Formulations comprising anionic agents such as nucleic acids within a lipid-containing particle methods of formulating a lipid-containing particle comprising an anionic agent such as a nucleic acid, methods for preparing a lipid-containing particle comprising an anionic agent such as a nucleic acid, methods for therapeutic delivery of an anionic agent to a patient in need thereof, where the anionic agent is formulated in a lipid-containing particle as described herein.
