The invention refers to process for preparing a bio-resorbable polyester in particulate form, comprising the steps: a) providing a bio-resorbable polyester with in the form of a dry polymer mass or in the form of a wet polymer mass； b) feeding the polymer mass from step a) into an extruder extruder with at least one degassing zone where the polymer mass is molten, extruded and degassed； c) discharging the degassed polymer mass out of the extruder； d) comminuting the discharged polymer mass to particles with —a bulk density of 0.3 g/ml or more, —a tapped density of 0.4 g/ml or more and —a specific surface area of 2.0 m2/g or less.
