Table 6: Degradation study of rifaximin in various conditions.

Exposure conditionsDegradation products ( )Recovery (%)a

None (control sample)Not detected100
0.1 M HCl, refluxed (30 min)0.44, 0.4955.39
0.1 M NaOH, refluxed (30 min)0.46, 0.5181.94
3% Hydrogen peroxide, refluxed (30 min)0.4794.95
Wet heat, refluxed (30 min)100
Sunlight (24 h)0.6789.72
UV light, 254 nm (24 h)0.4998.34

replicates for concentration of 1000 ng/band.