Dry Powder Inhalation

  The Aim of this study was preparation of dry powder formulation of rifampicin loaded polymeric microparticles as dry powder formulation for inhalation in effective tuberculosis treatment.The microparticles containing rifampicin (RIF) were prepared by spray drying method using different biocompatible polymers like chitosan and hydroxyl propyl methyl cellulose (HPMC) The microparticles and microparticle blend with coarse carrier Inhalac 230 were investigated for its aerosolization properties like emitted dose, Mass median aerodynamic diameter, Fine particle Fraction, Geometric Standard Deviation.The spray drying method produced wrinkle surfaced porous microparticles under the size range of 10µm. Mass median aerodynamic diameter obtained for all formulation ranged in 2.68 µm to 3.73 µm and Fine particle fraction in between 51.58 ± 5.36 to 72.74 ± 3.18. The lowest tapped density value obtained was 0.102 g/cm2 belong to formulation coded M1. In vitro deposition studies using cascade impactor showed emitted dose of > 90% for all batches. The polymeric microparticles produced by spray drying technique showed promising particle characteristics suitable for inhalation with Fine particle fraction (72.74 ± 3.18) of total emitted dose, after blending with lactose. The blending of the microparticles with Inhalac 230 allowed the Fine particle fraction values to increase by increasing the dispersibility of powder on inspiration. Key words: Rifampicin, Dry Powder Inhalation, Chitosan, HPMC, Interactive blend.