Nanostructured Lipid Carrier Containing CNS Acting Drug: Formulation, Optimization and Evaluation

The aim of the present study was to formulate, optimize and evaluate nanostructured lipid carrier (NLC) containing duloxetine (DLX-NLC). NLCs were developed using homogenization followed by ultrasonication. Formula of DLX-NLC was optimized by response surface methodology using Box-Behnken design model. The prepared DLX-NLCs were evaluated for particle size, particle size distribution, polydispersity index (PDI), entrapment efficiency (EE), drug loading (DL), surface morphology, in vitro release and stability studies. An attempt was made to evaluate the permeability of DLX-NLC through porcine nasal mucosal membrane so that it can be targeted to the brain through nose to brain route of drug delivery. The optimized DLX-NLC dispersion exhibited particle size of 125.7 ± 3.24 nm, zeta potential of - 29.4 ± 7.65 mV, EE of 80.26 ± 3.54 %, and DL of 10.98 ± 4.11 %. The lyophilized DLX-NLC revealed particle size of 137.2 ± 2.88 nm, zeta potential of - 31.53 ± 11.21mV, EE of 79.15 ± 4.17 %, and DL of 9.73 ± 3.22 %. The TEM and SEM studies confirmed the spherical shape of DLX-NLC. Both the formulations (DLX-NLC dispersion and lyophilized DLX-NLC) exhibited sustained release of DLX. The result of permeation studies through porcine nasal mucosal membrane confirmed the possibility of delivery of drug - loaded NLCs through nasal route. Furthermore the histological studies revealed no signs of damage on the integrity of the nasal mucosal membrane, thus confirming the safety of the preparation. Keywords: NLC, DLX, sustained release, encapsulation, zeta potential, mucosal permeation