Aluminum Zirconium Pentachlorohydrate is a chemical compound predominantly used in antiperspirants. It is formulated to reduce perspiration and manage body odor by forming a gel-like plug in the sweat ducts, which temporarily blocks the release of sweat.

Chemical Composition and Structure

The chemical composition of Aluminum Zirconium Pentachlorohydrate includes:

• Aluminum (Al): A metal element that contributes to the formation of the gel-like plug in sweat ducts.
• Zirconium (Zr): A metal that enhances the stability and effectiveness of the aluminum-based complex.
• Chlorine (Cl): Chlorine atoms are integrated into the complex to ensure its stability and efficacy.
• Water (H₂O): Present as a hydrate, it helps dissolve the complex and facilitate its application.

Structurally, Aluminum Zirconium Pentachlorohydrate consists of aluminum and zirconium salts complexed with chlorine and water. This combination forms a stable gel when in contact with sweat, creating a barrier that reduces sweat production.

Physical Properties

• Appearance: Typically a white crystalline powder or an opalescent gel when dissolved.
• Solubility: Soluble in water, forming a clear solution.
• pH: Slightly acidic, with a pH range of approximately 3.5 to 4.5 in solution.
• Melting Point: High melting point, contributing to its stability in various formulations.
• Stability: Chemically stable under normal storage conditions and resistant to degradation.

Production Process

• Synthesis: Production begins with the reaction of aluminum salts with zirconium salts in the presence of chlorine and water. This process forms a basic aluminum-zirconium-chlorine-hydrate complex.
• Complex Formation: The mixture is then treated to ensure proper hydration and stabilization, resulting in a stable gel or solution.
• Purification: The complex is purified to remove any residual salts, unreacted components, and other impurities. This is achieved through filtration and crystallization processes.
• Formulation: The purified complex is incorporated into antiperspirant formulations. It is combined with other ingredients such as emulsifiers and stabilizers to create a final product suitable for consumer use.

Applications

• Medical: While primarily used in personal care products, it may have applications in medical formulations where sweat control is necessary, though its use in this domain is less common.
• Cosmetics: The most common use of Aluminum Zirconium Pentachlorohydrate is in over-the-counter antiperspirants and deodorants. It effectively reduces sweat production and helps manage body odor.

INCI Functions:

Antiperspirant. Controls both sweat and body odour by preventing sweat from reaching the stratum corneum with a preventive bactericidal action. If sweat has just reached the epidermal surface, it creates a temporary agglomeration on the sweat gland that will be removed by washing.

Cosmetic astringent. This ingredient exerts a direct effect on the skin by tightening dilated pores by contracting stratum corneum cells and removing superfluous oil.

Deodorant agent. When substances that give off an unpleasant odour are included in cosmetic formulations (typical examples are methyl mercaptan and hydrogen sulphide derived from garlic), deodorants attenuate or eliminate the unpleasant exhalation.

CAS   98106-54-8

EC number   308-575-2

Cosmetic safety

Restricted cosmetic ingredient as III/50 a Relevant Item in the Annexes of the European Cosmetics Regulation 1223/2009. Substance or ingredient reported: Aluminium zirconium chloride hydroxide complexes AlxZr(OH)yClz and the aluminium zirconium chloride hydroxide glycine complexes. 

Maximum concentration in ready for use preparation 20% (as anhydrous aluminium zirconium chloride hydroxide) 5.4% (as zirconium).

The ratio of the number of aluminium atoms to that of zirconium atoms must be between 2 and 10 2. The ratio of the number of (Al+Zr) atoms to that of chlorine atoms must be between 0.9 and 2.1 3. Not to be used in aerosols dispensers (sprays).