Electrospinning Process Technology

Personnel: Indrani Bhattacharyya, Keith Forward

Electrospinning has proven to be an extremely promising technology in recent times. However, the typically low production rate from a conventional needle electrospinning system has made it difficult to employ this process in industrial settings. To overcome this issue, several “needleless” or “free surface” electrospinning techniques have been investigated over the past few years, in which multiple jetting is promoted simultaneously from a sufficiently large area of liquid surface. One such technique involves jetting from the liquid droplets that form on a wire electrode as it exits a bath of liquid with an entrained liquid coating1. This technique has been successfully utilized in our lab for large production of electrospun mats from polymer solutions.

Figure 1: Free Surface Electrospinning from a wire electrode.
Figure 1: Free Surface Electrospinning from a wire electrode.

 

Our aim is to extend this technology to a broad range of solution systems and develop a robust model for the “free surface electrospinning” technique. With the vision to incorporate Active Pharmaceutical Ingradients (APIs) into the solution systems and hence in the produced final electrospun mat, we propose to extend the benefits of free surface electrospinning technology to manufacturing processes in the pharmaceutical industry. The dissolution rates of excipients offer means to control the release rates of the incorporated APIs. The choice of polymer, concentration of polymer in solution and process parameters allow us to attain the desired release rates of APIs. The mechanical properties of the electrospun mats will also be studied for purposes of integration with folding/tableting operations.

In a major recent development, we have demonstrated the capability to form electrospun fiber mats comprising fibers with core-shell morphology using free surface electrospinning. In this case, the electrode wire passes through two immiscible layers of liquids. The top solution layer forms the shell and the bottom layer forms the core of the fiber during electrospinning. The solvent of the core layer diffuses through the shell layer during the drying process such that a solid core-shell fiber is formed on the collector. We are pursuing core-shell electrospinning further to find the possibility of applying this technique for sustained release of APIs in pharmaceutical industry.

 

For Further Information

  1. K.M. Forward, G.C. Rutledge, “Free surface electrospinning from a wire electrode”, Chem. Eng. J. 2012, 183, 492-503.
    Abstract and full text, courtesy of ScienceDirect
  2. K.M. Forward, A. Flores, G.C.Rutledge, “Production of Core/Shell Fibers by Electrospinning from a Free Surface,” Chem. Eng. Sci. 2013. (in press)
  3. P.K. Battacharjee, T.M. Scheider, M.P. Brenner, G.H. McKinley, G.C. Rutledge, “On the Measured Current in Electrospinning”, J. Appl. Phys. 2010, 107, 044306.
    Abstract and full text, courtesy of American Institute of Physics