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Background: Inhalation of therapeutic aerosols is a long-established means of drug delivery to the lungs or to the systemic circulation. In addition to solutions, suspensions, and particulates, liposomal formulations are being developed for aerosol administration. In this report, we investigated the membrane integrity of liposomes encapsulating the fluorescent model compound, calcein, after nebulization using two novel aerosolization devices, the Aeroneb Pro vibrating-mesh nebulizer (Aerogen, Dangan, Ireland) and the AeroProbe intracorporeal nebulizing catheter (Trudell Medical Corporation, London, Ontario, Canada)., Materials and Methods: The influence of lipid composition and lamellarity on the stability of the vesicles was investigated by measuring changes in median diameter, zeta-potential, and calcein retention., Results: Both nebulizers were able to successfully aerosolise 1.5 mL of liposome suspension in a short period of time. The diameter and zeta-potential of the liposomes was preserved upon nebulization, and the calcein retention was above 70% in all cases., Conclusions: It can, hence, be concluded that both systems, the Aeroneb Pro and the AeroProbe, are well suited for the pulmonary delivery of liposomal formulations, with the AeroProbe having the additional advantage of allowing targeted delivery into the select regions of the lungs with a high degree of efficiency and control.