title: Comparative study of the diffusion of five botulinum toxins type-A in five dosages of use: are there differences amongst the commercially-available products?
abstract: BACKGROUND
  Diffusion halo profiles of different commercially available type-A botulinum toxins (BTX-A) have been studied.
  
  
  OBJECTIVE
  To evaluate and compare the largest diameter of diffusion halos of 5 different doses of 5 different commercially available BTX-A.
  
  
  METHODS
  Twenty-five adult female volunteers were included. Products with 100 units (100 UI) and the product with 500 units (500 UI) were reconstituted in a ratio of 1:2.5. Products were applied in five different concentrations (1 U/2.5 U, 2 U/5 U, 3 U/7.5 U, 4 U/10 U, and 5 U/12.5 U). After 30 days, a starch-iodine test was conducted to obtain the largest diameter of each halo.
  
  
  RESULTS
  For all BTX-As, the higher the number of units used, the larger the diameter of the diffusion halo p<0.05). Statistically significant differences (p<0.05) were observed between the North American and Chinese BTX-As for the three lowest doses, between the Korean and German BTX-As for all doses, between the French and Chinese BTX-As for the four highest doses, between the French and German BTX-As for all doses, between the Chinese and German BTX-As for the four highest doses, and between the North American and German BTX-As for all doses (p<0.01).
  
  
  CONCLUSIONS
  Differences were observed between all brands of BTX-As and between the different doses of each brand.
authors.affiliation: Pontifitial Catholic University of Campinas, Campinas/SP, Brazil.
authors.forename: Adilson
authors.initials: A
authors.lastname: Costa
authors.forename: Elisangela Samartin
authors.initials: ES
authors.lastname: Pegas Pereira
authors.forename: Margareth
authors.initials: M
authors.lastname: de Oliveira Pereira
authors.forename: Felipe Borba
authors.initials: FB
authors.lastname: Calixto dos Santos
authors.forename: Raquel
authors.initials: R
authors.lastname: Favaro
authors.forename: Paula Luz
authors.initials: PL
authors.lastname: Stocco
authors.forename: Lúcia Helena
authors.initials: LH
authors.lastname: Fávaro de Arruda
mesh_terms: D000293:Adolescent; D000328:Adult; D019274:Botulinum Toxins, Type A / Q000008:administration & dosage / Q000493:pharmacokinetics*; D002681:China; D004311:Double-Blind Method; D004345:Drug Industry; D005260:Female; D005602:France; D006801:Humans; D006945:Hyperhidrosis / Q000188:drug therapy; D066298:In Vitro Techniques; D008875:Middle Aged; D009465:Neuromuscular Agents / Q000008:administration & dosage / Q000493:pharmacokinetics*; D009656:North America; D055815:Young Adult
chemical_list: D009465:Neuromuscular Agents; D019274:Botulinum Toxins, Type A