Fig. 5

Bordonein-L stability. a Evaluation of stability after five days at −20 °C and 4 °C and as soon as the lyophilization was finished. The stability was also evaluated for 40 days in the presence of (b) mannitol, (c) sucrose, (d) L-lysine and (e) L-glycine. All samples were kept protected from light. Each point represents the mean ± S.E.M. (n = 3) at each additive concentration (**p < 0.0001 compared to the respective control using one-way ANOVA test). Each bar represents the mean ± S.E.M. (n = 3) at 4 °C, freezing and lyophilization conditions (****p < 0.0001 when 4 °C, freezing and lyophilization was compared to control and when freezing and lyophilization compared to 4 °C using one-way ANOVA test; ♦♦ p < 0.05 when freezing and lyophilization were compared to each other using the t test)