Monocytes and MDM were loaded with homogenized (H1008, H2014) or wet milled (M1002, M2006) formulations at 0.1 mM and 0.5 mM. Following drug loading, toxicity was assessed over 48 hrs by alamarBlue™ assay. Control consisted of untreated cells. Compared to homogenized formulations, wet milled IDV and RTV were significantly more toxic to monocytes and MDM. Comparison of milled nanoART with all homogenized formulations gave similar results. For each experimental condition, n = 3. Figure shown is representative of 3 independent experiments (#P<0.05, *P<0.01; **P<0.001).