Device for constant Sc infusion of methotrexate: plasma results in mice

An infusion device is described which permits sc infusion of methotrexate into mice at a constant rate. Physical characteristics of devices ranging in size from 0.27-mm internal diameter X 15 mm long to 1.95-mm internal diameter X 2 mm long are described. Plateau plasma concentrations of methotrexate (1 X 10(-8) M to 1 X 10(-5) M) achieved from infusion rates varying over three orders of magnitude (less than 1- greater than 100 mug/hour) are presented. These data are evaluated in terms of the known toxic effects and pharmacokinetic behavior of this drug.