Anesthetic eficacy of bupivacaine complexed with 2-hydroxypropyl-ß-cyclodextrin in alveolar inferior nerve block and subcutaneous infiltration in surgical wound, in rats

Author(s)

Luciano Serpe

• Document type: Master's Dissertation
• Press: Piracicaba, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Faculdade de Odontologia de Piracicaba
• Defense date: 2012-02-27

Examining board members

Francisco Carlos Groppo; Paulo Henrique Ferreira Caria; Rogério Heládio Lopes Motta

• Advisor: Maria Cristina Volpato; Francisco Carlos Groppo

Abstract

The aim of the present study was to evaluate the anesthetic efficacy of 2-hydroxypropyl ß-cyclodextrin bupivacaine formulation, compared with commercial bupivacaine solutions, in two experimental models: inferior alveolar nerve block (IANB) and subcutaneous infiltration in surgical wound (SISW). For IANB, 30 rats received an injection of 0.2mL of one of the following formulations, near to the mandibular foramen: 0.5% bupivacaine (Bupi), 0.5% bupivacaine with 1:200.000 epinephrine (Bupi-Epi), and 0.5% bupivacaine in 2-hydroxypropyl-ß-cyclodextrin inclusion complex (Bupi-HPßCD). The contralateral sides (control) received 0.9% NaCl or anesthetic free 2-hydroxypropyl-ß-cyclodextrin (HPß CD) solution. The onset, success and duration of pulpal anesthesia were assessed by electrical stimulation ("pulp tester"). For SISW, 30 animals received 0.1 mL of each anesthetic formulation (both hind paws) or their respective control, 24 hours after hypernociception induction (surgical wound - incision and suture) in the right hind paw. The left hind paw also received the injection and was the control without hypernociception. Analgesia was evaluated by applying force lateral to the incision (von Frey aesthesiometer). Results were submitted to ANOVA and Tukey, Student-Newman-Keuls, Kruskal-Wallis, Log Rank and Chi-square tests (alfa = 5%). No differences were observed among the formulations concerning IANB onset (p>0.05); Bupi presented lower anesthesia duration (p<0.05) than Bupi-Epi and Bupi-HPßCD, with no difference between these two solutions (p>0.05). Bupi-Epi presented higher anesthesia success than Bupi-HP?CD, which showed higher success than Bupi (p<0.05). For SISW, Bupi-Epi showed higher anesthesia success than Bupi (p<0.05) in the non hypernociceptive paws; Bupi-HPßCD did not differ from the others (p>0.05). In this condition Bupi-Epi provided higher anesthesia success than the other formulations and Bupi-HPßCD presented higher anesthesia success than Bupi (p<0.05). In the hypernociceptive paws, Bupi-Epi promoted higher anesthesia success than the other formulations (p<0.05), with no difference between Bupi-HPß CD and Bupi (p<0.05). No difference among formulations were observed in relation to anesthesia duration in the hypernociceptive paws (p>0.05). In conclusion, the complexation of bupivacaine in HPßCD increased anesthesia success, but not duration in IANB and SISW without hypernociception in relation to bupivacaine; in the presence of hypernociception it did not improved bupivacaine efficacy. Epinephrine increased bupivacaine efficacy, except in SISW model with hypernociception, which decreased efficacy of all bupivacaine solutions studied (AU)

• FAPESP's process: 09/11820-3 - The anesthetic eficacy of hydroxypropyl-beta-cyclodextrin bupivacaine formulations in alveolar inferior nerve block and wound healing in rats.
• Grantee: Luciano Serpe
• Support Opportunities: Scholarships in Brazil - Master