(99M)TECHNETIUM-STANNOUS OXINATE AS MARKER OF LIPOSOME FORMULATIONS

Liposomes associated with tin(II) dioxinate were prepared from egg yol k phosphatidylcholine and cholesterol as sterile and pyrogen free mult ilamellar or unilamellar vesicles. Complexing of liposomal tin(II) dio xinate with Tc-99m attained 98% of the added radioactivity. Thirty per cent Tc-99m were released during 24-h incubation in biological fluids. The absence of tin colloids seen by electron microscopy and the stabi lity of liposomal phospholipid and tin(II) dioxinate during 72-h incub ation at 37 degrees C in plasma and cerebrospinal fluid would allow sa fe and reliable scintigraphic liposome pharmacokinetic studies. Copyri ght (C) 1996 Elsevier Science Inc.