Abstract

Extended-release inhalable drug products are highly desirable in aerosol science due to the need for multiple dosing when treating chronic diseases such as asthma and chronic obstructive pulmonary disease (COPD). Gelatin is a biodegradable polymer used for controlled-release formulations and accepted by the US Food and Drug Administration (FDA) at high doses in the lung (100 mg daily) [1]. Gelatin has been studied as a carrier to control the release of active pharmaceutical ingredients (APIs), modulating the release profile of drugs by diffusion. The following study proposes a platform that uses ionotropic interaction between anionic drugs and a positively charged gelatin to reduce its release rate. As a secondary strategy, the microcapsules were coated with different fatty acids to modulate their diffusion rate. The inhalable microcapsules were produced via spray drying in a single step using a two or three-fluid nozzle, depending on whether the microcapsules were coated. In addition, the inhalable formulations were evaluated for aerodynamic behavior and in vitro dissolution profiles to evaluate the combined controlled release strategies.