The aim of this work was to prepare spray-dried microparticles using Gelucire (R) 44/14 (GLC) and porous calcium silicate (FLR) or spherical crystalline cellulose (M06) to enhance transport of poorly water-soluble pranlukast hemihydrate (PLH) across Caco-2 monolayers. FLR or M06 were added to the PLH-GLC aqueous mixture prepared by adding distilled water at 60 degrees C to a melted mixture of PLH/GLC (1/1) at a PLH-GLC/carrier ratio of 1/1 or 1/17. Spray-dried FLR microparticles have the PLH-GLC solid dispersion (SD) in their pores and spray-dried M06 microparticles have the PLH-GLC SD on their surface. The dissolutions of PLH from the spray-dried FLR (SD/FLR = 1/1), spray-dried M06 (SD/M06 = 1/1), and spray-dried M06 (SD/M06 = 1/17) microparticles in Tween 80 aqueous solution were markedly fast. The transport of PLH from the spray-dried FLR (SD/FLR = 1/1) across Caco-2 monolayers was hardly observed. The transport of PLH across Caco-2 monolayers from the spray-dried M06 (SD/M06 = 1/17) increased with time, and the transport was significantly higher compared to that from PLH powder. The addition of polyethylene glycol 1500 into GLC of the spray-dried M06 was effective to increase the transport of PLH across Caco-2 monolayers. Spray-dried microparticles of PLH using GLC and M06 are a feasible means of enhancing transport across Caco-2 monolayers. (C) 2011 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.