Estabilidade preliminar de formas magistrais contendo hidroquinona.

Abstract

Hydroquinone is the most depigmenting agent used for the treatment of hipermelanoses. It is an asset widely manipulated in compound pharmacies, but it has the inconvenience of chemical instability, being easily oxidized. This work aimed to carry out the study a primary stability during a period of thirty days using masterly cream and gel forms with hydroquinone, analyzing the content and physicochemical parameters of the samples before (t0) and after (t30) frostdefrost cycle. The methodologies used for the evaluation of the preliminary stability submitted to frost-defrost cycles (5ºC ± 3ºC and 25ºC ± 2ºC) were: macro- and microscopic aspect, viscosity, pH, centrifugation test and the Hydroquinone content by the titration method. The results showed that macro and microscopic aspects have did not changed during the test. At t0, most formulations containing hydroquinone showed a reduction in pH compared to placebo. Comparing Formulação Alquimia Creme (FAC) and Formulação Alquimia Gel (FAG) in relation to the t0 t30 clearly observed, a decrease in the pH values obtained. However, only FAG formulation showed significant difference (p <0.05). All formulations had a reduction in viscosity over time, but no significant difference (p> 0.05). In the t30, all the samples presented increase in the spreadability in relation to the t0 (p> 0.05). The hydroquinone content decreased in all formulations after the storage conditions evaluated, but remained within the pharmacopoeic recommendation (94-106%). Finally, the mentioned work indicated the importance of the study of preliminary stability of compound forms, being possible to conclude that the formulations presented variations of pH and spreadability when submitted to extreme conditions of temperature. Such alterations did not compromise the organoleptic characteristics and content of the same ones, being possible to make use of buffering agents for the correction of the pH, thus, increasing the stability of the formulations.