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Evidence suggesting liposomal delivery into the pilose-baceous 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 μl of the following test formulations, each containing ≈ 100 μg/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. [ABSTRACT FROM AUTHOR]