Characterize fluticasone propionate (Fp) and combination fluticasone propionate and salmeterol (FS) pharmacokinetic and safety profiles, delivered via a novel, inhalation-driven, multidose dry powder inhaler (MDPI). This multicenter, open-label, four-period crossover, single-dose study randomized patients aged ≥12 years with persistent asthma to Fp MDPI 200 mcg, FS MDPI 200/12.5 mcg, Fp dry powder inhaler (DPI) 500 mcg (250 mcg × 2 inhalations), or FS DPI 500/50 mcg. Blood samples for determination of Fp and salmeterol pharmacokinetic parameters including Cmax, AUC0-t, AUC0-inf, tmax, and t½ were collected predose through 36 h postdose (14 time points). Safety assessments comprised adverse events, vital signs, and physical examinations. The institutional review board approved the study protocol. The pharmacokinetic analysis set and safety population each included 40 patients. Fp systemic exposure (Cmax, AUC0-t, and AUC0-inf) was highest for Fp DPI 500 mcg and similar for Fp MDPI 200 mcg, FS MDPI 200/12.5 mcg, and FS DPI 500/50 mcg. Fp geometric mean t½ values were similar across treatments. Salmeterol Cmax was 20% lower and AUC0-t and AUC0-inf were approximately 50% lower with FS MDPI versus FS DPI. Median tmax and geometric mean t½ were similar between FS MDPI and FS DPI. Adverse events were similar across treatments with no relevant changes in vital signs, physical examinations, or hematology test results. Fp MDPI and FS MDPI produced similar or lower systemic exposure to Fp and salmeterol, despite lower doses, versus conventional DPI devices, suggesting improved efficiency due to formulation and device differences.