Patent ID: 7258874

Claim:
A process of preparing controlled release ceramic particles, comprising: (a) providing a reverse micelle solution that is the product of mixing a surfactant with an apolar solvent; (b) providing a precursor solution that is the product of combining a gel precursor, selected from the group consisting of a silica-based gel precursor, an alumina-based gel precursor, a titanium dioxide-based gel precursor, an iron oxide-based gel precursor, a zirconium dioxide-based gel precursor and combinations thereof a catalyst, a condensing agent, and a polar solvent, wherein at least one of the reverse micelle and precursor solutions contains an active material that is soluble in the polar solvent; (c) combining the reverse micelle solution and the precursor solution to generate droplets of the precursor solution in the reverse micelle solution, such that, within the droplets, ceramic particles form that (i) contain the active material and (ii) are porous to the extent of allowing controlled release of the active material; (d) removing solvent and surfactant from the ceramic particles and then (e) drying the ceramic particles, whereby the active material is substantially homogeneously dispersed within each of the particles and throughout the particles.