Chemotherapy-induced nausea and vomiting (CINV) typically occurs in two distinct phases: an acute phase, which arises within the first 24 h following chemotherapy, and a delayed phase, which develops between 24 and 120 h afterward. While acute CINV is now effectively controlled using 5-hydroxytryptamine type 3 (5-HT3) receptor antagonists, managing delayed CINV remains a significant clinical challenge. This study was aimed to develop Ondansetron hydrochloride (OND), loaded nanocarriers featuring high encapsulation efficiency (EE), to enable sustained drug release over several days. OND loaded sustained release liposome and lipid polymer hybrid polymeric nanoparticle (LPHNP) were prepared. The prepared formulations were characterized in terms of particle size and distribution, zeta potential, encapsulation efficiency and drug release in an in vitro study. The effects of the type of phospholipids, phospholipid/cholesterol molar ratio, and pH of hydration medium on liposome formulations were examined. In LPHNP formulations, the effect of external water phase volume, phospholipid type, preparation method, and pH of the aqueous phase was evaluated. In vitro cytotoxicity of the formulations was determined using L929 fibroblast cells. Optimum LPHNP formulation and the commercial product (Zofer®) were administered subcutaneously in a single dose to Wistar albino rats. It was found higher Cmax and MRT in LPHNP formulations than Zofer®. In this study, the effectiveness and safety of Ondansetron hydrochloride loaded LPHNP formulations were determined.