The effect of surface charge on the disposition of liposome-encapsulated gentamicin to the rat liver, brain, lungs and kidneys after intraperitoneal administration

The disposition of gentamicin to the normal rat brain, lung, kidney and liver was studied at intervals of 1, 2, 4, 6 and 8 h after intraperitoneal injection of gentamicin encapsulated in positive, negative and neutral liposomes. Compared with the control, which was treated with free gentamicin, liposomes were associated with higher concentrations of gentamicin in the brain and liver, while concentrations were lower in the kidney. The average concentrations of gentamicin in the liver and the brain were highest with positive liposomes, while, gentamicin concentrations in the kidneys and lungs were not influenced by surface charge of the liposomes. These observations have important implications on the selective delivery of gentamicin to tissues and on the intraperitoneal route of administration.