Abstract: Particles formed from an alkai metal or alkaline earth metal and halide, for example, sodium and chloride, are provided. The particles can have a hydrophilic coating or external layer, formed of, for example, a polyether-lipid conjugate. In preferred embodiments, the lipid is a phospholipid such as a phosphoethanolamine, and the polyether is a polyethylene glycol such as a PEG amine. Methods making the particles by, for example, a microemulsion reaction, are also provided. Pharmaceutical compositions including a plurality of particles and a pharmaceutically acceptable carrier are also disclosed. Typically the compositions include an effective amount of particles to treat a disease or condition, particularly cancer, in a subject in need thereof. The particles are typically nanoparticles, for example, between about 10 nm and 250 nm and can be monodisperse.