Topical Delivery Enhancement with Multilamellar Liposomes into Pilosebaceous Units: I. In Vitro Evaluation Using Fluorescent Techniques with the Hamster Ear Model

• Published in: Journal of investigative dermatology Vol. 99; no. 1; pp. 108 - 113
• Main Authors: Lieb, Linda M, Ramachandran, Chandrasekharan, Egbaria, Kamel, Weiner, Norman
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.07.1992
• Subjects: Administration, Topical; Animals; Cricetinae; Drug Delivery Systems; Ear; Fluoresceins - administration & dosage; Hair; Liposomes; Mesocricetus; Microscopy, Fluorescence; Models, Biological; Sebaceous Glands
• ISSN: 0022-202X; 1523-1747
• DOI: 10.1111/1523-1747.ep12611886

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 24h 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.