title: Comparison of the metabolism of diltiazem following percutaneous, subcutaneous, oral and intravenous administration.
abstract: The metabolism of diltiazem hydrochloride following percutaneous administration was compared with that following administration orally and by injection, to ascertain possible advantages in the percutaneous administration of ionizable, water-soluble drugs. The various routes of administration gave rise to markedly differing ratios of diltiazem and deacetylated diltiazem in plasma. The ratio of the AUC values for the two substances was 0.3 (intact skin) and 0.5 (stripped skin) following percutaneous administration, 0.2 following injection, and 0.8 following oral administration of diltiazem. Our results suggest that metabolism may be reduced in routes of administration that lead to very rapid drug absorption and/or rapid clearance from blood. HPLC chromatograms of plasma showed that the number and amounts of metabolites were less when diltiazem was given percutaneously rather than orally.
mesh_terms: D000279:Administration, Cutaneous; D000284:Administration, Oral; D000818:Animals; D001682:Biological Availability; D002851:Chromatography, High Pressure Liquid; D003640:Dealkylation; D004110:Diltiazem / Q000008:administration & dosage / Q000378:metabolism* / Q000493:pharmacokinetics; D007275:Injections, Intravenous; D007279:Injections, Subcutaneous; D008567:Membranes, Artificial; D011817:Rabbits
chemical_list: D008567:Membranes, Artificial; D004110:Diltiazem