Spray drying TB vaccines for pulmonary administration.

Background: New developments in materials science provide innovative technologies that allow mucosal immunization against tuberculosis. Recent studies report that spray-drying Mycobacterium bovis Bacillus Calmette-Guérin (BCG) allows efficient aerosol delivery of TB vaccines to the lung.

Objectives: To consider powder formulation of BCG for inhalation by spray-drying and its potential application to other vaccines given the unique challenges in the process, formulation and delivery.

Methods: Description of current advances in spray-drying and aerosol delivery, and its application to preparation of BCG TB vaccine for inhalation. Special consideration is given to physical properties, viability, stability and delivery aspects.

Results/conclusion: Spray-drying generates powders with excellent dispersion qualities suitable for targeted delivery to the deep lung. TB vaccine for inhalation prepared by spray-drying is feasible, low-cost and pharmaceutically scaleable.