Liposomes were prepared by controlled mixing of the lipidic solution and aqueous solution using a V-junction device which was equipped with 2 inlet tubes for the feed solution and one outlet tube collecting the liposomal formulation. The inlet tubes were equipped with one-way valves and connected to a syringe pump controlling the flow rate (Figure ). DPPC and DSPC (8:2 molar ratio) were prepared in ethanol at 5 mg/mL, to which 5% (w/w to lipids) DSPE-PEG was added. The liposomes were prepared by mixing of the ethanol-lipid solution with an aqueous teriparatide solution (0.25 mg/mL) in 20 mM phosphate buffer (pH 7.2) at a flow rate of 450 mL/h using a water: ethanol ratio of 4:1 v/v. The resulting liposomes were purified by gel filtration (see Section 2.4.1).