Modification/Improvement of the Wurster process for drying or coating sensitive bioactive materials

摘要

The Wurster process is a coating technique that is well suited to uniformly coat or encapsulate individual par-ticulate materials. However, its use for coating sensitive bioactive compounds is often limited because of the potential risks of degradation during operations. In order to avoid a loss of integrity of such material during the process, we proposed some modifications of the equipment. The standard and modified systems were compared using probiotic microorganisms as model for sensitive material. The results obtained for the pressure drop measurements at various air flow rates are rapresented by a 4 distinct states of fluidization for the conventional equipment and only 3 states (SI, S2 and S3) for the modified one. Our results demonstrated that the modifications carried out led to more gentle operating conditions, resulting in an enhanced cell survival during the coating process.