title: Foam during reconstitution does not affect the potency of botulinum toxin type A.
abstract: BACKGROUND
  Among factors that may affect the potency of botulinum toxin A (Botox), it is said that foam, together with bubbles, may cause surface denaturation of the toxin.
  
  
  OBJECTIVE
  To determine whether the muscle relaxation effect of Botox is preserved and has the same duration when it is reconstituted in the presence of foam.
  
  
  METHODS
  Six female volunteers, aged 42 to 56 years old, were treated for glabellar and periocular wrinkles. Each half of the face was treated with 16 U of Botox divided in four sites: three at the lateral orbital area and one at the medial brow, in the glabellar region. The right side received Botox gently reconstituted with saline to avoid foaming formation. The left side of the face was treated with Botox that was rapidly reconstituted in order to achieve as many bubbles as possible, even with shaking. Blinded observers compared pretreatment and posttreatment photographs and answered assessment-related questions. The results were analyzed clinically and statistically.
  
  
  RESULTS
  There was no difference in muscle paralysis between treated sides in all patients, neither in early (15 days) nor late (4 months) follow-up evaluations.
  
  
  CONCLUSIONS
  Botox maintains its potency even in the presence of foaming during the reconstitution process.
authors.affiliation: Dermatologic Clinic of Hospital do Servidor Público Municipal de São Paulo, São Paulo, Brazil. artrindal@uol.com.br
authors.forename: Ada Regina
authors.initials: AR
authors.lastname: Trindade De Almeida
authors.forename: Bogdana Victoria
authors.initials: BV
authors.lastname: Kadunc
authors.forename: Nilton
authors.initials: N
authors.lastname: Di Chiacchio
authors.forename: Dalva Regina
authors.initials: DR
authors.lastname: Neto
mesh_terms: D000328:Adult; D019274:Botulinum Toxins, Type A / Q000494:pharmacology*; D004339:Drug Compounding / Q000379:methods; D004355:Drug Stability; D005260:Female; D006801:Humans; D008875:Middle Aged; D009465:Neuromuscular Agents / Q000494:pharmacology*
chemical_list: D009465:Neuromuscular Agents; D019274:Botulinum Toxins, Type A