Introduction. Under galenic perspective O/W emulsion formulation is a fundamental issue not only for the potential problems they offer being thermodynamically unstable systems, but also for the increasing interest on the use of this particular class of formulations. In fact humectants and moisturising agents are normally incorporated to re-establish or to help to maintain Stratum corneum (SC) emoliency and its global rheological properties. Apart from the ability of the emulsifying agent to assist in the emulsion stabilisation, specially to avoid globular coalescence, it is often considered advantageous to use combinations of macromolecules such as polymers, to increase viscosity, although one should always ensure the overall stability of the formulation both in physical-chemical and in microbial terms. In the present work, the authors tested the incorporation of polymers traditionally used in hair-care products which showed a particular affinity to keratin, in O/W skin care creams and compared its stability to other standard emulsions. A biological preview on the effects detected on SC hydration was also approached in order to establish the eventual advantages of such procedure.Material and Methods. Four emulsions were prepared containing: Eumulgin B1 3%,Cetyl alcohol 15%, Cetiol V 6%, Propilenglycol 3%, Preservative 1%, Polymer aq.sol.10% and desionised water q.b. 100%. Previous to formulation, 3 different polymers (Merquat 550,Gafquat 755 and Acacia) were added to an appropriate amount of water in order to form gels containing the same dried weigh. Physical and chemical stability was assessed through centrifugation, ''ageing'' (at different temperatures), as well as the evaluation of pH and water content. Microbiological stability was achieved through ''challenge tests''. Biological effects of the present formulations were assessed in human volunteers through non-invasive technology. Following a previously designed protocol, Trans-epidermal Water Loss (TEWL), Epidermal ''Capacitance'' changes and skin surface pH were evaluated through standard technologies (C+K electronics GmbH). Descriptive statistics and Student's t Test was also performed.Results and Conclusions. Both stability studies (physical-chemical and microbiological) suggest that there are no significant differences among several batches for each tested formulation. Concerning biological effects, under the present experimental conditions, no significant differences were found, specially above 100min duration time. However, being preliminary results, complementary studies including the methodological refinements, must be performed in order to establish a complete screening of water kinetics changes induced from the formulation on epidermal surface.