Background: The development of novel drug delivery systems for herbal drug application has reduced the toxicity and improved their bioavailability. This work evaluated the toxicity of crude ethanolic extract of Morus nigra (CEE-Mn)/CEE-Mn-loaded electrospun fibers and in vitro release profile of encapsulated extract. The electrospun fibers were prepared using ethanolic solution of Eudragit L-100 and CEE-Mn at different concentrations. Scanning Electron Microscopy (SEM) images and Fourier Transform Infra-Red (FTIR) analysis were performed to identify the encapsulation degree.Method: The toxicity was evaluated by single dose toxicity assay, mice orally received CEEMn or CEE-Mn-loaded electrospun fibers (both at concentration of 2.0 g/kg). The in vitro release of CEE-Mn electrospun fibers was evaluated in simulated intestinal fluid solution. Result: The results of SEM of CEE-Mn-loaded electrospun fibers indicated a slick texture (no beads) and the FTIR confirmed the incorporation of CEE-Mn on electrospun fibers of Eudragit L-100. The CEE-Mn and CEE-Mn-loaded electrospun fibers showed a tolerable toxicity and in vitro assays demonstrated a controlled release of CEE-Mn. Conclusion: Thus, the CEE-Mn-loaded in electrospun fibers can be considered as a promising new candidate to be applied in the treatment of several pathologies.