Inhalable Spray Dried Pro-Liposome Powder Containing Budesonide for Pulmonary Delivery

Budesonide is an anti-asthmatic agent which is used to control the symptoms of asthma like bronchospasm, oedema. Drug delivered to lung through inhalation will provide systemic and local drug delivery at lower dose in chronic and acute diseases. Dry powder inhalers are the best choice for targeting the anti-asthmatic drugs through pulmonary route. The objective of the present study is to prepare inhalable lipid coated budesonide microparticles by spray drying method so effective delivery of budesonide to the lungs can be achieved. The microparticles in the form of dry powder were obtained by either spray drying liposomal drug suspension or lipid drug suspension. The liposomes were initially prepared by solvent evaporation method using Hydrogenated Soyabean Phosphatidylcholine and Cholesterol (1:1, 1:2, 2:1) as lipid carrier and then spray dried later with mannitol as bulking agent at different lipid to diluent ratio (1:1.25, 1:2.5 & 1:5). The liposomes and liposomal dry powder were evaluated for vesicle size, % entrapment efficiency, in vitro drug release studies, powder characteristics, aerosol performance and stability studies. The liposomes prepared showed vesicle size (2-8 µm), Entrapment efficiency (92.22%) at lipid: drug ratio of (2.5:1) and observed 80.41 % drug release in 24 hrs. Pro-liposomes prepared by spray drying of liposomal drug suspension (LSD1) showed emitted dose, mean mass aerodynamic diameter, geometric standard deviation and fine particle fraction of 99.01%, 3.12 µm, 1.78 and 43.5% along with good powder properties. The spray dried powder was found to be stable at 4 ± 2 °C & 65% ± 5 % RH. The inhalable microparticles containing Budesonide containing lipid dry powder was successfully prepared by spray drying method that showed good aerodynamic properties and stability with mannitol as diluent. The microparticles produced with this novel approach could deliver drug on target via inhalation route and also ease manufacture process at large scale in fewer production steps.