Development of efavirenz loaded solid lipid nanoparticles: Risk assessment, quality-by-design (QbD) based optimisation and physicochemical characterisation

The purpose of this study was development and characterisation of efavirenz (EFZ) loaded solid lipid nanoparticles (SLN) using QbD approach. Quality target product profile of EFZ loaded SLN were defined and critical quality attributes were identified. SLN were prepared by nanoprecipitation method. Initially, feasibility of SLN formation was studied by using different lipids including glyceryl monostearate, stearic acid and surfactants such as poloxamer 188, tween 80, docusate sodium and sodium lauryl sulphate. A 32 factorial design was employed to optimize EFZ loaded SLN wherein acetone/methanol ratio in organic phase and surfactant concentration were selected as independent variables whereas particle size (PS) and %entrapment efficiency (EE) were selected as responses. PS of SLN was found to be varied from 167.77 to 1166 nm and %EE was in the range of 23.07-88%. DSC thermograms indicated the amorphous state of EFZ in the SLN. The FTIR studies confirmed no interaction among materials used in fabrication of SLN while NMR studies confirmed their incorporation in the SLN. Spherical shape of SLN was confirmed by TEM. This study suggests the importance of implementation of QbD approach for identifying critical process and formulation parameter in order to develop nano based pharmaceutical product. (C) 2017 Elsevier B.V. All rights reserved.