Abstract
Dibucaine (DBC) belongs to the amino amide family of local anesthetics. Unlike other anesthetic compounds it possesses a rigid, butyl substituted, quinolinic ring that imposes restrictions to its interaction with membranes. Solid Lipid Nanoparticles (SLN) has been attracting attention as a promising drug delivery system because it combines advantages such as versatility, use of safe excipients, a wide potential for the controlled drug release of drugs and good shelf stability. The aim of this study was to develop SLN prepared with cetylpalmitate (CP) as the lipid matrix and poloxamer 188 as a colloidal stabilizer to encapsulate DBC. Nanoparticles were prepared with the high pressure hot homogenization method and characterized by transmission electron microscopy (TEM), small-angle X-ray scattering (SAXS) and electron paramagnetic resonance (EPR). The association constant or partition coefficient was measured (177.02 ± 6.31). TEM images disclosure structures with delineated spherical surfaces and homogenous size distribution (ca. 250-300 nm), in good agreement with photon correlation spectroscopy data; incorporation of DBC did not change the morphology and size of the nanoparticles. SAXS data showed that the lipids in the SLN are organized in a liquid crystal-like structure, with small amounts of water inside it (the same results were observed in the SLN loaded with DBC). EPR spectra of 5-nitroxyl stearic acid incorporated into SLN were compatible with SAXL data and revealed that dibucaine insertion into the nanoparticles changed the lipid packing sensed by the spin label, decreasing its isotropic signal. In conclusion we have shown that DBC can be successfully incorporated into SLN, changing its lipid packing without destabilizing the overall nanoparticle structure, indicating that this is a promising drug delivery system. Supported by FAPESP (# 06/00121-9), CAPES, CNPq.
Published Version (Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have