Segregation and Continued Mixing in an Automatic Capsule Filling Machine

Abstract

During test production of an indomethacin 25 mg capsule preparation problems with single-dose variation and variation/reduction in dissolution rate were ascertained. The problems were identified as segregation and overmixing of the powder mixture, which contained magnesium stearate as lubricant. The problems were solved by removing the propeller mixer in the powder hopper and replacing the cylindric powder hopper with a coneshaped hopper, which resulted in mass flow.