T. Nishihata et Jh. Rytting, ABSORPTION-PROMOTING ADJUVANTS - ENHANCING ACTION ON RECTAL ABSORPTION, Advanced drug delivery reviews, 28(2), 1997, pp. 205-228
Studies of absorption-promoting adjuvants used for the modification of
the barrier function of the rectal membrane are interesting for bioch
emical research as well as providing a basis for the development of ne
w formulations of poorly absorbed drugs such as some moderately large
water soluble drugs and peptides. Compounds such as chelating agents a
nd sulfhydryl depleters increase the rectal absorption of drugs throug
h the paracellular route and transcellular route, respectively, by mod
ifying the barrier function of each route. Salicylate, its derivatives
and fatty acids also increase rectal drug absorption through both rou
tes. Lectin increases rectal absorption of drugs by inducing microvill
ous infusion. With respect to formulation development, ampicillin supp
ositories incorporating sodium caprylate as an absorption promoting ad
juvant were confirmed clinically to be an effective formulation, acid
are a marketed product in Japan. In human trials, administration of in
sulin in a combination with salicylate inhibited postprandial hypergly
cemia in diabetic patients. (C) 1997 Elsevier Science B.V.