Antinociceptive activity of liposome-entrapped calcitonin by systemic administration in mice

Porcine calcitonin (pCT) encapsulated in sulfatide-containing reverse-phase evaporation vesicles (REVs) was shown to induce long-lasting and dose-dependent antinociceptive effect by systemic injection in mice. Its antinociceptive activity is found to be dependent on the route of administration. In contrast, neither unencapsulated pCT nor pCT encapsulated in sulfatide-free REVs was effective. These results suggest that pCT entrapped in sulfatide-containing liposomes might be able to cross the blood-brain barrier (BBB) and to produce central antinociception in mice.