Cortisol is a glucocorticoid hormone produced in the adrenal cortex of the human body as a response to stress. Our study focused on hydrocortisone succinate, which has high water solubility, and is used in form of injections and infusions as a vasopressor in the treatment of hemodynamically unstable patients. Since it is extremely unstable in aqueous solutions, it is formulated as a lyophilisate, which is dissolved shortly before use. The aim of the master's thesis was to evaluate the stability of hydrocortisone succinate in solutions for infusion under various storage conditions, which mimic real usage conditions, and to provide evidence based recommendations for its use in hospitals.
Selected literature HPLC-UV methods were tested and the most suitable was additionally optimized in order to achieve stability-indicative method with short run times. The method was evaluated in accordance with the ICH guidelines and confirmed by stress samples. The established method was applied to study the influence of various factors on the stability of hydrocortisone succinate in aqueous solutions, which was quantitatively evaluated by 1st order reaction rate constants. The stability of hydrocortisone succinate was significantly influenced by temperature, which showed very good agreement with the Arrhenius plot. The pH of the solution also had a major influence on stability - it was found most stable at pH between 6 and 7 and least stable in alkaline medium. Its stability in aqueous solutions was lower than in organic solvent, whereas the concentration had no significant effect on its stability.
In the stability study on solutions for infusion, hydrocortisone succinate solutions with concentration of 1 and 4 mg/mL in physiological saline and glucose were prepared, and stored protected and unprotected from light, at room temperature and at 30 °C. We found that even a small change in temperature has an extremely high influence on the decay rate. On the other hand, exposure to light, the solvent, the concentration and the small difference in the pH value did not significantly affect the stability of hydrocortisone succinate. Slightly higher stability was noticed in glucose solution at a concentration of 1 mg/mL, whereas no difference in its stability was observed between the two concentrations in physiological saline. The estimated shelf life (5 % decrease of the active substance), taking into account the confidence interval is between 22 and 26 hours in infusion solutions stored at room temperature and between 5 and 7 hours if stored at 30 °C.
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