Brucellosis is a common disease between humans and livestock, and treatment and relapse of this disease is one of the major challenges. The aim of this study was to evaluate the therapeutic effect of doxycycline-loaded solid lipid nanoparticles (DOX-SLN) on acute and chronic brucellosis and its effect on serum level of 25-OH-Vitamin D, C-reactive protein (CRP) and biochemical parameters. Methods Double emulsion method was used for synthesis of nanoparticles. Serum levels of vitamin D, CRP,

more »

... protein, albumin and globulin were measured in rats with brucellosis. The therapeutic effect of DOX-SLN was compared with that of free doxycycline. Results The mean size, Zeta potential, PDI, drug loading and encapsulation efficiency of the synthesized nanoparticles were 299±34 nm, -28.7±3.2 mV, 0.29±0.027, 11.2±1.3%, and 94.9±3.2%, respectively. Serum vitamin D levels in rats with chronic brucellosis decreased compared to healthy rats. CRP increased in the acute and chronic stages of brucellosis. Serum levels of total protein and albumin were similar in both stages of the disease but serum globulin levels was increased. Conclusion According to the results, serum level of vitamin D was increased in rats after treatment with DOX-SLN. The use of DOX-SLN as an alternative drug for the treatment of chronic brucellosis is recommended.