PRELIMINAR EVALUATION OF STABILITY OF NON-IONIC EMULSION CONTAINING KOJIC ACID 2.0% FROM COMPOUNDING PHARMACIES

Abstract

Emulsions containing kojic acid are common to be used in skin whitening treatments. In this work, it was evaluated the preliminary stability of non-ionic lotions containing 2.0 % kojic acid produced in compounding pharmacies. The products were acquired from four compounding pharmacies in Porto Alegre city. The samples, in polyethylene flasks, were submitted to storage at 25 and 45ºC and analyzed at periods of zero, 7, 15, 30 and 60 days. The samples were evaluated in order to determine the organoleptic characteristics, pH, centrifugation test and weight of storage flasks.
The organoleptic profile was modified after 7 days of storage for samples at 45 ºC. For pH, samples at 45 ºC presented a reduction in the values, with an increase in acidity at the time. In this case, the sample centrifugation did not influence in this parameter, neither led to phase separation. For weight determination, the results demonstrated a modification in the samples stored at 45 ºC, which illustrate the importance to have attention for storage material. The proposed assays emphasize the importance of stability studies of cosmetic products containing kojic acid, mainly  considering the formulation and the product storage conditions.