Small particles of a heparin/chitosan complex prepared from a pharmaceutically acceptable microemulsion

A water-in-oil microemulsion based on ingredients acceptable for oral administration of substances to human was investigated. The microemulsion was studied with and without biologically active ingredients by dynamic light scattering, turbidity, diffusion-NMR, and conductivity. Also, a technology based on mixing of appropriate microemulsions was investigated as a means to produce particles of nanometer size of a heparin/chitosan complex. It was found that the microemulsion existed up to about 15% (w/w) of water with or without active ingredients. Formation of nanosized heparin/chitosan particles inside the water droplets was confirmed. It was concluded that the investigated microemulsion could be an interesting system for the oral administration of a heparin/chitosan complex. (C) 2003 Elsevier Science B.V. All rights reserved.