A Novel Approach for the In-Vitro Drug Release Testing of Metered Dose Inhalers
Dissolution of inhalers have been previously tested in typical dissolution apparatus on un-fractioned powders and particles collected from the metered dose inhaler. In this study, full fine particle fractions (FPF) were collected with the use of a modified Anderson cascade impactor (ACI). The products consisting of the FPF were collected with the USP Cascade impactor with a polytetrafluoroethylene funnel (TF) a small collection plate (CP) modification. The fractions were mounted in an Agilent Enhancer Cell which conformed to USP <1724> Immersion Diffusion Cell - Model A and placed within the 200 mL vessel containing 50 mL of Gamble’s solution with 0.2% v/v Tween 80. The resulting dissolution profiles showed burst release of salbutamol sulfate while demonstrating a sustained release profile of fluticasone. The study performed at the National University of Singapore demonstrated a reproducible method which may be used for evaluation of the full FPF of orally inhaled products.