The present invention is drawn to methods of preparing a bioactive agent-containing emulsion for delivery to a biological system. This method can comprise the step of jetting a bioactive agent and a first fluid medium from a fluid-jet pen into a second fluid medium to form a bioactive agent-containing emulsion, wherein the second fluid comprises a continuous phase of the emulsion. Alternatively, a method of preparing a bioactive agent-containing liposome can comprise jetting a lipid-containing composition and a bioactive agent from a fluid-jet pen into a medium to form a bioactive agent-containing liposome carried by the medium. The present invention is also drawn to fluid-jet pens and systems configured for making liposome- and emulsion-containing biological agents.
