[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.

Characterization of coagulase from Staphylococcus intermedius.

A protein coagulase was isolated from Staphylococcus intermedius 6131 using bovine prothrombin-Sepharose 4B and Bio-gel P-4 column chromatographies. Homogeneity was demonstrated by the formation of a single band in polyacrylamide gel electrophoresis and isoelectric focusing. The purified preparation possesses a molecular weight of 64,500, an isoelectric point of 4.1, consists of 615 total amino acid residues and demonstrates coagulase activity for human and rabbit fibrinogen, but does not show the activity for rat or guinea pig fibrinogens. This purified protein contains galactose and fucose, and the amino-terminal amino acid sequence was determined. The coagulase activity is inhibited by N-bromosuccinimide (NBS), suggesting that tryptophan is involved in this activity. The coagulase was heat stable to 80 degrees C and stable to pH over the range of 7-9. This is the first report of coagulase from Staphylococcus intermedius.

Light and Oxygen Protective Properties of Materials Induced by Surfactant Molecular Complex Formation.

Crystalline surfactant molecular complexes, the quite stable existence of which we firmly established through X-ray structural analysis, etc., were examined with respect to the protection from UV light and oxygen provided to their additive components. Structural analysis has revealed that the complex additives are stably occluded in the mother surfactant crystal matrix. Through the examination it was confirmed that additive components in a cationic complex crystal structure were perfectly protected from both UV light and oxygen. On the other hand, in anionics the additives were perfectly safe from UV attack, but from oxygen the change was rather accelerated in comparison with the effect of that on the pure condition. Copyright 2000 Academic Press.

Solution Behavior of Anionic Surfactant Molecular Complexes

We have already reported the solution behavior as examined by electrical conductivity for cationic surfactant molecular complexes composed of quaternary ammonium salts such as CTAB and various aromatic additive species such as phenols and amines. By the same electrical conductivity method, we have obtained many valuable results which establish the newly obtained anionic surfactant molecular complexes to be novel surfactant species displaying their own characteristic CMCs and Krafft points different from those of their mother surfactants. Through the solution behavior, furthermore, we could deduce that a solubilized solution system that was of molar composition equal to that of the complex in the surfactant and the solubilizate (additive) was perfectly identical to the dissolution system of the complex. The facts satisfactorily confirmed that a solubilized solution system was only the dissolution system of the complex which spontaneously resulted in the process of solubilization.