Stabilized capillary microjet and devices and methods for producing same

A method of manufacturing coated particles, comprising the steps of:

• (a) forcing a liquid formulation comprising a pharmaceutically active drug through a channel of a first feeding source in a manner which causes a stream of the liquid drug to be expelled from a first exit opening at a first velocity;
• (b) forcing a liquid comprising a coating material through a second channel concentrically positioned around the first channel in a manner which causes a stream of the liquid coating material to be expelled from a second exit opening at a velocity which is substantially the same as the first velocity whereby the stream of coating material is concentrically positioned around the stream of liquid drug;
• (c) forcing a gas through a pressure chamber in a manner which causes the gas to exit the pressure chamber from an exit orifice positioned downstream of the concentrically positioned streams of liquid drug and coating material;
• wherein the density of the liquid formulation comprising the pharmaceutically active drug is substantially the same as the density of the liquid comprising the coating material, and the gas focuses the concentrically positioned streams to a stable unified jet which flows out of the chamber exit orifice and breaks up into a first group of coated particles of the pharmaceutically active drug coated with the coating material;
• and
• (d) repeating the steps (a)-(c) in a manner such that the coating on a second group of coated particles has a different thickness from the coating of the first group of coated particles.