DISTRIBUTION OF METHYLENE BLUE AND CHLORDIAZEPOXIDE IN RABBITS

概要

論文の詳細を見る
Apparent partition coefficient (P') for methylene blue (MB) in n-heptane/phosphate buffer (pH 7.4) system and apparent volumes of distribution (V_d') for MB and chlordiazepoxide (CDP) in rabbits were determined. CDP is one of the basic drugs in the region of low P'. Although P'for MB also has a low value (0.0186), V_d, for MB (21.0 l/kg) was higher than that for CDP (1.96 l/kg). This fact could not be explained by the previously proposed model for V_d'-P' relationship which stated that V_d'should have an almost constant value in the region of low P'and required more elaborated model that includes factors other than partition coefficient. Therefore, drug transfer to erythrocyte-fraction for these two drugs was investigated in vivo and in vitro, and protein binding of MB was determined in vitro. Transfer to erythrocytefraction for MB was higher than that for CDP both in vivo and in vitro. Transfer to erythrocytefraction for MB was higher than that for CDP both in vivo and in vitro. However, these results only partly accounted for the high value of V_d'for MB. The extent of binding of MB to bovine serum albumin was comparable to those of other drugs with low P', CDP and antipyrine. Hence, it was considered that protein binding did not contribute to a high V_d' value for MB. These evidences suggest that there may be an interaction between MB and some biological components excluding such protein as BSA in the body.
公益社団法人日本薬学会の論文