Flow channel structure for removing foreign substance, method for removing foreign substance, and method for manufacturing lipid particles

A flow channel structure for removing a foreign substance in each of two liquids and mixing the two liquids, comprising:

• partial flow channel structures that remove the foreign substance, each of which has a first flow channel;
• and
• a two-liquid mixing flow channel,
• wherein the first flow channel has a first region having a depth shallower than a depth of another region,
• wherein the two-liquid mixing flow channel has a shape in which a second flow channel and a third flow channel join a fourth flow channel,
• wherein the second flow channel is connected to a downstream of one of the partial flow channel structures,
• wherein the third flow channel is connected to a downstream of an another partial flow channel structure,
• wherein the second flow channel has a second region in which the second flow channel has a depth shallower than a depth of the fourth flow channel at an end of the second flow channel close to the fourth flow channel, and
• wherein the depth of the first region is equal to a depth of the second region.

A method for manufacturing lipid particles encapsulating drugs, comprising:

• flowing each of a first solution containing lipids as a material of the lipid particles in an organic solvent and a second solution containing drugs in an aqueous solvent to the first flow channel of the flow channel structure for removing a foreign substance according to claim 1, and removing a foreign substance in each of the first solution and the second solution;
• mixing the first solution and the second solution after the removing of the foreign substance to obtain a mixed solution;
• and
• granulating the lipids by lowering a concentration of the organic solvent in the mixed solution to form the lipid particles encapsulating the drugs.