[Stability and new formulations of hexetidine. 2. Formulations and in vitro bioavailability]

The solubilization of the water insoluble antimicrobial compound hexetidine is achieved by tensides and cyclodextrins. Using tensides the active ingredient is associated with the lipophilic part of the emulsifier. Tensides with a hydrophilic element in the lipophilic part of the molecule show better solubilizing properties. In contrast a higher stability is achieved with emulsifiers without hydrophilic elements in the lipophilic part of the molecule. The antimicrobial activity, determined by an in vitro test, is not influenced by the type of emulsifier. Cyclodextrins form inclusion complexes with hexetidine. Hydroxy propyl-beta-cyclodextrin is preferred due to its high water solubility. This inclusion complex shows compared with tenside solubilization a better taste and stability. The in vitro antimicrobial activity was comparable to tenside solubilized products.