Particulate poly(lactic-co-glycolic) acid, method for manufacturing particulate poly(lactic-co-glycolic) acid, and particulate poly(lactic-co-glycolic) acid manufacturing apparatus

Abstract

A particulate poly(lactic-co-glycolic) acid (PLGA) is provided. The particulate PLGA comprises a poly(lactic-co-glycolic) acid (PLGA), and has an average volume-based particle diameter of 80 nm or less and a relative span factor (R.S.F.) satisfying the following formula (1): 0<R.S.F.≦1.20  Formula (1) where R.S.F. is defined by (D90−D10)/D50, where D90, D50, and D10 respectively represent particle diameters at cumulative rates of 90%, 50%, and 10% by volume based on a cumulative particle size distribution counted from a small-particle side.

1 . A particulate poly(lactic-co-glycolic) acid (PLGA) comprising:
 a poly(lactic-co-glycolic) acid (PLGA),   wherein the particulate PLGA has an average volume-based particle diameter of 80 nm or less and a relative span factor (R.S.F.) satisfying the following formula (1):
   0<R.S.F.≦1.20  Formula (1)
 
   
       where R.S.F. is defined by (D90−D10)/D50, where D90, D50, and D10 respectively represent particle diameters at cumulative rates of 90%, 50%, and 10% by volume based on a cumulative particle size distribution counted from a small-particle side. 
     
     
         2 . The particulate PLGA of  claim 1 , wherein the average volume-based particle diameter is in the range of from 10 to 50 nm. 
     
     
         3 . The particulate PLGA of  claim 1 , further comprising a physiologically active substance. 
     
     
         4 . A method for manufacturing particulate poly(lactic-co-glycolic) acid (PLGA), comprising:
 dissolving a poly(lactic-co-glycolic) acid (PLGA) in a good solvent of the PLGA to obtain a PLGA solution; and   discharging the PLGA solution from at least one discharge hole having an inner diameter of less than 1.0 mm into a poor solvent of the PLGA.   
     
     
         5 . The method of  claim 4 , wherein the discharging includes applying a vibration to the PLGA solution. 
     
     
         6 . The method of  claim 4 , wherein the discharging includes letting the poor solvent to flow. 
     
     
         7 . The method of  claim 6 , wherein the poor solvent has at a flow rate of 0.3 m/s or more. 
     
     
         8 . The method of  claim 4 , wherein the discharging includes circulating the poor solvent. 
     
     
         9 . The method of  claim 8 , further comprising removing the good solvent from within the circulated poor solvent. 
     
     
         10 . A particulate poly(lactic-co-glycolic) acid (PLGA) manufacturing apparatus, comprising:
 a PLGA solution storage storing a PLGA solution in which a poly(lactic-co-glycolic) acid (PLGA) is dissolved in a good solvent of the PLGA;   a solution discharger having at least one discharge hole having an inner diameter of less than 1.0 mm, connected to the PLGA solution storage; and   a poor solvent storage storing a poor solvent of the PLGA.   
     
     
         11 . The PLGA manufacturing apparatus of  claim 10 , wherein the solution discharger includes a vibration applicator configured to apply a vibration to the PLGA solution. 
     
     
         12 . The PLGA manufacturing apparatus of  claim 10 , further comprising a liquid flow unit configured to let the poor solvent to flow. 
     
     
         13 . The PLGA manufacturing apparatus of  claim 10 , wherein the poor solvent storage includes a circulation channel configured to circulate the poor solvent. 
     
     
         14 . The PLGA manufacturing apparatus of  claim 13 , further comprising a good solvent remover configured to remove the good solvent from within the circulated poor solvent.