Application of Cyperus esculentus oil in the development of sustained release diclofenac sodium-loaded nanostructured lipid carrier

Abstract

The aim of the work was to develop sustained release diclofenac sodium nanostructured lipid carrier (NLC) using tigernut oil (TNO), solid lipids and polyethylene glycol 4000 (PEG 4000) and to evaluate the properties of the formulations. Structured lipids containing tiger nut oil, Softisan®154 and Phospholipon® 90H at varying ratios were prepared by fusion and used as the lipid carrier in formulating the NLC. PEGylated lipid carriers were also employed and the physicochemical properties of these formulations were studied using standard methods including particle size and polydispersity index, encapsulation efficiency, loading capacity and drug release. The results revealed some monodispersed nano-sized formulations that were stable over time. Particle size ranged from 75.22 ± 22.72 nm to 78.11 ± 32.73 nm. High encapsulation efficiency of about 92 % was obtained confirming the suitability of the TNO based carrier.  In vitro drug release in simulated intestinal fluid (pH 7.2) revealed that PEGylated diclofenac sodium-loaded NLC exhibited significantly higher sustained release properties than the non-PEGylated formulations (p <0.05). The results of the drug release kinetics models revealed that the NLC followed a mixed order release kinetic. Hence, the findings in this work showed that TNO could be used as a lipid carrier matrix in combination with other solid lipids for the development of sustained release diclofenac sodium-loaded nanostructured lipid carrier.