This work was aimed to synthesize novel crosslinked carboxymethyl chitosan nanoparticles (CMCS NPs) containing metformin hydrochloride (MET) using microfluidics (MF) and evaluate their performance for diabetes therapy. The field emission-scanning electron microscopy (FE-SEM) images and dynamic light scattering (DLS) results showed that the NPs average size was 77 ± 19 nm with a narrow size distribution. (351 characters)