Carvedilol poly(d,l)-lactide nanoparticles/microparticles were prepared. The size and morphology of the developed particles were optimized to study the carvedilol release profile by studying the effect of organic solvents and polymer amount through atomic force microscopy analysis. Spherical particles were obtained with a minimum size of 125 nm in the case of acetone and a maximum size of 970 nm in the case of dichloromethane affording microparticles formation. The interaction was confirmed by differential scanning calorimeter and Fourier transform infrared. The in vitro release profile of the multicompartment system (pure carvedilol, loaded nanoparticles and microparticles) has shown a sustained release with Korsmeyer–Peppas with T lag model.