 NP-018 heptavalent equine-derived botulinum antitoxin is prepared from plasma obtained from horses that have been immunized with a specific subtype of botulinum toxoid and toxin. Each individual horse is immunized against a single botulinum toxin subtype. Plasma is pooled from horses that have been immunized with the same botulinum toxin subtype. For each antitoxin serotype A-G, a despeciated product will be produced by pepsin digestion of the IgG monomer in the equine plasma, yielding predominantly Fab2 fragment. Following the formulation, the seven antitoxin serotypes will be blended into a heptavalent product and filled into single-use vials. 