Fig. 1

a Particle size distribution for imipenem/cilastatin loaded polycaprolactone nanoparticles as measured by laser diffraction particle analyzer. b Particle size distribution for imipenem/cilastatin loaded polylactide-co-glycolide nanoparticles as measured by laser differaction particle analyzer. c Image for imipenem/cilastatin loaded polycaprolactone nanoparticles as measured by atomic forced microscopy (AFM), a 2-D view and d the image in 3-D