Maximizing extraction of botulinum toxin type A from vials

Objectives: To determine the residual botulinum toxin remaining in vials after using 3 different extraction methods and to analyze the different techniques for measuring extraction efficacy. Design: Multicentered comparative study. Setting: Three academic movement disorder clinics. Participants: Thirty physicians were randomly surveyed for their botulinum toxin extraction methods. Three physicians evaluated the most common methods. Interventions: Not applicable. Main Outcome Measure: Amount of toxin left in vials after each extraction method. Results: Toxin was least successfully extracted by using the vial inversion method. More toxin was extracted by using the 2-in needle method. The top removal method produced the least waste of toxin but is considered unsafe. Conclusions: The best and safest method for consistently extracting the most botulinum toxin from its vial was to use a long 21-gauge 2-in needle attached to a 3-mL syringe.