Patent ID: 9534092
Date: 2017-01-03
CPC Classifications: B07B,C08J,C12N

Claim:
1. A method of preparing hydrogel polymeric particles, the method comprising: filtering a plurality of hydrogel polymeric particles through a first filter having a pore size at a first permeate velocity to provide a first subset of hydrogel polymeric particles in the permeate and having a first particle size distribution; and filtering the first subset of hydrogel polymeric particles through a second filter having the pore size at a second permeate velocity to provide a second subset of hydrogel polymeric particles in the retentate derived from the first subset of hydrogel polymeric particles and having a second particle size distribution narrower than the first particle size distribution; wherein the average particle size of the second subset of hydrogel polymeric particles is in a range of 0.3 micrometers to 1.5 micrometers; wherein the first and second permeate velocities are different.