Particle engineering in dry powders for inhalation

Abstract

Drug administration by inhalation is a well-established approach to treat respiratory and systemic diseases. To deliver a drug into the lung dry powder inhalation (DPI) is an advantageous, but yet challenging option. A variety of strategies is available for developing DPI formulations. These formulation strategies should address the present disadvantage of insufficient drug delivery and enable therapies in general or to reach new targets (e.g. mucosal vaccination). To increase therapy safety and efficacy scientists challenge the limits of technical feasibility to engineer respiratory medicines. In this review, we provide a concise overview of particle engineering as enabling formulation technique or as an optimisation approach for existing strategies in pulmonary drug delivery. It comprehensively describes different techniques for particle engineering in carrier-based blends for inhalation. This covers considerations on which attributes are beneficial for carriers, followed by methods to modify such attributes or directly manufacture the desired carriers. Furthermore, this work comprises the current state of knowledge on nanocrystal and nanoparticle production as well as other carrier-free technologies and their applications. This review is completed by a glance in the future of carrier engineering using additive manufacturing.

Keywords: Pulmonary drug delivery; additive manufacturing; carrier engineering; microparticles; nanocrystals; nanoparticles.