title: Efficacy of liposome-encapsulated mepivacaine for infiltrative anesthesia in volunteers.
abstract: This blinded crossover study evaluated the efficacy and pain sensitivity evoked by a previously reported liposome-encapsulated mepivacaine formulation (Araujo et al., 2004). Thirty healthy volunteers received an intraoral injection (1.8 mL), at four different sessions, of the following formulations: 2% mepivacaine with 1:100,000 epinephrine (MVC(2%EPI)), 3% mepivacaine (MVC(3%)), and 2 and 3% liposome-encapsulated mepivacaine (MVC(2%LUV) and MVC(3%LUV)). Latency period and duration of anesthesia were assessed by an electrical pulp tester and injection discomfort by a visual analog scale (VAS). Data were analyzed with Tukey-Kramer and Friedman tests (P < 0.05). No significant difference was found regarding latency period (in minutes) among the formulations (P > 0.05). The duration of anesthesia after the injection of MVC(3%LUV) was higher than the one obtained after the infiltration of MVC(2%LUV) and of MVC(3%) (P < 0.05). However, the duration of anesthesia obtained with MVC(3%) did not differ from the one obtained with MVC(2%LUV) (P > 0.05). MVC(3%LUV) showed lower VAS median values than MVC(2%EPI) (P < 0.05), and there were no significant differences among the others formulations. Liposome-encapsulated 3% mepivacaine showed longer duration of anesthesia, in comparison to the commercial formulation of MVC(3%). MVC(2%LUV) was able to produce a similar duration of anesthesia as the 3% commercial formulation, despite the 50% decrease in the anesthetic concentration. Thus, the encapsulation of mepivacaine increased the duration of anesthesia and reduced the injection discomfort caused by vasoconstrictor-associated formulations in healthy volunteers.
authors.affiliation: UNIFAG (Clinical Pharmacology and Gastroenterology Unit), São Francisco University, Bragança Paulista, São Paulo, Brazil.
authors.forename: Giovana R
authors.initials: GR
authors.lastname: Tofoli
authors.forename: Cíntia M S
authors.initials: CM
authors.lastname: Cereda
authors.forename: Francisco C
authors.initials: FC
authors.lastname: Groppo
authors.forename: Maria C
authors.initials: MC
authors.lastname: Volpato
authors.forename: Michelle
authors.initials: M
authors.lastname: Franz-Montan
authors.forename: José
authors.initials: J
authors.lastname: Ranali
authors.forename: Daniele Ribeiro
authors.initials: DR
authors.lastname: de Araújo
authors.forename: Eneida
authors.initials: E
authors.lastname: de Paula
mesh_terms: D000328:Adult; D000779:Anesthetics, Local / Q000008:administration & dosage / Q000627:therapeutic use*; D018592:Cross-Over Studies; D004311:Double-Blind Method; D004837:Epinephrine / Q000008:administration & dosage; D005260:Female; D006801:Humans; D008081:Liposomes; D008297:Male; D008619:Mepivacaine / Q000008:administration & dosage / Q000627:therapeutic use*; D008875:Middle Aged
chemical_list: D000779:Anesthetics, Local; D008081:Liposomes; D008619:Mepivacaine; D004837:Epinephrine