Availability of norethisterone acetate from combined oral contraceptive tablets

The availability of norethisterone acetate in HCl (0.1 mol/l) from combined oral contraceptive tablets in the presence of certain proprietary preparations and adsorbent drugs which are used as antacids, intestinal adsorbents and for peptic ulcer was investigated. The percent dissolution of the hormone in the presence of these drugs was greatly reduced depending mainly on the nature of the adsorbent drugs.