Spherical microparticles containing linear polysaccharides

Abstract

Microparticles with a uniform spherical shape and a very narrow size distribution are described. They consist wholly or partly of a linear water-insoluble polysaccharide, preferably of 1,4-α-D-polyglucan, and may contain other, in particular biodegradable, polymers and/or active substances. They are suitable inter alia for the controlled delivery of active substances. They are prepared by dissolving 1,4-α-D-polyglucan or the polysaccharide in a solvent, introducing the solution into a precipitant, cooling the mixture and removing the particles formed.

1 . Spherical microparticles having an average diameter of 1 nm to 100 μm, consisting wholly or partly of at least one water-insoluble linear polysaccharide.  
     
     
         2 . Spherical microparticles having an average diameter of 1 nm to 100 μm, consisting wholly or partly of at least one water-insoluble linear polysaccharide which has been prepared in a biotechnological process.  
     
     
         3 . Spherical microparticles having an average diameter of 1 nm to 100 μm as claimed in  claim 2 , consisting wholly or partly of at least one water-insoluble linear polysaccharide which has been prepared by a biocatalytic process.  
     
     
         4 . Spherical microparticles having an average diameter of 1 nm to 100 μm as claimed in  claim 2 , consisting wholly or partly of at least one water-insoluble linear polysaccharide which has been prepared by a fermentation process.  
     
     
         5 . Spherical microparticles as claimed in  claim 1 , consisting wholly or partly of 1,4-α-D-polyglucan.  
     
     
         6 . Microparticles as claimed in  claim 5 , wherein 1,4-α-D-polyglucan has been prepared by a biocatalytic process using polysaccharide synthases.  
     
     
         7 . Microparticles as claimed in,  claim 5 , wherein 1,4-α-D-polyglucan has been prepared by a biocatalytic process using starch synthases.  
     
     
         8 . Microparticles as claimed in  claim 5 , wherein 1,4-α-D-polyglucan has been prepared by a biocatalytic process using glycosyl-transferases.  
     
     
         9 . Microparticles as claimed in  claim 5 , wherein 1,4-α-D-polyglucan has been prepared by a biocatalytic process using α-1,4-glucan transferases.  
     
     
         10 . Microparticles as claimed in  claim 5 , wherein 1,4-α-D-polyglucan has been prepared by a biocatalytic process using glycogen synthases.  
     
     
         11 . Microparticles as claimed in  claim 5 , wherein 1,4-α-D-polyglucan has been prepared by a biocatalytic process using amylosucrases.  
     
     
         12 . Microparticles as claimed in  claim 5 , wherein 1,4-α-D-polyglucan has been prepared by a biocatalytic process using phosphorylases.  
     
     
         13 . Microparticles as claimed in  claim 1 , wherein the linear polysaccharides have been prepared by enzymatic treatment of branched or highly branched polysaccharides.  
     
     
         14 . Microparticles as claimed in at least one of  claims 1  to  13  having an average diameter of 100 nm to 10 μm, preferably 1 to 3 μm.  
     
     
         15 . Microparticles as claimed in at least one of  claims 1  to  14 , having a narrow distribution of particle diameters (dispersity).  
     
     
         16 . Microparticles as claimed in  claim 15 , wherein the dispersity of the particle diameters d w  to d n  is 1.0 to 10.0, preferably 1.5 to 5.0, in particular 2.0 to 2.6.  
     
     
         17 . Microparticles as claimed in at least one of  claims 1  to  16 , which additionally comprise one or more, preferably biodegradable polymers.  
     
     
         18 . Microparticles as claimed in one or more of  claims 1  to  17 , which additionally comprise one or more active substances.  
     
     
         19 . A process for preparing spherical microparticles which consist wholly or partly of water-insoluble linear polysaccarides, in particular 1,4-α-D-polyglucan, by dissolving the water-insoluble linear polysaccharide or the 1,4-α-D-polyglucan in a solvent, introducing the solution into a precipitant, cooling the mixture resulting therefrom, and removing the microparticles formed.  
     
     
         20 . The process as claimed in  claim 19 , wherein solution and precipitant are mixed at temperatures from 20 to 50° C., and the mixture is cooled to temperatures from +10 to −10° C., preferably 5 to −5° C.  
     
     
         21 . The process as claimed in  claim 19  or  20 , wherein dimethyl sulfoxide is used as solvent.  
     
     
         22 . The process as claimed in at least one of  claims 19  to  21 , wherein water or an aqueous medium is used as precipitant.  
     
     
         23 . The process as claimed in at least one of  claims 19  to  22 , wherein the solution is prepared in the presence of one or more polymers, in particular biodegradable polymers, and/or of one or more active substances.  
     
     
         24 . The use of the microparticles as claimed in at least one of  claims 1  to  18  or of the microparticles prepared by a process as claimed in at least one of  claims 19  to  23  for the controlled delivery of active substances.  
     
     
         25 . The use of the microparticles as claimed in at least one of  claims 1  to  18  or of the microparticles, prepared by a process as claimed in at least one of  claims 19  to  23  as standard for determining the size of particles.