Fig. 1From: An in vivo pharmacokinetic study of metformin microparticles as an oral sustained release formulation in rabbitsScanning electron microscopy (SEM) images of the surfaces of the investigated metformin-loaded PLA microparticles after lyophilization. The SEM micrograph shows the large distribution of microparticle sizes, ranging from 1 to 55 µm (1010 × magnification, scale bar = 10 μm). PLA: Poly (lactic acid)Back to article page