Ezetimibe-Loaded Nanostructured Lipid Carrier for Oral Delivery: Response Surface Methodology; In Vitro Characterization and Assessing the Antihyperlipidemic Effect in Rats.

Among the independent risk factors for the occurrence of cardiovascular diseases like atherosclerosis is hyperlipidemia. To decrease cardiovascular events and patient mortality, antihyperlipidemia therapy is crucial. Our study aimed to enhance the solubility of the poorly soluble lipid-lowering agent ezetimibe (EZ), a member of class II as per the Biopharmaceutics Classification System (BCS). The drug was formulated as a nanostructured lipid carrier (NLC) employing the ultrasonication technique. A response surface D-optimal design was employed to study the effect of changing the liquid lipid type and the percentage of liquid lipid with respect to total lipid amount on the particle size, zeta potential, percentage entrapment efficiency, and percentage of drug released after 24 h. Nine NLC formulations were prepared and pharmaceutically evaluated, and the optimized NLC formulation was selected, further characterized, and evaluated as well. Optimized EZ-NLC was assessed in the high-fat diet model to induce hyperlipidemia in rats in comparison with the EZ suspension. The results of the optimized formulation showed that the prepared NLCs were spherical with no aggregation having a particle size of 204.3 ± 19.17 nm, zeta potential equal to -32 ± 7.59 mV, and entrapment efficiency of 81.5 ± 3.58% and 72.15 ± 4.58% drug released after 24 h. EZ-NLC significantly decreased the elevated serum lipid parameters, including total cholesterol, triglycerides, and LDL-C, but significantly normalized serum HDL-C levels of rats kept on a high-fat diet. The results demonstrated the improved efficacy of EZ-NLC in ameliorating the elevated serum lipid parameters compared to EZ.