International Journal of Pharmaceutics 296 (2005) 44–54 In vivo comparison of various liposome formulations for cosmetic application Gabriele Betz a , Angela Aeppli a , Natalia Menshutina b , Hans Leuenberger a, a InstituteofPharmaceuticalTechnology,Pharmacenter,UniversityofBasel,Klingelbergstr.50,4056Basel,Switzerland b DepartmentofCybernetics,MendeleyevUniversityofChemicalTechnologyofRussia,MiusskayaSquare,9Moscow125047,Russia Received 18 June 2004; received in revised form 11 February 2005; accepted 12 February 2005 Available online 8 April 2005 Abstract The interaction of liposome formulations, prepared with phospholipids of different origins (egg and soya), with skin were compared in terms of their effects on skin water content, skin barrier function, and skin elasticity. Short-term effect of four different liposome formulations and two references during 3.5h was investigated non-occlusively on the volar side of the forearm of 10 volunteers, ranging in age from 24 to 32 years. Liposomes composed of different phospholipids showed differing effects on skin humidity. The maximal effect was achieved within 30 min and constant values were reached after 1.5 h for all formulations, however values remained significantly higher than without treatment (p < 0.05) during the whole application time. The best results were obtained with liposome formulations prepared from egg phospholipids, which exhibited a 1.5-fold increase in skin water content (p < 0.05), whereas liposome formulations prepared from soya phospholipids showed no advantage compared to the references. Skin barrier function showed greatest influence within 30 min after application and remained constant after 1.5 h for all formulations. Within the liposome formulations, egg phospholipids showed the highest transepidermal water loss values during the first 30 min, representing the strongest interactions with the skin barrier function, whereas for the other liposome formulations lower transepidermal water loss values were measured. Skin elasticity and tiring effect of the skin was not influenced by any of the formulations, due to the young skin tested. Long-term effect of two different liposome formulations mixed with base cream DAC in two different concentrations during 14 days was investigated non-occlusively on the volar side of the forearm of 10 volunteers, ranging in age from 20 to 25 years. Skin water content was measured daily and the results showed that skin humidity was increased significantly (p < 0.05) for the formulation containing 20% egg phospholipids during 6 days. Liposome formulations prepared with egg phospholipids showed significantly higher (p < 0.01) hydration effects during 3.5 h of application on human skin compared with liposome formulations prepared with soya phospholipids. © 2005 Published by Elsevier B.V. Keywords: Liposomes; Skin barrier; Transepidermal water loss; Skin hydration; Skin aging; In vivo comparison The work was partly presented at the 5th Central European Symposium on Pharmaceutical Technology and Biotechnology in Ljubliana, Slovenia, September 25–27, 2003. Corresponding author. Tel.: +41 61 267 15 01; fax: +41 61 267 15 16. E-mailaddress: hans.leuenberger@unibas.ch (H. Leuenberger). 0378-5173/$ – see front matter © 2005 Published by Elsevier B.V. doi:10.1016/j.ijpharm.2005.02.032