260 0.020 )L 00..001168 /m0.014 µg 0.012 .c ( 0.010 on 0.008 ac 0.006 sm0.004 lP a 0.002 0.000 0 L / Min 5 L / Min 2 L / Min System Flow Fig. 5 Effect of system ﬂow on plasma exposure (PARI LC) variability. This device provided a much better conﬁdence in delivery in a relevant preclinical model in a range which mimics human exposure. Another highly desired advantage is reﬂected in the reduced systemic exposure. The systemic exposure from nanosuspension aerosol delivery is approximately 25% of the IT delivery. This low systemic exposure can provide a potential tool to differentiate top- ical (lung) vs systemic efﬁcacy and side effects. This advantage is particularly important, because a major focus of pulmonary drug development is to improve local exposure/efﬁcacy and minimizing systemic exposure and side effects. The lower systemic exposure observed via nanosuspension aerosol delivery will help researchers fur- ther explore the feasibility to differentiating topical (lung) vs systemic efﬁcacy and side effects pre-clinically. Based on the results from various tests, we concluded that the aerosol delivery of ﬂuticasone nanosuspension is very robust and well suited for pre-clinical pulmonary drug delivery. These novel studies demonstrate that combining nano-suspension and aerosol delivery is a valuable tool for pre-clinical pulmonary drug delivery. The major advanta- ges of this delivery system include the absence of a propellant, ease of production, no solubility limit of the compound, and simulation of actual exposure in humans. Conclusion In pulmonary drug discovery, the ability to evaluate new drugs for efﬁcacy in animal model with quick turnaround and conﬁdence of delivery is very important. 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