title: Elastic vesicles for transdermal drug delivery of hydrophilic drugs: a comparison of important physicochemical characteristics of different vesicle types.
abstract: The aim of this study is to evaluate the influence of different lipid vesicular systems on the skin permeation ability of hydrophilic molecules, and understand if and which vesicle physicochemical properties may be used as predictive tools. Calcein and carboxyfluorescein were used as hydrophilic drug models. All vesicles (conventional liposomes [CLs], transfersomes [TRs] and invasomes [INVs]), were characterized for particle size distribution, zeta-potential, vesicular shape and morphology, encapsulation efficiency, integrity, colloidal stability, elasticity and finally in vitro human skin permeation. Dynamic light scattering (DLS) and cryo-transmission electron microscopy (cryo-TEM) defined that almost all vesicles had spherical structure, low polydispersity (PI < 0.2) and nanosize. Elasticity values (measured by extrusion through membranes) were in the order INVs > TRs > CLs. Three vesicle types were selected (having different elasticity) and in vitro skin permeation experiments demonstrated that calcein permeation was minimal from an aqueous solution, slightly enhanced from CLs, and enhanced by 1.8 and 7.2 times from TRs and INVs, respectively. Permeation and elasticity values were correlated by rank order but not linearly, indicating that elasticity can be used as a crude predictive tool for enhancement of skin transport. Drug encapsulation efficiency was not found to be an important factor in the current study.
authors.affiliation: Laboratory of Pharmaceutical Technology, Department of Pharmacy, University of Patras, Rio 26510, Greece.
authors.forename: Vassiliki
authors.initials: V
authors.lastname: Ntimenou
authors.forename: Alfred
authors.initials: A
authors.lastname: Fahr
authors.forename: Sophia G
authors.initials: SG
authors.lastname: Antimisiaris
mesh_terms: D000279:Administration, Cutaneous; D004337:Drug Carriers / Q000737:chemistry / Q000493:pharmacokinetics; D016503:Drug Delivery Systems; D004548:Elasticity; D005260:Female; D005452:Fluoresceins / Q000008:administration & dosage / Q000737:chemistry / Q000493:pharmacokinetics; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D066298:In Vitro Techniques; D008081:Liposomes / Q000138:chemical synthesis / Q000737:chemistry* / Q000493:pharmacokinetics* / Q000648:ultrastructure; D010316:Particle Size; D010539:Permeability; D012867:Skin / Q000378:metabolism; D012869:Skin Absorption / Q000187:drug effects; D013499:Surface Properties
chemical_list: D004337:Drug Carriers; D005452:Fluoresceins; D008081:Liposomes; C024098:6-carboxyfluorescein; C007740:fluorexon