Inhalation Characteristics of Polyanhydride Nanoparticle-Based Pulmonary Delivery Vehicles

Polyanhydrides are biodegradable materials which have been shown to provide sustained delivery of their encapsulated payloads. Copolymers based upon sebacic acid (SA), 1,6-bis-(p-carboxyphenoxy)hexane (CPH), and 1,8-bis-(p-carboxyphenoxy)-3,6-dioxaocatane (CPTEG) have previously been synthesized into nanovaccines and antibiotic delivery vehicles. There are many advantages in developing a dry powder inhalable nanovaccine including: self-administration, improved patient compliance, and elimination of the cold-chain.

In this work we evaluated the incorporation of nanoparticles formulated from two different candidate chemistries, 20:80 CPH:SA and 20:80 CPTEG:CPH, for utilization as a dry powder inhalable nanovaccine. The role of polyanhydride chemistry on nanoparticle primary size, hydrodynamic diameter, and in vitro aerosol deposition were evaluated. Additionally, the incorporation of these formulations into blister packs and dispersion characteristics from a customized dry powder inhaler were investigated. These studies represent the first steps in using polyanhydride nanovaccines and nanoparticle delivery vehicles in a dry powder inhalation system.