Potential of dry powder inhalers for tuberculosis therapy: facts, fidelity and future

Tuberculosis (TB) is a contagious and airborne infectious disease caused by the pathogen Mycobacterium tuberculosis (Mtb). In spite of substantial research efforts, continuous multiple high-dose drug therapy regularly for 4-7 months can impede patient quality of life. The pathology of TB and biology of pulmonary airways permits for a variety of drug delivery strategies and natural route of infection denotes a more logical remedial approach for treatment of TB. Pulmonary delivery is non-invasive, allow easy transcytosis in alveolar region, avoids first-pass metabolism and extensive vascularization facilitates delivery of therapeutic agents to infection site. It also potentially reduces the frequency with dose requirement and linked side effects. Dry powder is a most preferred inhalation option due to their greater physiochemical stability over liquid or suspension based formulations. Dry powder inhalers (DPIs) are easy to handle and appropriate for high-dose formulations. Moreover, the progress of disciplines such as nanotechnology, particle engineering, material science and molecular biology permits further expansion of treatment capability and efficiency. Thus, this article will focus on the role of novel DPIs systems for treatment of TB. This article also contains a dedicated section discussing about technical limitations and clinical challenges with help of strengths, weaknesses, opportunities and threats (SWOT) analysis. Additionally, it will also offer some basic background information for drug repurposing, formulation development and drug delivery systems.