Advanced Powder Technology, Vol.29, No.12, 2941-2956, 2018
Impact of polymers on the aggregation of wet-milled itraconazole particles and their dissolution from spray-dried nanocomposites
We explore the impact of various polymers and their molecular weight on the stabilization of wet-milled suspensions of itraconazole (ITZ), a poorly soluble drug, and its dissolution from spray-dried suspensions. To this end, ITZ suspensions with SSL, SL, and L grades of hydroxypropyl cellulose (HPC) having molecular weights (MWs) of 40, 100, and 140 kg/mol, respectively, hydroxypropyl methyl cellulose (HPMC E3 with 10 kg/mol), polyvinylpyrrolidone (PVP K30 with 50 kg/mol), sodium dodecyl sulfate (SDS, surfactant), and HPC SL-SDS were wet media milled and spray-dried. Laser diffraction results show that 2.5% HPC SL-0.2% SDS led to the finest ITZ nanosuspension, whereas without SDS, only 4.5% HPC with SL/L grades ensured minimal aggregation. Rheological characterization reveals that aggregated suspensions exhibited pronounced pseudoplasticity, whereas stable suspensions exhibited near Newtonian behavior. Spray-drying yielded nanocomposites with 60-78% mean ITZ loading and acceptable content uniformity. Severe aggregation occurred during milling/drying when 4.5% polymers with MW <= 50 kg/mol were used; their nanocomposites exhibited incomplete redispersion due to slow matrix erosion and released ITZ slowly during dissolution test. Overall, high drug-loaded, surfactant-free ITZ nanocomposites that exhibited immediate release (>80% dissolved in 20 min) were prepared via spray-drying of wet-milled ITZ with 4.5% HPC SL/L. (C) 2018 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).