Preparation of budesonide sustained-release dry powder for inhalation and influence of lactose content

Using high pressure homogenization method combined with spray-drying, budesonide-loaded chitosan microparticles were prepared and the in vitro release profile was investigated. The microparticles were then blended with lactose using a vortex mixer, influence of mixing speed, mixing time on drug recovery rate and content homogeneity were investigated. Meanwhile, influence of lactose content on drug recovery rate, content homogeneity, powder flowability and in vitro deposition were studied. It turned out that budesonide was released from the microparicles in a sustained manner, with fine particle fraction as high as 46.0%, but the powder flowability was poor. After blending with 10 times of lactose, the drug recovery rate was 96.5%, with relative standard deviation of drug content 2.5%, and fine particle fraction of the formulation increased to 59.6% with good flowability. It's demonstrated that using a vortex mixer, budesonide sustained-release dry powder for inhalation with good recovery and content homogeneity could be prepared, the formulation had good flowability and was suitable for pulmonary inhaling.