The present invention relates to a novel pH triggered, targeted controlled release system. The controlled delivery system of the present invention is substantially a free-flowing powder formed of solid hydrophobic nano-spheres comprising pharmaceutical active ingredients that are encapsulated in a pH sensitive micro-spheres. The invention also relates to the processes for preparing the compositions and processes for using same. The controlled release system can be used to target and control the release of pharmaceutical active ingredients onto certain regions of the gastrointestinal tract including the stomach and the small intestine. The invention further pertains to pharmaceutical products comprising the controlled release system of the present invention.