RIFAMPICIN LOADED SPRAY-DRIED OLIBANUM GUM RESIN PULMOSPHERES FOR LUNG DELIVERY

Pulmospheres of Rifampicin were prepared successfully with cyclodextrin using olibanum gum resin as a rate controlling biodegradable natural polymer by novel spray drying technique. Hydroxypropyl-β-cyclodextrin was used as solubilising agent to enhance the solubility and permeation of poorly soluble rifampicin. The physcochemical characteristics of   rifampicin loaded pulmospheres were evaluated for mean particle size, thermal behaviour and surface morphology. The mean particle size for optimized formulation F1 was found to be 3.5 µm and spray-dried pure rifampicin also showed same value. Scanning Electron Microphotographs of pure drug has shown a typical and regular size indicated crystalline nature, whereas, spray dried pure drug and formulation F1 have shown spherical particles with porous surface indicated the conversion of crystalline drug into amorphous form. Rifampicin loaded spray-dried pulmospheres using olibanum gum resin showed drug release up to 72 hours. The release of rifampicin was greater in simulated physiological fluid of pH 7.4 which was 94 % as compared to simulated lung fluid of pH 5.2 at the end of 72 hours. Rifampicin loaded spray-dried microspheres were proposed for pulmonary drug delivery.   Keywords: Rifampicin, Lung targeting, Olibanum gum resin, Spray-drying, Pulmosphere