Although the principle of ISFI is so attractive, key issues remain to be solved. They include (i) variability of the implant shape and structure, (ii) avoidance of burst release during implant formation, and (iii) toxicity issues.
Unfortunately, until now our knowledge concerning the detailed processes of the implant formation is still very limited. This is due to the fact that the processes of implant formation and degradation, drug release and tissue response are complex, heterogeneous, interconnected and not easy to follow, especially in vivo. Despite this statement, many efforts are made in industry and academia to improve current approaches. New materials and approaches enter the preclinical and clinical phases and one can be sure, that ISFI will gain further clinical importance within the next years.