A modified signal analysis system for end-point control during granulation

Abstract A signal analysis system with memory-programmable automatic process control for determining power consumption in a high-shear mixer is described. A measuring transformer for unbalanced loads and special cascade transformers with controllable amplification stages allows highly accurate measurements to be made. The signal analyis system makes it possible to perform gliding mean value calculations of the measuring signal and to evaluate the signal fluctuations. The granulation end point is determined by curve analysis. Using this system, granules with a reproducible particle size distribution are obtained from active ingredient/excipient mixtures which either show a tendency to form lumps in the case of overwetting (paracetamol) or require a short granulation time due to low melting points (ibuprofen). The software, which allows the flexible setting of several system parameters, permits optimal adjustment to the behaviour of specific products.