title: Reconstituted botulinum type A neurotoxin: clinical efficacy after long-term freezing before use.
abstract: Botulinum neurotoxin type A (BoNT/A) is injected into muscles of facial expression for treatment of facial wrinkles. Manufacturers' recommendations state that the product should be used within 4 h of reconstitution to prevent loss of effectiveness. A prospective study was undertaken to evaluate the effectiveness of reconstituted BoNT/A when preserved in a frozen state for up to 6 months, as compared with nonfrozen BoNT/A used within 4 h after reconstitution. Treatment of 118 sites in 80 patients was performed and evaluated for aesthetic efficacy. Excellent results were observed in 94.8% of sites treated with nonfrozen BoNT/A and in 93.3% of the sites treated with frozen and thawed BoNT/A (p = 1). Minor side effects were rare and transient in both groups. In contrast to common belief, reconstituted BoNT/A may be frozen, thawed, and injected without losing its potency for up to 6 months, with efficacy equivalent to that of freshly prepared BoNT/A.
authors.affiliation: Department of Internal Medicine, Seton Hall University School of Graduate Medical Education, St. Francis Medical Center, Trenton, NJ, USA.
authors.forename: Alan A
authors.initials: AA
authors.lastname: Parsa
authors.forename: Kevin D
authors.initials: KD
authors.lastname: Lye
authors.forename: Fereydoun Don
authors.initials: FD
authors.lastname: Parsa
mesh_terms: D000328:Adult; D000368:Aged; D019274:Botulinum Toxins, Type A / Q000008:administration & dosage* / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D004341:Drug Evaluation; D004349:Drug Packaging / Q000379:methods; D004356:Drug Storage / Q000379:methods*; D005260:Female; D005612:Freeze Drying; D006801:Humans; D008297:Male; D008875:Middle Aged; D009465:Neuromuscular Agents / Q000008:administration & dosage* / Q000378:metabolism*; D011446:Prospective Studies; D015361:Rhytidoplasty / Q000379:methods*; D016896:Treatment Outcome
chemical_list: D009465:Neuromuscular Agents; D019274:Botulinum Toxins, Type A