Dry powder inhalation systems for pulmonary delivery of therapeutic peptides and proteins

Abstract

Background: Dry powder inhaler (DPI) systems are widely accepted as an alternative to injection and oral administration of therapeutic peptides and proteins. In contrast to oral therapy, pulmonary administration eliminates the potential for poor absorption and high metabolism in the gastrointestinal tract and it also evades first-pass effects in the liver. Inhalation therapy does not cause pain, unlike injection therapy, and this reduces the strain on the patient, possibly leading to improved treatment outcomes. Objective: Alongside the expansion of the DPI market, the science and engineering of dry powder formulations and devices have also grown. In this review, we present information regarding some recent advances in this expanding field, with emphasis on pulmonary delivery of therapeutic peptides and proteins. Methods: The scope of this review was defined by patent information on DPI devices, formulations and pulmonary delivery of therapeutic peptides and proteins for topical and systemic administration. Patent and bibliographic searches were carried out using various databases and websites, including CAplus, United States Patent and Trademark Office patent full-text and image database, Industrial Property Digital Library, Esp@cenet, World Intellectual Property Organization patentscope, Freepatentsonline, and PubMed database. Results/conclusion: A number of research efforts have demonstrated the feasibility of pulmonary delivery systems for therapeutic peptides and proteins, employing novel inhaler devices, powder engineering technologies, functional drug carriers and absorption enhancers. Optimized drug delivery would be achieved not only by improving relatively simple inhaler devices but also by more sophisticated formulations that disperse easily in the air stream.