Preparation of crotaline F-ab antivenom (CroFab®) with automated mixing methods: in vitro observations

Background. Crotaline Polyvalent Ovine Fab antivenom (CroFab®, Savage Laboratories and Protherics Inc., Brentwood, TN, USA) preparation requires that the lyophilized powder be manually reconstituted before use. We compared automated methods for driving the product into solution with the standard manual method of reconstitution, and the effect of repeated rinsing of the product vial, on the per-vial availability of antivenom. Methods. Normal saline (NS, 10 mL) was added to 12 vials of expired CroFab®. Vials were assigned in pairs to each of six mixing methods, including one pair mixed manually as recommended by the product package insert. Each vial's contents were diluted to a final volume of 75 mL of normal saline. Protein concentration was measured with a colorimetric assay. The fluid left in each vial was removed and the vial was washed with 10 mL NS. Results. Total protein yield from each step was calculated. There was no significant change in protein yield among three of five automated mixing methods ...