Liposomes Prepared from Synthetic Amphiphiles: I: Their Technetium Labeling and Stability

Abstract

In order to apply liposomes prepared from synthetic amphiphiles containing amino acid residues to radio-pharmaceuticals, their labeling with 99Tc or 99mTc and stability in saline or in serum were investigated. These liposomes were highly labeled by embedding stearylamine-diethylenetriamine pentaacetic acid as a ligand of technetium. The labeling was more efficient at pH 7.0 than at pH 4.0 or 8.5. Among these technetium-labeled liposomes tested, liposomes containing the alanine residue were stable in saline or in 50 % serum at 37 °C for at least 24h. in contrast to liposomes (phosphatidylcholine: cholesterol = 1:1 molar ratio) whose stability had been enhanced by adding cholesterol. © 1989, The Pharmaceutical Society of Japan. All rights reserved.