Figure 1: IPX-750 is found in significant concentration in the blood of rats after intraperitoneal (i.p.) injection at 200mg/kg. Rats were injected with IPX-750 i.p. followed by collection of blood samples (collected into EDTA; final 2-4mM) at 30, 60, and 90 min post injection. Blood samples were separated into cell (a) and plasma (b) fractions by centrifugation at 10K for 10 min. Samples were lyophilized and IPX-750 in the lyophilized fractions was extracted into 100μl TMS derivatization reagent, PAGP internal standard was added and 1μl was injected for GC/MS analysis. GC peaks representing IPX-750 mass ions or PAGP mass ions were digitally selected and their integrated peak areas determined. A “peak ratio” was obtained by dividing the total IPX-750 GC peak area by the total area of the PAGP peaks. The amount of IPX-750 in a sample was determined by multiplying the “peak ratio” times the amount of PAGP internal standard injected onto the GC column, i.e., 10ng in 1μl. The amount of IPX-750 in each sample is expressed at μg/ml of blood (before separation into cell and plasma) and compared with levels in saline injected animals using ANOVA. n=3; all showed significance; p ≤ 0.001.