Methods and compositions for investigating multiple drug-drug transporter interactions

A kit comprising an ex vivo system for use in determining multiplex interactions between a candidate drug and two or more drug transporters in an intestinal tissue explant, the kit comprising:

• (i) an intestinal tissue explant comprising intestinal epithelium from a large, non-human, mammalian gastrointestinal tract, wherein the intestinal epithelium comprises epithelial cells having a polarity in the tissue explant and two or more intact drug transporters, wherein the tissue explant provides a luminal surface and a basolateral surface, and wherein the polarity of the epithelial cells is maintained in the tissue explant;
• (ii) two or more agents for use in reducing or eliminating expression of at least two drug transporters selected from:
• p-gp, BCRP, MRP2, MCT1, and PEPT1;
• and
• (iii) instructions for use of the system to determine multiplex interactions between the candidate drug and the two or more drug transporters, wherein the instructions comprise contacting the intestinal tissue explant with the candidate drug before and after expression of the two or more drug transporters is reduced or eliminated in the intestinal tissue explant.

A method for determining multiplex interactions between a candidate drug and two or more drug transporters, comprising:

• (i) obtaining an intestinal tissue explant comprising intestinal epithelium from a large, non-human, mammalian gastrointestinal tract, wherein the tissue explant provides a luminal surface and a basolateral surface, wherein the intestinal epithelium comprises epithelial cells having a polarity in the tissue explant and two or more intact drug transporters located at the luminal surface of the tissue explant and is selected from the group:
• p-gp, BCRP, MRP2, MCT1, and PEPT1, and wherein the polarity of the epithelial cells is maintained in the tissue explant;
• (ii) contacting the tissue explant with two or more agents for reducing or eliminating expression of the two or more drug transporters to generate a modified tissue explant;
• (iii) contacting the tissue explant of (i) or the modified tissue explant of (ii) with the candidate drug;
• (iv) determining adsorption of the candidate drug by detecting the presence of the drug at the luminal surface and at the basolateral surface, wherein presence of the drug at the basolateral surface indicates ability of the drug to be absorbed through the tissue explant;
• and
• (v) comparing absorption between the tissue explant, modified or unmodified,
• thereby determining multiplex interactions between the candidate drugs and the two or more drug transporters.

A method for investigating known multiplex interactions between a candidate drug and two or more drug transporters, comprising:

• (i) obtaining an intestinal tissue explant comprising intestinal epithelium from a large, non-human, mammalian gastrointestinal tract, wherein the intestinal epithelium comprises epithelial cells having a polarity in the tissue explant and the two or more drug transporters, wherein the tissue explant provides a luminal surface and a basolateral surface, and wherein the polarity of the epithelial cells is maintained in the tissue explant;
• (ii) contacting the tissue explant with two or more agents for reducing or eliminating expression of the two or more drug transporters to generate a modified tissue explant, wherein the two or more drug transporters are reduced or eliminated individually or in combination;
• (iii) contacting the tissue explant of (i) or the modified tissue explant of (ii) with the candidate drug;
• (iv) determining adsorption of the candidate drug by detecting the presence of the drug at the luminal surface and at the basolateral surface, wherein presence of the drug at the basolateral surface indicates ability of the drug to be absorbed through the tissue explant;
• and
• (v) comparing absorption between the tissue explant, modified or unmodified,
• thereby investigating the known multiplex interactions between the candidate drug and two or more drug transporters.

A method for determining the effect of two or more drugs utilizing a drug transporter of interest on absorption of at least one of the drugs through an intestinal tissue explant, comprising:

• (i) obtaining an intestinal tissue explant comprising intestinal epithelium from a large, non-human, mammalian gastrointestinal tract, wherein the intestinal epithelium comprises epithelial cells having a polarity in the tissue explant and at least one intact drug transporter, wherein the tissue explant provides a luminal surface and a basolateral surface, and wherein the polarity of the epithelial cells is maintained in the tissue explant;
• (ii) contacting the tissue explant with a first drug known to interact with the drug transporter of interest and a second drug known to interact with the drug transporter of interest;
• (iii) determining adsorption of the first drug by detecting the presence of the drug at the luminal surface and at the basolateral surface, wherein the presence of the drug at the basolateral surface indicates absorption of the drug through the tissue explant;
• and
• (iv) comparing the absorption of the first drug in the presence and absence of the second drug,
• thereby determining the effect of two or more drugs utilizing the drug transporter of interest on absorption of the first drug through an intestinal tissue explant.