Solubility Properties of Chlorhexidine Salts

Chlorhexidine (CHX) is effective in treating oral bacterial infections. The solubility was shown to be highly dependent on the salt present in solution. Gluconate enhances the amount of CHX diacetate in solution possibly through mixed micelles formation, because the solubility product is such that the concentration of CHX will exceed the critical micelle concentration. However, only low concentrations of CHX dichloride can be obtained, which is not appreciably solubilized by gluconate ions. The low concentration of CHX that can be achieved in physiological concentrations of chloride in the oral cavity may be problematic for dental, slow release formulations.