Optimisation of orthosiphon stamineus loaded onto nanostructured lipid carrier using D optimal mixture design

Abstract

In this study, the formulation of Orthosiphon stamineus (OS) loaded onto nanostuctured lipid carrier was prepared using melt emulsification homogenisation technique. Glyceryl monostearate and triglyceride were used as solid and liquid lipids respectively. D-optimal mixture design was employed to optimise the formulation of OS loaded into nanostructured lipid carrier. The independent variables were OS extract, solid lipid and liquid lipid, while the dependent variables were particle size, polydispersity index (PDI) and encapsulation efficiency. Multiple correlation coefficient (R2) obtained for particle size, PDI and encapsulation efficiency was 0.9404, 0.9138 and 0.8754. All three models are significant and the lack of fit for all dependent variables was not significant. Solid lipid was the most influential factor for particle size. For PDI, OS was the dominant factor. Meanwhile liquid lipid is the most influential factor toward the encapsulation efficiency. The optimum formulation of OS loaded nanostructured lipid carrier is 4 % of OS, 1 % of solid lipid and 5 % of liquid lipid.