Use of simple amino acids to form porous particles

Abstract

Particles having a tap density of less than 0.4 g/cm 3 include a hydrophobic amino acid or salt thereof and a therapeutic, prophylactic or diagnostic agent or any combination thereof. Preferred particles include a phospholipid, have a median geometric diameter between about 5 and about 30 microns and an aerodynamic diameter between about 1 and about 5 microns. The particles can be formed by spray-drying and are useful for delivery to the pulmonary system.

1 - 59 . (canceled)  
     
     
         60 . A method of preparing particles having a tap density less than 0.4 g/cm 3  comprising: 
 (a) forming a mixture including a therapeutic, prophylactic or diagnostic agent, or any combination thereof, and an amino acid or a salt thereof; and    (b) spray-drying said mixture to produce particles having a tap density less than about 0.4 g/cm 3 .    
     
     
         61 . The method of  claim 60 , wherein the particles have a median geometric diameter of between about 5 micrometers and about 30 micrometers.  
     
     
         62 . The method of  claim 60 , wherein the particles have an aerodynamic diameter of between about 1 and about 5 microns.  
     
     
         63 . The method of  claim 62 , wherein the particles have an aerodynamic diameter of between about 1 and about 3 microns.  
     
     
         64 . The method of  claim 62 , wherein the particles have an aerodynamic diameter of between about 3 and 5 microns.  
     
     
         65 . The method of  claim 60 , wherein the amino acid is hydrophobic.  
     
     
         66 . The method of  claim 65 , wherein the hydrophobic amino acid is selected form the group consisting of leucine, isoleucine, alanine, valine, phenylalanine and any combination thereof.  
     
     
         67 . The method of  claim 62 , wherein the hydrophobic amino acid is present in the particles in an amount of at least 10% weight.  
     
     
         68 . The method of  claim 60 , wherein the therapeutic, prophylactic or diagnostic agent is present in the particles in an amount ranging from about 1 to about 90% weight.  
     
     
         69 . The method of  claim 60 , wherein the particles further comprise a surfactant.  
     
     
         70 . The method of  claim 60 , wherein the particles further comprise a phospholipid  
     
     
         71 . The method of  claim 70 , wherein the phospholipid is endogenous to the lung.  
     
     
         72 . The method of  claim 70 , wherein the phospholipid is selected from the group consisting of phosphatidylcholines, phosphatidylethanolamines, phosphatidylglycerols, phosphatidylserines, phosphatidylinositols arid combinations thereof.  
     
     
         73 . The method of  claim 60 , wherein the mixture comprises an organic solvent.  
     
     
         74 . The method of  claim 60 , wherein the mixture comprises a co-solvent including an organic solvent and an aqueous solvent.