Patent ID: 6623671
Filing Date: 2003-09-23
Classification: A61K,Y10T

Abstract:
A method of producing a population of liposomes substantially free of liposomes above a predetermined maximum size, said method comprising:A. providing a suspension of liposomes, a portion of which are of sizes larger than said predetermined maximum size; and B. extruding liposomes by passing the suspension of liposomes under a pressure of less than about 600 psi about two to ten times through an aluminum oxide porous film, wherein the film is a nontortuous path, branched-pore type anodic aluminum oxide porous film having a pore size of less than about 200 nm, and wherein the filter comprises: (i) an aluminum oxide sheet having two substantially parallel major faces with pores extending from one face of the sheet to the other; and (ii) a first system of larger pores extending from one face into the sheet and a second system of smaller pores extending in from the other face, the system of said larger pores interconnecting with the system of said smaller pores such that the inner ends of one or more smaller pores are joined to the inner end of a larger pore and there are substantially no blind pores; and wherein the liposomes are passed through the aluminum oxide porous film by first entering the film via the smaller pores and extruded via the larger pores.