Preparation and evaluation of proliposomes containing salmon calcitonin.

Salmon calcitonin (sCT)-containing proliposomes were prepared by penetrating a methanol-chloroformic solution of sCT and phosphatidylcholine (PC) into microporous sorbitol particles, followed by vacuum evaporation of the solvent. As a result, sCT proliposomes with free-flowing flowability were obtained. On contact with water, the proliposomes were rapidly converted into a liposomal dispersion, in which a certain amount of sCT was entrapped by the liposomes. The apparent permeability of sCT across Caco-2 cell monolayers was increased as the result of incorporating sCT into the proliposomes, suggesting that the pharmacokinetics of sCT would be modified through the administration of proliposomes. This is the first study that reports the successful loading of sCT, a protein drug, in proliposomes. The development of various dosage forms of sCT, especially solid dosage forms, appears be feasible using proliposomes.