Preparation, characterization and pharmacokinetics of liposomes-encapsulated cyclodextrins inclusion complexes for hydrophobic drugs

Liposomes- encapsulated indomethacin/ cyclodextrins ( IMC/ CD) inclusion complexes were prepared. The characteristics and pharmacokinetics of the combined system were investigated. The high drug entrapment values of 2.38 +/- 0.16 mu g/mg and 2.48 +/- 0.12 mu g/mg for liposomes-encapsulated IMC/beta-CD and IMC/HP-beta-CD inclusion complexes were achieved, as only 1.60 +/- 0.09 mu g/ mg for conventional liposomes. Encapsulating IMC/CD inclusion complexes into liposomes resulted in a slow release of drug. Following intravenous administration, both liposomes- encapsulated inclusion complexes showed significantly improved AUC(0-infinity) compared with that of conventional liposomes ( p < 0.05). After intramuscular administration, Cmax has been increased to 5.21 +/- 1.14 mu g . ml(-1) and 6.02 +/- 1.22 mu g . ml(-1) for liposomes- encapsulated IMC/beta-CD and IMC/HP-beta-CD inclusion complexes, respectively, whereas only 2.43 +/- 0.69 mu g . ml(-1) for liposomes- encapsulated free drug ( p < 0.01).