Thomas Brinz

Preparation and Measurement of Combinatorial Screen Printed Libraries for the Electrochemical Analysis of Liquids

A combinatorial approach to the development of new screen printing pastes is introduced. We used a novel technique for printing electrodes out of different binary mixtures of pastes. The pastes applied are based on the transition metals iridium and ruthenium in the form of their (IV) oxides. Using multielectrode arrays,these pastes were printed on the same substrate in one single step. In this work, pH sensors were printed based on a concept using solid state electrodes both with the measurement and the reference electrode.After the sintering process, the pastes were then evaluated using a robotic setup designed to handle the high impedances characteristic for pH sensors as well as to automatically manipulate the fluids in contact with the sensors.

Automation of a dosing-disc capsule filler from the perspective of reliability and safety

Abstract The aim of this paper is to explore the possibility to develop an automatically adjustable, reliable, and safe capsule filling operation. Process parameters that are critical for the tamping pin process were reviewed based on the literature and via experiment. Dosing disc height, powder bed height, machine speed, pressure on the tamping pin, and immersion depth were reviewed. Two investigations were performed on a GKF 702. In the first one, the powder feed rate onto the dosing disc was examined and modified. A distance sensor with a PID controller enabled a constant powder bed level with an online changeable set point. For a bad flowing product an improvement of the fill weight variation could be achieved by automatically adjusting the feed rate to the correct speed and matching the actual process conditions of the capsule filler. The second part of the study concerned the safety of the filler operation. Introducing a force transducer on the transfer station is a promising option for running the capsule filler safely within its process specifications. The tamping pin pressure was used to provoke different transfer forces. A deviation from a defined process specification led to a safe stop of the machine. In summary, the automated adjustment of several critical process parameters appears to be feasible and supports the rational development of efficient production processes using a dosing disc capsule filler. This is especially relevant for continuous production of pharmaceuticals.

Rapid automated process development of a continuous capsule-filling process

Graphical abstract Figure. No Caption available. &NA; This paper introduces a rapid automated process‐development approach for a continuous capsule‐filling process. In our proposed method, both the material attributes and the critical process parameters were varied to understand and to optimize the overall process. Using our approach a statistical process model can be generated with unprecedented speed (2 days), which is the prerequisite for effectively developing and operating continuous process platforms. In a first set of experiments a process model was developed using different mixture compositions of ascorbic acid, lactose and magnesium stearate while changing simultaneously the critical process parameters of the capsule filler (speed, pressure, immersion depth and powder bed height). Targets of the model were the mean fill weight and the relative standard deviation of the produced capsules. In a second experimental set the model was tested, i.e., the goal was to predict the behavior of the system at different set points in order to predict weight and relative standard deviation for predefined targets. Predictions were very good, thus validating our approach. The combination of the rapid automated process development approach and the continuous capsule‐filling process resulted in a new strategy for the development and manufacture of pharmaceutical dosage forms.