| abstract |
The present invention is based, in part, on the unexpected discovery that particles for pulmonary delivery of a therapeutic, prophylactic or diagnostic agent that comprise a phospholipid and a sufficient amount of leucine can produce sustained effect of the agent. Specifically, particles for pulmonary delivery of a therapeutic, prophylactic or diagnostic agent that contain a phospholipid or combination of phospholipids, wherein the phospholipid or combination of phospholipids is present in the particles in an amount of about 1 to 46 weight percent; and leucine, wherein leucine is present in the particles in an amount of at least 46 weight percent, can contribute to sustained effect of the agent. Particles that comprise at least 46 weight percent leucine but that do not contain phospholipids do not exhibit these same sustained effect properties. |