Zinc Pyrithione (ZnPT) CAS 13463-41-7

Zinc Pyrithione (ZnPT) – Antifungal and Antibacterial Agent for Cosmetics and Paints

Basic Information

• CAS Number: 13463-41-7

• Molecular Formula: C₁₀H₈N₂O₂S₂Zn

• Molecular Weight: 317.70 g/mol

• Appearance: White to off-white crystalline powder

• Solubility: Practically insoluble in water; soluble in dimethyl sulfoxide (DMSO) and some organic solvents

• Stability: Stable under normal conditions; decomposes on exposure to light and heat

Overview
Zinc pyrithione (ZnPT) is a coordination complex of zinc with pyrithione. It is widely recognized for its potent antifungal and antibacterial properties, making it a popular active ingredient in cosmetic, pharmaceutical, and industrial applications. Its ability to disrupt microbial cell membranes and interfere with essential metabolic processes ensures effective control of a broad spectrum of microorganisms.

Mechanism of Action
ZnPT acts by chelating metal ions and disrupting the electrochemical gradient across microbial cell membranes, leading to cell lysis and death. It also inhibits fungal growth by interfering with the synthesis of ergosterol, a key component of fungal cell membranes. Its activity is particularly pronounced against the yeast Malassezia (formerly Pityrosporum), which is associated with dandruff and seborrheic dermatitis.

Applications

• Hair care: Used in anti‑dandruff shampoos, conditioners, and scalp treatments to control flaking and itching.

• Skin care: Incorporated into creams, lotions, and soaps for its antifungal and antibacterial benefits.

• Cosmetics: Added to makeup and other personal care products as a preservative and antimicrobial agent.

• Paints and coatings: Employed as an antifouling and antimicrobial additive in marine and industrial coatings to prevent mold, mildew, and algae growth.

• Medical: Used in topical antifungal preparations for skin infections.

Key Benefits

• Broad‑spectrum efficacy against fungi, bacteria, and some viruses.

• Effective at low concentrations (typically 0.1–1% in shampoos; 0.01–0.1% in cosmetics).

• Long‑lasting residual activity.

• Good compatibility with many formulation ingredients.

• Stable when stored in opaque, airtight containers away from light.

Safety and Regulatory

• Zinc pyrithione is approved for use in cosmetics and over‑the‑counter products in many countries (including the US, EU, and Japan) at specified maximum concentrations.

• In shampoos, typical concentrations are 0.5–1.0% (for dandruff control).

• May cause mild skin irritation or sensitization in some individuals; patch testing recommended for leave‑on products.

• Avoid contact with eyes; if contact occurs, rinse thoroughly with water.

• Not recommended for use on broken or irritated skin.

• Handle with appropriate personal protective equipment (gloves, safety goggles) to avoid inhalation and skin contact.

Handling and Storage

• Store in a cool, dry, well‑ventilated area, away from direct sunlight, heat, and strong oxidizers.

• Keep containers tightly sealed to prevent moisture absorption and degradation.

• Shelf life: typically 24 months under recommended conditions.

Packaging
Available in 1 kg, 5 kg, 25 kg drums, and custom packaging upon request.

Quality Assurance
Each batch is tested for purity (by HPLC), zinc content, and antimicrobial activity to ensure consistent quality.