“…Tranquilizers (Khalil & Moustafa, 1973), antibiotics Khalil e t al., 1976Khalil e t al., , 1977, antirheumatics , corticosteriods (Naggar e t al., 1977(Naggar e t al., , 1978Khalil & Iwuagwu, 1976), antiepileptics (Naggar & Khalil, 1978), and antidiabetics (Naggar & Khalil, 1980) have also been reported to adsorb to antacids. Other adsorbents that can be present as excipients which may, but not always, result in differences in bioavailability , include talc (Batuyios & Brecht, 1957), kaolin (Batuyios & Brecht, 1957), charcoal (Batuyios & Brecht, 1957Sorby, 1965), and montmorillonite clays (Sorby, 1965;Harris, 1961;Chin e t al., 1969;Wai & Banker, 1966;Varley, 1968;McCinty & Hill, 1975;Carstensen & Su, 1971;Aggag et al, 1977). It must be pointed out that with the montmorillonite clays, not only may chemisorption affect adsorbate-adsorbent interaction, but also ion-exchange interaction and molecular entrapment may be possible.…”