2023 de Ponga Fluidized Bed Co-Melt Granulation New Insights in the Influence of Process Variables and Validation of Regime Map Theory
The understanding of granule growth mechanisms and the effects of formulation and operating conditions over product quality and process performance in ﬂuidized bed co-melt granulation is nowadays of great interest. In this sense, this work systematically studies the combined effects of binder content (WPEG ) and ﬂuidization air ﬂowrate (FA ) and temperature (TA ) on granules’ quality and process-related variables (product mass (MP ), elutriated ﬁnes (Mf ), mass stuck on walls (MW )) by using a Box–Behnken-type design of experiments (DoE), as it is a statistical tool suggested by the Quality by Design (QbD) initiative. It was found that the granules’ size and powder ﬂowability are signiﬁcantly affected by WPEG (higher WPEG , higher granule size and better ﬂowability). Interestingly, TA is the process variable that signiﬁcantly affects MP , enhancing process performance at high temperature values. Regarding FA , it signiﬁcantly affects d10 , promoting the formation of small particles due to breakage at high ﬂowrates and the presence of non-elutriated powder at low ﬂowrates. As a consequence, intermediate FA is the optimum for obtaining higher MP . Regarding regime map studies, most runs experienced a rapid growth regime, which is in accordance with the granules’ high pore saturation. This result agrees with the observed high increment in particle size and the morphology of the ﬁnal granules, allowing researchers to validate and extend existing previous maps.