TilE EFFECT OF ALUMINUM HYDROXIDE GEL (AMPHOJEL) AND HYDRATED ALUMINA POWDER ON THE INTENSITY AND 1)URA- TION OF ACTION OF ANTICHOLINERGIC DRUGS’

It has generally been held that adsorbents reduce the rate of absorption of orally administered drugs, partly by limiting the availability of the drugs and partly by impeding their access to the absorbing surface (Sollmann, 1948). It was assumed, therefore, that the administration of anticholinergic drugs and an adsorbent simultaneously by mouth would result in the production of less sustained levels of drug action. Preliminary experiments with atropine sulfate and hydrated alumina gel (A.mphojel, Wyeth) administered orally to rats, however, demonstrated Un-equivocally that contrary to expectation, this adsorbent did not appreciably limit the availability and activity of the anticholinergic drug but, rather, acted as an intestinal repository and prolonged the duration of its action. This study was extended and included the following anticholinergic drugs: belladonna extract, N-(2’-dimethylamino-2’-methylethyl) phenothiazine methiodide (Phen-ergan methiodide, Wyeth), atropine methyl nitrate (Eumydrine, Winthrop-Stearns), and 9-diethylaminoethyl xanthene-9-carboxylate methobromide (Ban