Incorrect reconstitution of incobotulinumtoxinA leads to loss of neurotoxin.

Background: IncobotulinumtoxinA (INCO) was approved for aesthetic use in the United States in 2011. When reconstituted per manufacturer's instructions, diminished delivery of INCO in US may result. Objective: Investigators sought to determine whether potential loss of decreased motor activity could be demonstrated, using a simple reconstitution technique. Methods and Materials: In this 5-patient study, investigators added 2.0 mL of saline to INCO powder at the bottom of the first of 5 vials, swirling gently to dissolve INCO powder at the bottom. Reconstituted INCO was discarded and the cap was replaced. The "empty" vial then received 0.6 mL of saline, and was swirled and inverted 3 times to ensure dissolution. The 0.6 mL from the first vial was added to the second "empty" vial and the process was repeated for the remaining 3 vials (5 vials per patient). Patients were injected from reconstitution of "empty" vials to determine neuromodulatory activity. Pre- and post-treatment patient photographs of maximal contraction were taken. Results: Markedly diminished maximal frown could be observed in all 5 patients. Conclusion: Improper reconstitution of INCO, or swirling without inversion of the vial following saline injection, can result in significant loss of units of the neurotoxin in the clinical setting.