Agent-encapsulating micro- and nanoparticles, methods for preparation of same and products containing same

A method of preparing substantially leachless, agent-encapsulating sol gel particles, the method comprising:

• emulsifying an inner phase containing at least one agent and at least one first sol-gel precursor in an outer phase containing a dispersing medium and producing initial sol-gel particles encapsulating said at least one agent;
• and
• reacting said initial sol-gel particles with at least one second sol-gel precursor, thereby obtaining said substantially leachless, agent-encapsulating sol-gel particles;
• wherein said substantially leachless agent-encapsulating sol-gel particles are characterized by leaching of no more than 2 weight percentages of said at least one agent from therein upon mixing and agitating said sol gel particles with an extraction medium for at least 7 days at 40° C.