NEW ACTIVE PRINCIPLE-CONTAINING MICROPARTICLES, AGENTS CONTAINING THE SAME, THEIR USE FOR THE ULTRASONICALLY CONTROLLED RELEASE OF ACTIVE PRINCIPLES, AND PROCESS FOR PREPARING THE SAME

摘要

New active principle-containing microparticles are disclosed which contain besides the active principle(s) at least one gas or a gaseous phase. Also disclosed are agents containing said particles (microparticulate systems), their use for releasing active principles in vivo in an ultrasonically controlled manner, and processes for preparing the particles and the agents.