摘要：

A suspension of liposomes, preferably formulated to contain an entrapped drug, whose sizes are predominantly greater than about 1 micron is passed through an asymmetric ceramic filter whose inner-surface pore size is about 1 micron. The extrusion system (24) used employs a cartridge-type filter apparatus (8) and includes a pump (26) and a pair of vessels (28, 30) which hold the liposome suspensions to be processed. The pump is connceted to the vessels through a series of valves such as valve (32), for effecting fluid flow either in a forward direction from vessel (28), through the apparatus in an inside-to-outside direction, or in the reverse, back direction. From vessel (30), the processed liposome suspension can be transferred to a sterile fill system. The processed liposomes have a selected average size of about 0.4 microns or less, depending on the number of filter cycles, and a narrow distribution.

展开