title: Topical delivery enhancement with multilamellar liposomes into pilosebaceous units: I. In vitro evaluation using fluorescent techniques with the hamster ear model.
abstract: Evidence suggesting liposomal delivery into the pilosebaceous unit of the male Syrian hamster ear membrane was found using two fluorescent techniques, quantitative fluorescence microscopy (QFM), and a scraping method where the various tissue strata of treated skin are analyzed using fluorescence spectrophotometry. Whole ears were mounted on Franz diffusion cells and treated for 24 h with 40 microliters of the following test formulations, each containing approximately 100 micrograms/ml carboxyfluorescein (CF): i) multilamellar phosphatidylcholine: cholesterol: phosphatidylserine liposomes; ii) HEPES buffer (pH, 7.4); iii) 5% propylene glycol; iv) 10% ethanol; v) 0.05% sodium lauryl sulfate; and vi) a suspension of the same lipids used to form the liposomes that were not processed so as to produce a bilayer configuration. Topical application of the liposomally based formulation resulted in a significantly higher accumulation of CF in the pilosebaceous units than the application of any of the other non-liposomal formulations. There was excellent correlation between the two analytical methods used to determine CF deposition into the sebaceous glands.
authors.affiliation: College of Pharmacy, University of Michigan, Ann Arbor 48109-1065.
authors.forename: L M
authors.initials: LM
authors.lastname: Lieb
authors.forename: C
authors.initials: C
authors.lastname: Ramachandran
authors.forename: K
authors.initials: K
authors.lastname: Egbaria
authors.forename: N
authors.initials: N
authors.lastname: Weiner
mesh_terms: D000287:Administration, Topical; D000818:Animals; D006224:Cricetinae; D016503:Drug Delivery Systems; D004423:Ear; D005452:Fluoresceins / Q000008:administration & dosage; D006197:Hair; D008081:Liposomes; D008647:Mesocricetus; D008856:Microscopy, Fluorescence; D008954:Models, Biological; D012627:Sebaceous Glands
chemical_list: D005452:Fluoresceins; D008081:Liposomes; C024098:6-carboxyfluorescein