Microspheres and method for producing them

Abstract

An organic solvent-free method for producing a plurality of microsphere having an average diameter of less than 500 μm in diameter and having average contact angle θc greater than 140°, consisting essentially of a biocompatible hot-melt carrier vehicle and a payload substance to be delivered, comprising; melting and mixing a polymer carrier vehicle which is solid at room temperature and at least one payload substance, and dispensing microportions of the molten mixture through a droplet-forming space onto a cooled solid superoleophobic surface.

1 .- 20 . (canceled) 
     
     
         21 . A plurality of microspheres:
 wherein said plurality of microspheres have an average diameter of less than 500 μm and an average contact angle θ c  greater than 140°;   each microsphere within the plurality of microspheres comprises a mixture of:   (i) carrier vehicle having a melting point of about 45° C. to 200° C.; and   (ii) a payload substance that is solid or liquid in room temperature and has a melting point suitable to be dissolved or dispersed in a molten mixture and is thermally stable in a molten mixture.   
     
     
         22 . The plurality of microspheres of  claim 21 , wherein said carrier vehicle comprises one or more carrier selected from the group consisting of polyolefins C 20  and higher, polyamides, polyvinyls, polyesters, polyurethanes, polycarbonates, polyacrylates, fatty acids, fatty alcohols, aliphatic alkyl amines, lipids and waxes. 
     
     
         23 . The plurality of microspheres of  claim 22 , wherein said carrier vehicle is a polymeric carrier vehicle. 
     
     
         24 . The plurality of microspheres of  claim 22 , wherein said carrier vehicle comprise one or more member selected from the group consisting of polylactic acid (PLA), Poly(lactic-co-glycolic acid) (PLGA), polycaprolactone (PCL), cetyl alcohol, oxidized polyethylene (PE), and waxes. 
     
     
         25 . The plurality of microspheres of  claim 24 , wherein said polymeric carrier vehicle comprises polylactic acid (PLA), polyglycolic acid (PGA), and their copolymers (PLGA). 
     
     
         26 . The plurality of microspheres of  claim 25 , wherein said polymeric carrier vehicle comprises poly(lactic-co-glycolic acid) (PLGA). 
     
     
         27 . The plurality of microspheres of  claim 24 , wherein said polymeric carrier vehicle comprises polycaprolactone (PCL). 
     
     
         28 . The plurality of microspheres of  claim 22 , wherein said carrier vehicle comprises paraffin wax. 
     
     
         29 . The plurality of microspheres of  claim 23 , wherein said polymeric carrier vehicle comprises oxidized polyethylene. 
     
     
         30 . The plurality of microspheres of  claim 22 , wherein said carrier vehicle comprises cetyl alcohol. 
     
     
         31 . The plurality of microspheres of  claim 21 , wherein said payload substance comprises essential oil. 
     
     
         32 . The plurality of microspheres of  claim 21 , wherein said payload substance comprises an active pharmaceutical ingredient. 
     
     
         33 . The plurality of microspheres of  claim 21 , having an average contact angle θ c  greater than 150°. 
     
     
         34 . The plurality of microspheres of  claim 21 , wherein at least 75% of the plurality of microspheres having a uniform spherical surface. 
     
     
         35 . The plurality of microspheres of  claim 21 , wherein at least 85% of the plurality of microspheres having a uniform spherical surface. 
     
     
         36 . The plurality of microspheres of  claim 21 , wherein at least 95% of the plurality of microspheres having a uniform spherical surface.