| Autor: |
de M Barbosa R; Biochemistry and Tissue Biology Department, Institute of Biology, University of Campinas, Campinas 13083-862, SP, Brazil. m.g.barbosafernandes@gmail.com.; Pharmacy Department, UNINASSAU-Natal College, Natal 59080-400, RN, Brazil. m.g.barbosafernandes@gmail.com., Ribeiro LNM; Biochemistry and Tissue Biology Department, Institute of Biology, University of Campinas, Campinas 13083-862, SP, Brazil. nuneslica@gmail.com., Casadei BR; Biochemistry and Tissue Biology Department, Institute of Biology, University of Campinas, Campinas 13083-862, SP, Brazil. brucasadei@yahoo.com.br., da Silva CMG; Biochemistry and Tissue Biology Department, Institute of Biology, University of Campinas, Campinas 13083-862, SP, Brazil. camilafarmacia1@yahoo.com.br., Queiróz VA; Biochemistry and Tissue Biology Department, Institute of Biology, University of Campinas, Campinas 13083-862, SP, Brazil. vivianiqueiroz@yahoo.com.br., Duran N; Institute of Chemistry, University of Campinas (UNICAMP), Campinas 13083-861, SP, Brazil. nelsonduran1942@gmail.com., de Araújo DR; Human and Natural Sciences Center, Federal University of ABC, Santo André 09210-580, SP, Brazil. daniele.araujo@ufabc.edu.br., Severino P; Institute of Technology and Research. Av. Murilo Dantas, 300, Aracaju 49032-490, SE, Brazil. pattypharma@gmail.com., de Paula E; Biochemistry and Tissue Biology Department, Institute of Biology, University of Campinas, Campinas 13083-862, SP, Brazil. depaula@unicamp.br. |
| Abstrakt: |
Dibucaine (DBC) is among the more potent long-acting local anesthetics (LA), and it is also one of the most toxic. Over the last decades, solid lipid nanoparticles (SLN) have been developed as promising carriers for drug delivery. In this study, SLN formulations were prepared with the aim of prolonging DBC release and reducing its toxicity. To this end, SLN composed of two different lipid matrices and prepared by two different hot-emulsion techniques (high-pressure procedure and sonication) were compared. The colloidal stability of the SLN formulations was tracked in terms of particle size (nm), polydispersity index (PDI), and zeta potential (mV) for 240 days at 4 °C; the DBC encapsulation efficiency was determined by the ultrafiltration/centrifugation method. The formulations were characterized by differential scanning calorimetry (DSC), electron paramagnetic resonance (EPR), and release kinetic experiments. Finally, the in vitro cytotoxicity against 3T3 fibroblast and HaCaT cells was determined, and the in vivo analgesic action was assessed using the tail flick test in rats. Both of the homogenization procedures were found suitable to produce particles in the 200 nm range, with good shelf stability (240 days) and high DBC encapsulation efficiency (~72⁻89%). DSC results disclosed structural information on the nanoparticles, such as the lower crystallinity of the lipid core vs. the bulk lipid. EPR measurements provided evidence of DBC partitioning in both SLNs. In vitro (cytotoxicity) and in vivo ( tail flick ) experiments revealed that the encapsulation of DBC into nanoparticles reduces its intrinsic cytotoxicity and prolongs the anesthetic effect, respectively. These results show that the SLNs produced are safe and have great potential to extend the applications of dibucaine by enhancing its bioavailability. |
