[Crystalline molecular complexes generated between surfactants and various additive compounds: an attempt to modify sparingly water soluble drugs to easily water soluble drugs].

It has been established that ionic surfactants, whether cationic or anionic, provide crystalline molecular complexes stably with various aromatic compounds as additives. Among various additives phenolic compounds are especially favorable for both surfactant species. Other than these additives, cationic surfactants easily provide crystalline molecular complexes with basic materials and even with non-polar substances such as biphenyl and phenanthrene. The isolated surfactant molecular complexes were analyzed by X-ray. To date the number of the obtained surfactant molecular complexes exceeds two hundred species or more and thirty or more of them were structurally analyzed. These surfactant molecular complexes were shown to be novel surfactant species different from their mother species, supplied with enhanced solubility to the complex additives. We applied these characteristics to sparingly water soluble drugs as the complex additive to modify them into easily water soluble drugs. The obtained complex drugs revealed an improved behavior in solubility and dissolution rate compared with pure drugs.