Drug-in-cyclodextrin-in-liposomes as a carrier system for volatile essential oil components: Application to anethole.

A combined approach based on cyclodextrin/drug inclusion complex formation and loading into liposomes was applied to improve the effectiveness of liposome loading with essential oils. Hydroxypropyl-β-cyclodextrin/ANE (HP-β-CD/ANE) inclusion complexes were prepared and encapsulated into liposomes (ACL). ANE-double-loaded liposomes (ACL2) were obtained with the HP-β-CD/ANE complex in the aqueous phase and ANE in the organic phase. Liposomes were prepared from saturated (Phospholipon 90H) or unsaturated (Lipoid S100) phospholipids and characterized for size, polydispersity index, zeta potential, morphology, loading rate (LR) and photo- and storage stabilities. All liposome batches were nanometric oligolamellar-type vesicles. Compared to ANE-loaded liposomes, ACL-90H, ACL2-90H and ACL2-S100 displayed significantly increased ANE LR, with ACL2-S100 exhibiting the highest LR. All formulations provided ANE photoprotection, were physically stable after 15months of storage at 4°C (with the exception of ACL2-S100), and retained more than 25% of the ANE initially present in the liposome suspensions.