Sterility and stability testing of preservative-free albuterol

BACKGROUND Continuous albuterol administration (CAA) is commonly used in hospitalized patients for treatment of asthma exacerbations. Due to higher dose requirements, CAA requires large volumes of albuterol obtained from multidose vials containing benzalkonium chloride (BAC). BAC is a common pharmaceutical preservative and potent bronchoconstrictor, which may antagonize the bronchodilation effects of albuterol. Some institutions are using preservative-free (PF) albuterol for their CAA. However, no published data currently exist to support the extended sterility or stability of this formulation. OBJECTIVE To evaluate the sterility and stability of PF-albuterol. METHODS Sterility testing was conducted for PF- and BAC-albuterol when stored at room temperature. Samples were incubated for 10 days in aerobic and anaerobic blood culture media to assess for bacterial growth. Stability of both albuterol formulations at high (0.67 mg/mL) and low (0.17 mg/mL) concentrations was determined at room temperature and under refrigeration. High performance liquid chromatography was used to evaluate samples up to 168 hours after preparation. RESULTS No bacterial growth was witnessed from either albuterol formulation at day 10 of observation. Both high and low concentrations of PF-albuterol and BAC-albuterol were stable at room temperature for up to 168 hours. There were no differences in stability between storage conditions for any formulation. CONCLUSIONS Under the current study conditions, there was no difference in sterility or stability for PFalbuterol when compared with BAC-albuterol. Thus, based on the findings of this study, PF-albuterol is sterile and stable up to 168 hours when stored at room temperature or under refrigerated conditions. The findings of this study do not confirm the therapeutic efficacy of PF-albuterol compared with BAC-albuterol for the treatment of asthma exacerbations. Further studies are warranted to determine the efficacy of PFalbuterol verses BAC-albuterol when used for CAA.