Pharmacokinetics and Tissue Distribution of Recombinant Human Alpha A, D, A/D(Bgl), and I Interferons and Mouse Alpha-Interferon in Mice

The pharmacokinetics and tissue distribution in mice of several recombinant human alpha-interferons [rHuIFN-alpha A, D, I, and A/D(Bgl)] as well as natural mouse alpha-interferon (MuIFN-alpha) were assessed following single intravenous injections. The serum profiles of rHuIFN-alpha A, rHuIFN-alpha D, rHuIFN-alpha A/D(Bgl), and MuIFN-alpha were similar, whereas those following rHuIFN-alpha I showed a much longer terminal elimination phase. Differences in elimination half-life, volume of distribution, and total body clearance between these IFNs were observed. There was appreciable uptake of IFN in the kidney: the amount of each interferon per gram of tissue in the kidney ranges from 1 to 9 times the amount found in the serum. The greatest uptake appeared with rHuIFN-alpha D, followed by rHuIFN-alpha A, rHuIFN-alpha A/D(Bgl), and MuIFN-alpha. The only exception was rHuIFN-alpha I which showed no uptake into the kidney.