Inhalable Antitubercular Therapy Mediated by Locust Bean Gum Microparticles.

Area of Science:

• Pharmacology
• Biomaterials Science
• Infectious Diseases

Background:

• Tuberculosis (TB) is a significant global health challenge requiring novel therapeutic strategies.
• Pulmonary delivery of anti-TB drugs to lung alveoli offers an advantage over oral administration.
• Alveolar macrophages are key hosts for Mycobacterium tuberculosis, making them targets for drug delivery.

Purpose of the Study:

• To develop and characterize locust bean gum (LBG) microparticles for pulmonary delivery of anti-TB drugs.
• To evaluate the potential of LBG microparticles for targeting alveolar macrophages.
• To assess the safety and efficacy of LBG-based drug delivery for tuberculosis therapy.

Main Methods:

• Spray-drying technique was used to produce LBG microparticles incorporating isoniazid or rifabutin.
• Aerodynamic properties of microparticles were assessed for deep lung delivery potential.
• Cytotoxicity was evaluated in lung epithelial (A549) and macrophage (THP-1) cell lines.
• Phagocytosis efficiency by macrophages was quantified.

Main Results:

• LBG microparticles demonstrated high drug association efficiencies (>82%) for isoniazid and rifabutin.
• Microparticles exhibited suitable aerodynamic diameters (1.15–1.67 μm) for alveolar deposition.
• High macrophage phagocytosis rates (>94%) were observed for LBG microparticles.
• Rifabutin-loaded microparticles showed toxicity at high concentrations, considered above in vivo levels.

Conclusions:

• LBG microparticles represent a promising system for pulmonary drug delivery in tuberculosis treatment.
• The system shows potential for enhanced targeting and uptake by macrophages, the primary hosts of M. tuberculosis.
• Further in vivo studies are warranted to confirm the therapeutic potential of this novel delivery approach.