Chitosan nano particles synthesized by crosslinking reaction between the ionic gelation of chitosan with TPP (tri-polyphosphate) using Tween 80 surfactant. The reaction takes place through continuous stirring with a magnetic stirring at room temperature for 2 hours. Based on the obtained nano size particles PSA ranged between 215.9 and 272.9 nm with a chemical composition containing the elements C, H, O, N, and some minerals were observed by SEM-EDS. Bioactivity test results showed the concentration of 0.01% b/v has a maximum resistance spectrum. Toxicity tests on white mice with LD50 value compound chitosan nano particles contain no toxic poison
