J. Cosmet. Sci., 60, 627–636 (November/December 2009) 627 Study and description of hydrogels and organogels as vehicles for cosmetic active ingredients M. E. MORALES, V. GALLARDO, B. CLARÉS, M. B. GARCÍA, and M. A. RUIZ, Pharmacy and Pharmaceutical Technology Department, School of Pharmacy, University of Granada, 18071 Granada, Spain. Accepted for publication April 1, 2009. Synopsis Cellulite, a clinical syndrome mainly affecting women, involves specifi c changes in conjunctive dermic and subcutaneous tissue, leading to vascular and hypertrophic alterations in adipose tissues and the consequent alteration of tissue structure. This paper describes the design of hydrogels and pluronic-lecithin organogels elaborated as vehicles of Aloe vera (Aloe vera linné) and Hydrocotyle asiatica (Centella asiatica) for the treatment of cellulite. The objective of this work was to carry out a complete evaluation of the proposed formulae through the study of the organoleptic and rheological properties of the formulae. Our work revealed that, in appearance, hydrogels show better organoleptic characteristics than organogels. On the other hand, from a rheological point of view, both hydrogels and organogels display a plastic behavior. However, the main dif- ference between the two is that the more complex internal structure of the organogel bestows it with more viscosity. Finally, in vitro tests with Franz-type diffusion cells revealed that the release of cosmetic active principle from the tested excipients was appropriate, both in terms of magnitude and velocity. INTRODUCTION Cellulite, a clinical syndrome mainly affecting women, involves specifi c changes in con- junctive dermic and subcutaneous tissue, leading to vascular and hypertrophic alterations in adipose tissues and a consequent alteration of tissue structure (1,2). Hence, in order for a specifi c treatment to be effective, it is important that the formula should be capable of acting upon the three components of cellulite: microcirculation, fatty tissue, and connec- tive tissue (3). The products used for the treatment of cellulite are based on a variety of phytotherapeutic extracts and other active substances, whose mission is to increase the excretion of urine (diuresis), to stimulate endocrinal function, to facilitate the liver me- tabolism of fats, and to aid circulation (4). In this study, two widely used anti-cellulite active principles, Aloe gel side 10:1 and a glycolic extract of Hydrocotyle asiatica, were incorporated into topical pharmaceutical formulations, with the objective of reaching the coetaneous layers where their anticellulitic action is most effective. As an anticellulitic treatment, Aloe gel aids tissue and cellular regeneration of the treated area (5) because of Address all correspondence to M. A. Ruiz.