Microbiological and Physicochemical Stability of Fentanyl and Sufentanil Solutions for Patient-Controlled Delivery Systems

The aim of this study was to assess the microbiological and physicochemical stability of opioid solutions containing fentanyl or sufentanil and thereby determine the feasibility of extending the expiration dates after mixing. Five systems containing fentanyl or sufentanil solutions at 50 μg/mL in portable patient-controlled analgesia (PCA) systems were filled and stored at room temperature for 14 days. They were sampled immediately after preparation, at day 3, and each day of the following weeks. Microbiological stability was assessed by performing sterility tests. The physicochemical study was performed by determining aspect, pH, and osmolality evolution. All samples were tested for appearance, change in color, and loss of concentration using an analytical method. There was no significant change in pH and osmolality values of any solutions. No precipitation or change in color was observed in any of the sample solutions. There was no significant loss of fentanyl or sufentanil over 14 days (4.3% and 4.1%, respectively). This study indicates that both drug solutions in the PCA systems are stable for a minimum of 14 days at room temperature.