aluminum chloride hexahydrate aluminum chloride hexahydrate aluminum chloride hexahydrate, sold under the brand name hydrosal gel among others, is a first-line treatment for excessive sweating. clinical studies support the efficacy and low incidence of irritation of the 15% aluminum chloride and 2% salicylic acid gel base formula. formulations hydrosal gel is a registered trademark of valeo pharma inc. hydrosal gel contains 15% aluminum chloride|aluminum chloride hexahydrate, an ingredient often used in strong antiperspirants, as well as a hydroalcoholic salicylic acid gel base.