pH triggered release particle

Controlled release particles, each controlled release particle of which comprises:

• a core comprising at least one hydrophobic active material and an emulsifier which is an oil-soluble or oil-dispersible lecithin emulsifier;
• and
• a wall at least partially surrounding the core and comprising:
• an acid insoluble polymer;
• a colloidal silica;
• a water insoluble divalent salt;
• a film forming polymer;
• and optionally
• a powder flow aid,
• wherein:
• (a) the controlled release particle is configured to retain the at least one hydrophobic active material when exposed to an acidic aqueous solution with a pH less than 6, and to release the at least one hydrophobic active material when exposed to a basic aqueous solution with a pH greater than 7, (b) the acid insoluble polymer and the film forming polymer are water soluble, and (c) the formation of the wall does not require the use of organic solvents in the core or wall.