Capreomycin inhalable powders prepared with an innovative spray-drying technique

Area of Science:

• Pharmaceutical Technology
• Drug Delivery Systems
• Materials Science

Background:

• Inhalable drug delivery offers targeted treatment for respiratory diseases.
• Developing stable and respirable drug powders is crucial for effective inhalation therapy.
• Capreomycin is an important antibiotic for treating multidrug-resistant tuberculosis.

Purpose of the Study:

• To produce inhalable capreomycin sulfate powders using a novel spray-drying technology.
• To optimize the spray-drying process for desirable powder characteristics like size, morphology, flowability, and aerodynamic properties.
• To evaluate the potential of nano spray-drying for producing respirable capreomycin sulfate formulations.

Main Methods:

• A 2(3) factorial design was employed to identify optimal spray-drying parameters.
• Powders were characterized for particle size (mean volume diameter, dv), span, yield, morphology, flowability, and aerodynamic properties.
• Mathematical models were used to assess process predictivity.
• Optimization was performed using bacitracin as a model drug, followed by capreomycin sulfate processing.

Main Results:

• Optimal conditions for spray-drying were determined, achieving high desirability based on small particle size and high yield.
• Mathematical models demonstrated good predictivity (biases < 20%).
• Initial processing of capreomycin sulfate yielded inhalable powder (yield 82%, dv 3.83 μm, span 1.04). Further optimization improved characteristics (yield ~71%, dv 3.25 μm, span 0.95).
• Formulated capreomycin sulfate powders achieved high emitted dose (87%) and respirable fraction (~27%).

Conclusions:

• Novel nano spray-drying technology can successfully produce inhalable capreomycin sulfate powders.
• Optimized process parameters are critical for achieving desired aerodynamic properties for inhalation.
• The developed capreomycin sulfate powders demonstrate significant potential for effective pulmonary drug delivery in tuberculosis treatment.