HIA (Human Intestinal Absorption) is calculated from the sum of bioavailability and absorption evaluated from the ratio of
excretion or cumulative excretion in urine, bile and faeces which is the prime barrier towards good bioavailability [30,42,43]. This percentage as obtained from preADMET at pH 7.4 showed that all twenty five steroids are well absorbed compounds as their percentage of absorption >70%. Also, various in vitro methods are employed for evaluating the intestinal absorption parameters of the drug candidates such as Human colon adenocarcinoma (Caco-2) and Madin-Darby canine kidney cell (MDCK) which are two such highly recommended and reliable in vitro model for predicting absorption of oral drugs [27,28]. Caco-2 cells are obtained from human colon adenocarcinoma possessing multiple drug transport
pathways through the intestinal epithelium. Compounds having Pcaco-2 (nm/sec) values less than 4 are the ones with low permeability. Middle permeability is shown when Caco-2 values lies within 4–70 and compounds exhibiting values more than 70 are the highly permeable ones. All steroids showed middle permeability to Caco-2 model but low permeability to MDCK as compounds having PMDCK (nm/sec) values lower than 25 are the low permeable ones.