Evaluation of supercritical fluid engineered budesonide powder for respiratory delivery using nebulisers

Objectives:

Currently, suspensions prepared from micronised drug substances are the only delivery system marketed for nebulisation of steroids, and reported inconsistent or low bioavailability arising from their use provides a rationale for researching alternative formulations. Supercritical fluid processing of drug substances to obtain respirable-sized particles has been used over the last decade to formulate dry powder inhalers. We aimed thus to process budesonide powder to improve its deposition characteristics.

Methods:

In an attempt to overcome the limitations of nebuliser suspensions when prepared from micronised drug particles, budesonide powder was processed using a supercritical fluid based process and suspended using Tween 80 as a surfactant to provide an aqueous nebuliser formulation. The in-vitro characteristics of the emitted dose on nebulisation for the prepared suspension were then compared to a commercially available suspension formulation of budesonide using a jet and a vibrating mesh nebuliser.

Key findings:

The results showed a significant improvement of the in-vitro deposition properties of the suspension containing supercritical fluid engineered budesonide particles.

Conclusions:

The results indicated the benefit of such materials compared with traditionally micronised drug powders.