Lactose microparticles with pollen-like or smooth amorphous morphology were produced using the convective antisolvent technique. The pollen-like particles was either composed of straight needle-like or short entwined dendrites. A possible threshold in the antisolvent humidity condition was found in which the smooth microspheres can be produced. Observation of a smooth network like structure suggested that a 'pinched off' mechanism might be one possible route in the formation of the precipitated smooth microspheres. A scenario based interfacial energy analysis elucidated the narrow (semi-monodispersed) size distribution of the precipitated smooth microspheres. (C) 2013 Elsevier B.V. All rights reserved.