Long-term physicochemical and immunological stability of a liquid formulated intact ovine immunoglobulin-based antivenom

► The stability of liquid antivenom is critical for the safety and efficacy of the product. ► We demonstrate that ovine IgG liquid antivenom remains stable after 42 months at 4 °C and ambient temperature. ► Antivenom remains stable after an additional month stored at 37 °C. ► Correct formulation of liquid antivenom permits long-term stability without requirement for stabilizers or preservatives. ► These results demonstrate retention of antivenom potency in the event of short-term failings in the cold chain.