Liquid drugs are stored in vials, IV bags, ampoules, cartridges, and prefilled syringes.
As with solid formulations, liquid formulations combine the drug product with a variety of compounds to ensure a stable active medication following storage. These include solubilizers, stabilizers, buffers, tonicity modifiers, bulking agents, viscosity enhancers/reducers, surfactants, chelating agents, and adjuvants.
If concentrated by evaporation, the drug may be diluted before administration. For IV administration, the drug may be transferred from a vial to an IV bag and mixed with other materials.