Multicenter, double-blind study of the efficacy of injections with botulinum toxin type A reconstituted up to six consecutive weeks before application.
BACKGROUND
It is recommended that botulinum toxin be used immediately or within 2 weeks after its reconstitution because its efficacy might be compromised by prolonged storage.


OBJECTIVE
To evaluate the efficacy of botulinum toxin type A (BTX-A) reconstituted over 6 consecutive weeks for the treatment of glabellar frown lines.


METHODS
Four vials of BTX-A were reconstituted each of 7 days over a period of 6 weeks, totaling 28 vials, corresponding to seven reconstitution dates. During this period, the BTX-A was stored according to the manufacturer's instructions. On the day after the last reconstitution, all of the reconstituted vials were injected in patients from four dermatologic centers taking part in this study. A total of 88 patients were treated on the same day and were followed every 2 weeks for 4 months. All patients were photographed at all stages. A number of professionals assessed the efficacy of reconstituted BTX-A based on the reduction of the maximum frowning capacity of the treated muscles.


RESULTS
Of the 88 patients who were selected, 3 were excluded. Three forms of evaluation were applied, and no statistically significant differences were found in the results presented.


CONCLUSIONS
BTX-A may be applied up to 6 weeks after reconstitution without losing its effectiveness. Other factors, which are probably individual, may influence the response to BTX-A injections.
Hexsel
Doris Maria
DM
dohexsel@zaz.com.br
De Almeida
Ada Trindade
AT
Rutowitsch
Marcio
M
De Castro
Inês Alencar
IA
Silveira
Vera Lúcia Bauer
VL
Gobatto
Daniela Orso
DO
Zechmeister
Mônica
M
Mazzuco
Rosemari
R
Zechmeister
Dêbora
D
D000328:Adult; D000368:Aged; D019274:Botulinum Toxins, Type A / Q000494:pharmacology*; D004311:Double-Blind Method; D004339:Drug Compounding / Q000379:methods; D004355:Drug Stability; D004356:Drug Storage / Q000379:methods*; D005260:Female; D005546:Forehead; D006801:Humans; D007267:Injections; D008297:Male; D008875:Middle Aged; D015595:Skin Aging / Q000187:drug effects*; D013997:Time Factors; D016896:Treatment Outcome
D019274:Botulinum Toxins, Type A