The present invention discloses a method for producing amorphous solid dispersions in a nanoparticulate form, through solvent controlled co-precipitation, using microfluidization/microreaction technology to promote high energy mixing/interaction at a micro and/or molecular level between the streams involved in the process. Feed streams, solvent and anti-solvent, are fed to an intensifier pump at individually controlled rates and forced to interact to micro-and/or nano-scale within a microreactor. The present invention also discloses amorphous solid dispersions obtained by the method of the invention as well as pharmaceutical compositions containing the same.