Patent ID: 8252228

Claim:
A method comprising: introducing a predetermined quantity of biodegradable carriers having a treatment agent disposed therein into a container, wherein the biodegradable carriers comprise nanoparticles or microparticles and are introduced into the container in the form of a solution; lyophilizing the predetermined quantity of biodegradable carriers to form a powder within the container, wherein lyophilizing comprises exposing the biodegradable carriers to a reduced pressure of less than 10 −5 Mpa; after lyophilizing, conditioning the powder of biodegradable carriers to remove moisture, wherein conditioning comprises applying a vacuum to the container followed by introducing an inert gas into the container, wherein the inert gas is one of a nitrogen gas and an argon gas; after conditioning, cooling the powder of biodegradable carriers; and after cooling, sterilizing the container and the conditioned powder of biodegradable carriers, wherein sterilizing comprises exposing the container and the biodegradable carriers to one of a gamma ray or an electron beam.