Comparative study of liposomes, transfersomes, ethosomes and cubosomes for transcutaneous immunisation: characterisation and in vitro skin penetration.
OBJECTIVE
Lipid colloidal vaccines, including liposomes, transfersomes, ethosomes and cubosomes, were formulated, characterised and investigated for their ability to enhance penetration of a peptide vaccine through stillborn piglet skin in vitro.


METHODS
Liposomes and transfersomes were formulated using a film-hydration method, ethosomes using a modified reverse phase method and cubosomes using a lipid precursor method. The size, zeta potential, peptide loading and interfacial behaviour of the formulations were characterised. Skin penetration studies were performed using Franz diffusion cells with piglet skin as the membrane. The localization of peptide in the skin was examined using confocal laser scanning microscopy.


RESULTS
The various formulations contained negatively charged particles of similar size (range: 134-200 nm). Addition of the saponin adjuvant Quil A to the formulations destabilised the monolayers and reduced peptide loading. Cubosomes and ethosomes showed superior skin retention compared with the other systems. Confocal laser scanning microscopy showed greater peptide penetration and accumulation in the skin treated with cubosomes and ethosomes. With the other systems peptide was only located in the vicinity of the hair follicles and within the hair shaft.


CONCLUSIONS
We conclude from the in-vitro studies that cubosomes and ethosomes are promising lipid carriers for transcutaneous immunisation.
New Zealand's National School of Pharmacy, University of Otago, Dunedin, New Zealand.
Teerawan
T
Rattanapak
Katie
K
Young
Thomas
T
Rades
Sarah
S
Hook
D000276:Adjuvants, Immunologic / Q000737:chemistry; D000818:Animals; D003102:Colloids; D016503:Drug Delivery Systems; D008055:Lipids / Q000737:chemistry; D008081:Liposomes; D018613:Microscopy, Confocal; D010316:Particle Size; D010455:Peptides / Q000008:administration & dosage / Q000276:immunology / Q000493:pharmacokinetics; D062605:Quillaja Saponins; D012503:Saponins / Q000737:chemistry*; D012869:Skin Absorption; D013552:Swine; D022223:Vaccines, Subunit / Q000008:administration & dosage / Q000493:pharmacokinetics*
D000276:Adjuvants, Immunologic; D003102:Colloids; D008055:Lipids; D008081:Liposomes; D010455:Peptides; D062605:Quillaja Saponins; D012503:Saponins; D022223:Vaccines, Subunit; C046386:Quil A