Carrier Effect in Development of Rifampin Loaded Proliposome for Pulmonary Delivery: A Quality by Design Study

Purpose: Pulmonary tuberculosis (TB) is a worldwide life-threatening infection. The recommended anti-TB regimen contains oral administration of classical first-line drugs such as rifampin for 6-24 months which often leads to low patient compliance due to high adverse effects; therefore, lung localized pulmonary delivery of anti-TB agents may be a suitable alternative. Proliposomes free-flowing powders are well known carriers for lung delivery since they can form liposomes by hydration. Liposomes are safe and useful carriers for lung delivery due to their phospholipid structure. Methods: Porous lactose and mannitol as proliposome carriers were prepared by spray drying technique using sucrose and citric acid as templating agents. Design Expert® software was used to develop forty formulations based on the porous and non-porous carriers, which were characterized with respect to their weight yield, density, and flowability. Rifampin-loaded hydrated liposomes were produced and evaluated for size, morphology, loading capacity and encapsulation efficiency. The optimized proliposomes in vitro release and aerosolization properties were evaluated. Solid-state analysis was confirmed by differential scanning calorimetry (DSC). Results: Porous lactose surface area was 80 folds higher than non-porous one, respectively. Optimized porous-based proliposome indicated the acceptable aerosolization properties, including mass median aerodynamic diameter (MMAD) of 6.21 ± 0.36 μm and fine particle fraction (FPF) of 9.17 ± 0.18% with a fast rifampin release (80%) within one hour. DSC results proved that there was no change in the solid-state of rifampin during the production process. Conclusion: Hence, it seems; rifampin loaded inhalable proliposomes may be a suitable system for delivering liposomal rifampin into the lungs.