Drug was released by pH 6 after an 8-day pre-incubation as measured by LC-MS over 8 hours (A). In BMDMs (B) or C166 endothelial cells (C), treatments (equivalent doses of 40 nM DXM) were added six (B) or eight (C) days before first stimulations. Stimulation consisted of LPS (0.1 μg/ml) for 2–3 hours, and then MSU crystals were added (0.2 mg/ml) overnight, and supernatants were saved at −80°C and then analyzed for IL-1β (B) or CXCL1 (C) levels by ELISA. Data is presented as pg/ml, (***p < 0.001, *p < 0.05).