄NO-2-S)₂Zn. It features two pyridine-derived chelating ligands bound to zinc via their oxygen and sulfur atoms.

Zinc pyrithione is approved for over-the-counter topical use in the United States as a treatment for dandruff. It is the active ingredient in several anti-dandruff shampoos such as Head & Shoulders. However, in its industrial forms and strengths, it may be harmful by contact or ingestion.