Dextran sulphate sodium nanoparticles with cephalexin were created, lyophilized (LCDNP), and then examined. The LCDNP has a zeta potential of -21.8 ± 8.36 mV, a PDI of 0.257, and a PDI percentage of 68.8. The size of a single particle in LCDNP was 260.4 ± 74.53 nm, and the conductivity of the nanoparticles in colloidal solution was 2.37 mS/cm. The zeta average nano size of LCDNP was 318.8 z. d.nm. Differential scanning calorimetry (DSC) has shown that LCDNP exhibits distinct endothermic peaks at 287.79 C. At 211.79 °C, the thermogravimetric analysis (TGA) revealed that LCDNP had lost 95% of its weight. When LCDNP was subjected to XRD analysis, it revealed distinct peaks at 2 as 10.7, 11.5, 12.5, 19.8, 21.4, 25.5, 29.3, 34.3, 39.8, and 41.5, indicating crystalline structure. The zero-order kinetics of the cephalexin release from LCDNP demonstrated a linear release with 38% of the medication released in 7 hours. When tested against tested human pathogenic bacteria, LCDNP's antibacterial impact shown broad-spectrum efficacy. The specified study showed LCDNP to be a promising antibacterial agent.