title: Method for predicting human intestinal first-pass metabolism of UGT substrate compounds.
abstract: 1. As intestinal glucuronidation has been suggested to generate the low oral bioavailability (F) of drugs, estimating its effects would be valuable for selecting drug candidates. Here, we investigated the absorption and intestinal availability (F(a)F(g)) in animals, and intrinsic clearance via UDP-glucuronosyltransferase (UGT) in intestinal microsomes (CL(int,UGT)) for three drug candidates possessing a carboxylic acid group, in an attempt to estimate the impact of intestinal glucuronidation on F and select potential drug candidates with high F in humans. 2. The F(a)F(g) values of the three test compounds were low in rats and monkeys (0.16-0.51), and high in dogs (≥0.81). Correspondingly, the CL(int,UGT) values were high in rats and monkeys (101-731 µL/min/mg), and low in dogs (≤ 59.6 µL/min/mg). A good inverse correlation was observed between F(a)F(g) and CL(int,UGT), suggesting that intestinal glucuronidation was a major factor influencing F(a)F(g) of these compounds. 3. By applying this correlation to F(a)F(g) in humans using human CL(int,UGT) values (26.9-114 µL/min/mg), compounds 1-3 were predicted to have relatively high F(a)F(g). 4. Our approach is expected to be useful for estimating the impact of intestinal glucuronidation on F in animals and semiquantitatively predicting human F for drug candidates.
authors.affiliation: Analysis and Pharmacokinetics Research Laboratories, Astellas Pharma Inc., Ibaraki, Japan. takako-furukawa@astellas.com
authors.forename: Takako
authors.initials: T
authors.lastname: Furukawa
authors.forename: Katsuhiro
authors.initials: K
authors.lastname: Yamano
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Naritomi
authors.forename: Kohichiro
authors.initials: K
authors.lastname: Tanaka
authors.forename: Shigeyuki
authors.initials: S
authors.lastname: Terashita
authors.forename: Toshio
authors.initials: T
authors.lastname: Teramura
mesh_terms: D061605:Administration, Intravenous; D000284:Administration, Oral; D000818:Animals; D001671:Biochemistry / Q000379:methods*; D004285:Dogs; D020719:Glucuronides / Q000008:administration & dosage / Q000737:chemistry / Q000378:metabolism* / Q000493:pharmacokinetics; D014453:Glucuronosyltransferase / Q000378:metabolism*; D000882:Haplorhini; D006801:Humans; D007413:Intestinal Mucosa / Q000378:metabolism*; D007527:Isoenzymes / Q000378:metabolism; D008297:Male; D008567:Membranes, Artificial; D055442:Metabolome; D008861:Microsomes / Q000378:metabolism; D010539:Permeability; D051381:Rats; D017207:Rats, Sprague-Dawley; D011994:Recombinant Proteins / Q000378:metabolism; D012015:Reference Standards; D013379:Substrate Specificity
chemical_list: D020719:Glucuronides; D007527:Isoenzymes; D008567:Membranes, Artificial; D011994:Recombinant Proteins; D014453:Glucuronosyltransferase