Stability parameters ARI CLO Plasma conc. (ng mL-1) Recovery % ± RSDa Plasma conc. (ng mL-1) Recovery % ± RSDa Short term (4 h, room temperature) 20 95.87 ± 2.54 20 98.43 ± 0.87 400 97.32 ± 2.76 400 96.52 ± 1.55 800 93.21 ± 2.21 800 96.32 ± 1.81 Post-preparative (24 h, room temperature) 20 94.32 ± 3.86 20 97.51 ± 1.96 400 92.43 ± 3.53 400 94.85 ± 3.15 800 92.38 ± 4.43 800 95.71 ± 2.87 Freeze - thaw (three cycles) 20 88.30 ± 2.45 20 95.63 ± 3.21 400 91.75 ± 2.03 400 97.92 ± 1.47 800 89.58 ± 1.67 800 94.22 ± 2.85 Long term (-20°C, 30 days) 20 87.74 ± 2.87 20 92.65 ± 2.22 400 87.53 ± 4.36 400 90.84 ± 2.85 800 90.75 ± 4.85 800 88.73 ± 4.23

aAverage of three separate determinations

Table 4: Stability study of ARI and CLO in human plasma by the proposed HPLC method.