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

Pulmonary tuberculosis (TB) is a worldwide life-threatening infection. Therecommended anti-TB regimen contains oral administration of classical first-line drugs suchas rifampin for 6-24 months which often leads to low patient compliance due to high adverseeffects; therefore, lung localized pulmonary delivery of anti-TB agents may be a suitablealternative. Proliposomes free-flowing powders are well-known carriers for lung delivery sincethey can form liposomes by hydration. Liposomes are safe and useful carriers for lung deliverydue to their phospholipid structure. Porous lactose and mannitol as proliposome carriers were prepared by spray dryingtechnique using sucrose and citric acid as templating agents. Design Expert® software wasused to develop forty formulations based on the porous and non-porous carriers, which werecharacterized with respect to their weight yield, density, and flowability. Rifampin-loadedhydrated liposomes were produced and evaluated for size, morphology, loading capacityand encapsulation efficiency. The optimized proliposomes in vitro release and aerosolizationproperties were evaluated. Solid-state analysis was confirmed by differential scanningcalorimetry (DSC). 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 particlefraction (FPF) of 9.17 ± 0.18% with a fast rifampin release (80%) within one hour. DSC resultsproved that there was no change in the solid-state of rifampin during the production process. Hence, it seems; rifampin loaded inhalable proliposomes may be a suitable systemfor delivering liposomal rifampin into the lungs.