Validação de metodologia analítica para a determinação de benzofenona-3 nanoencapsulada incorporada em creme gel e estudo da estabilidade físico química

Abstract

The aim of this research was to develop and validate an ultraviolet spectrophotometric method for the quantitative analysis of the content of benzophenone-3 (BZ3) nanoencapsulated and incorporated in gel cream and to carry out a study of its stability and determine its shelf life. The validated method was selective and linear in the range 2–20 μg/mL, with a correlation coefficient of (r) of 0.999996, precise (relative SD < 2.44%), exact (98.8% - 100.3%) and robust. It can, therefore be used in the analysis of nanoencapsulated BZ3 gel cream. Gel creams containing nanoencapsulated and free BZ3 showed no significant alterations in appearance, colour, smell, pH, viscosity or spreadability, within the 180 day period during which they were exposed to a controlled temperature of 40 ºC and relative humidity of 75%. In both formulations, the BZ3 content fell, but in the free form it was degraded more quickly (30 days) than in the nanoencapsulated form (150 days). This indicates that the nanocapsules protected the active ingredient. For the gel cream containing the BZ3 nanocapsules, the estimated shelf life was 125 days, and for the free BZ3, 69 days.