Injectable-drug formulations for both subcutaneous and intravenous administration are designed to be consistent with the number of solutes present in human tissue. Such consistency with physiological conditions is achieved by adding an appropriate amount of salt and/or sugar to attain the desired tonicity. Care must be taken to prevent exposure of cells to either hypotonic or hypertonic formulations that could cause lysis or shrinking, respectively (1). Injection of formulations that deviate from human-plasma osmolality (295 mOsm) can cause pain upon…