Optimization of Diclofenac Sodium-Loaded Nanostructured Lipid Carriers (NLCs) Using the Box-Behnken Design

Abstract

This study aimed to prepare diclofenac sodium (DCF)–loaded nanostructured lipid carriers (NLCs) (DCF-loaded NLCs) for optimizing the NLCs by using the Box-Behnken design. A hot emulsification method using an ultrasonic probe was employed to prepare DCF-loaded NLCs. The active ingredient, solid lipid, oil, and emulsifier were DCF, glyceryl monostearate (GMS) (X1), oleic acid (X2), and polysorbate 80 (X3), respectively. The DCF-loaded NLCs had particle sizes of 69.29–187.3 nm. The polydispersity index (PDI) was in the range of 0.216–0.516, indicating a relatively narrow size distribution. The zeta potential of all formulations revealed the negative charge and ranged between -26.0 and -42.13 mV. The percentage encapsulation efficiency (%EE) was 92.71%–104.21%. The responses of all model formulations were created and the optimized formulation was selected by Design-Expert® software. The optimal formulation was composed of 2 g GMS, 0.926 g oleic acid, and 2.724 g polysorbate 80. The particle size and PDI experimental values with the optimal formulation did not differ from those predicted and were within the 95% CI. Therefore, the Box-Behnken design could be efficient in formulating and optimizing DCF-loaded NLCs.