STABILITY AND NEW FORMULATIONS OF HEXETID INE .2. FORMULATIONS AND IN-VITRO AVAILABILITY

The solubilization of the water insoluble antimicrobial compound hexet idine is achieved by tensides and cyclodextrins. Using tensides the ac tive ingredient is associated with the lipophilic part of the emulsifi er. Tensides with a hydrophilic element in the lipophilic part of the molecule show better solubilizing properties. In contrast a higher sta bility is achieved with emulsifiers without hydrophilic elements in th e lipophilic part of the molecule. The antimicrobial activity, determi ned by an in vitro test, is not influenced by the type of emulsifier. Cyclodextrines form inclusion complexes with hexetidine. Hydroxy propy l-beta-cyclodextrine is preferred due to its high water solubility. Th is inclusion complex shows compared with tenside solibilization a bett er taste and stability. The in vitro antimicrobial activity was compar able to tenside solubilized products.