The effect of process variables on the degradation and physical properties of spray dried insulin intended for inhalation.

The aim of this study was to investigate the effect of process variables on the degradation and physical properties of spray dried insulin intended for inhalation. A 2(4) full factorial experimentally designed study was performed to investigate the influence of the following independent spray drying variables: feed flow rate, nozzle gas flow rate, inlet air temperature and aspirator capacity (drying gas flow rate). Human insulin (biosynthetic and Ph.