An expert opinion on respiratory delivery of high dose powders for lung infections

ABSTRACT

Introduction

High dose powder inhalation is evolving as an important approach to to treat lung infections. It is important to its identify applications, consider the factors affecting high dose powder delivery, and assess the effect of high dose drugs in patients.

Area covered

Both current and pipeline high dose inhalers and their applications have been summarized. Challenges and opportunities to high dose delivery have been highlighted after reviewing formulation techniques in the context of factors affecting aerosolization, devices, and patient factors.

Expert opinion

High dose inhaled delivery of antimicrobials is an innovative way to increase treatment efficacy of respiratory infections, tackle drug resistance, and the scarcity of new antimicrobials. The high dose inhaled technology also has potential for systemic action; however, innovations in formulation strategies and devices are required to realize its full potential. Advances in formulation strategies include the use of excipients or the engineering of particles to decrease the cohesive property of microparticles and their packing density. Similarly, selection of a synergistic drug instead of an excipient can be considered to increase aerosolization and stability. Device development focused on improving dispersion and loading capacity is also important, and modification of existing devices for high dose delivery can also be considered.

KEYWORDS:

• Antibiotics
• dry powder inhalers
• inhalation
• powder formulation

Article highlights

• A review on reformulating drugs, particularly antimicrobials, as inhalable dry powder

• Evaluation of current and potential techniques to prepare high dose dry powder including milling, crystallization, thin film freeze drying, spray drying, and spray freeze drying.

• A description of excipients used to improve the aerosolization of high dose dry powder.

• Meeting the challenges faced in developing high dose powders for inhalation: preparative techniques, safe new excipients, high payload capacity devices, and local side effects.

This box summarizes key points contained in the article.

Declaration of interest

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Additional information

Funding

This paper was funded by The University of Otago Research Grants.