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A pre-formulation study of tetracaine loaded in optimized nanostructured lipid carriers.

ABSTRACT: Tetracaine (TTC) is a local anesthetic broadly used for topical and spinal blockade, despite its systemic toxicity. Encapsulation in nanostructured lipid carriers (NLC) may prolong TTC delivery at the site of injection, reducing such toxicity. This work reports the development of NLC loading 4% TTC. Structural properties and encapsulation efficiency (%EE > 63%) guided the selection of three pre-formulations of different lipid composition, through a 2³ factorial design of experiments (DOE). DLS and TEM analyses revealed average sizes (193-220 nm), polydispersity (< 0.2), zeta potential |- 21.8 to - 30.1 mV| and spherical shape of the nanoparticles, while FTIR-ATR, NTA, DSC, XRD and SANS provided details on their structure and physicochemical stability over time. Interestingly, one optimized pre-formulation (CP-TRANS/TTC) showed phase-separation after 4 months, as predicted by Raman imaging that detected lack of miscibility between its solid (cetyl palmitate) and liquid (Transcutol) lipids. SANS analyses identified lamellar arrangements inside such nanoparticles, the thickness of the lamellae been decreased by TTC. As a result of this combined approach (DOE and biophysical techniques) two optimized pre-formulations were rationally selected, both with great potential as drug delivery systems, extending the release of the anesthetic (> 48 h) and reducing TTC cytotoxicity against Balb/c 3T3 cells.

SUBMITTER: Castro SR

PROVIDER: S-EPMC8563806 | biostudies-literature | 2021 Nov

REPOSITORIES: biostudies-literature

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A pre-formulation study of tetracaine loaded in optimized nanostructured lipid carriers.

Castro Simone R SR Ribeiro Lígia N M LNM Breitkreitz Márcia C MC Guilherme Viviane A VA Rodrigues da Silva Gustavo H GH Mitsutake Hery H Alcântara Ana C S ACS Yokaichiya Fabiano F Franco Margareth K K D MKKD Clemens Daniel D Kent Ben B Lancellotti Marcelo M de Araújo Daniele R DR de Paula Eneida E

Scientific reports 20211102 1

Tetracaine (TTC) is a local anesthetic broadly used for topical and spinal blockade, despite its systemic toxicity. Encapsulation in nanostructured lipid carriers (NLC) may prolong TTC delivery at the site of injection, reducing such toxicity. This work reports the development of NLC loading 4% TTC. Structural properties and encapsulation efficiency (%EE > 63%) guided the selection of three pre-formulations of different lipid composition, through a 2<sup>3</sup> factorial design of experiments ( ...[more]

PMID: 34728779

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A pre-formulation study of tetracaine loaded in optimized nanostructured lipid carriers.

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A pre-formulation study of tetracaine loaded in optimized nanostructured lipid carriers.

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