Figure shows the number of passes, which equates to the milling time, and the changes in drug particle size during wet-milling by a high-pressure homogenizer at a 20-30-g scale. Nanosuspensions with z-averages of 300-400 nm could be produced with both surfactants. The milling profile showed differences between them, with polysorbate 20 achieving a smaller particle size with fewer passes than those of poloxamer P338. Verma et al. reported that in using microfluidization of a nanosuspension, a medium composition with high drug solubility may lead to Ostwald ripening, which might cause a larger particle size. A comparison of Tween80 (polysorbate 80) and Pluronic F-68 (poloxamer 188) demonstrated a correlation between differences in solubility and particle size, with smaller drug particles obtained using Pluronic F-68, which has lower medium solubility . Other studies of nanosuspensions using Tween 80 and Pluronic F-68 have also reported that Pluronic F68 achieves smaller drug particle sizes. injections, a common administration route, allows administering up to 5 mL. However, in the deltoid muscle, the administration volume is limited to 0.5-2 mL.