Bioequivalence of fluticasone propionate and salmeterol (FS) given by the FS Spiromax® and Seretide Accuhaler® systems .

Objective: To determine pharmacokinetic (PK) profiles of fluticasone propionate (FP) and salmeterol (SAL) in healthy volunteers following administration as two inhalations from the FS Spiromax 500/50 µg and Seretide Accuhaler 50/500 µg inhalers, without (study 1, n = 79) and with charcoal block (study 2, n = 77). Safety was also assessed.

Materials And Methods: In two single-center, open-label, randomized two-period crossover studies, PK parameters were calculated from plasma drug concentrations obtained pre-dose through 36 hours post-dose. Bioequivalence was established if the 90% confidence intervals for the geometric mean ratios of the area under the plasma drug concentration-time curve from time zero to the time of the last quantifiable concentration (AUC) and the maximum observed plasma concentration (C) for the comparison of both FP and SAL were within 0.80 - 1.25.

Results: In study 1, in subjects administered FS Spiromax, the mean (standard deviation (SD)) FP AUC and C were 1,622.64 (419.44) pg×h/mL and 151.36 (40.37) pg/mL, respectively, vs. 1,487.52 (341.25) pg×h/mL and 137.57 (33.64) pg/mL with Seretide Accuhaler. Mean (SD) SAL AUC and C with FS Spiromax were 408.42 (155.40) pg×h/mL and 269.48 (105.74) pg/mL, respectively, vs. 401.79 (125.32) pg×h/mL and 265.66 (87.28) pg/mL with Seretide Accuhaler. Comparable data were seen in study 2 with charcoal block. Bioequivalence of FS Spiromax with Seretide Accuhaler was observed both without and with charcoal block for FP and SAL for both AUC and C. Both study treatments were well tolerated, with a similar incidence of adverse events reported with the single use of FS Spiromax (23% study 1, 16% study 2) and Seretide Accuhaler (22%, 15%).

Conclusion: FS Spiromax 500/50 µg (± charcoal block) was bioequivalent to Seretide Accuhaler 50/500µg.
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