Some authors use Tween 80 in the broth medium to enhance oil solubility (30). In the current study, MIC of Tween 80 against M. tuberculosis H37Rv determined in the antimycobacterial assay (0.99%) was much higher than the concentration used for solubilizing oil (0.001%). Therefore, the addition of Tween 80 to the culture medium did not alter the MIC values obtained.