Process Refractometry - Everything from Physical Basics to Innovative Solutions for the Food and Pharmaceutical Industries

Process measuring instruments are essential tools for monitoring and controlling critical process parameters. Risk analysis identifies critical process parameters which must be monitored and controlled during the production process in order to achieve a specified product quality. Depending on how important a process step is, comprehensive monitoring and control are essential in order to ensure that the process parameters continue to meet specifications.

Inline and online measuring instruments provide real-time data for process control, allowing for high production quality. Furthermore, comprehensive monitoring and control of process parameters and subsequent documentation ensure that legal and commercial criteria are met.

Process refractometers were developed for monitoring and controlling liquid and pasty process flows. They can be used for continuous, extremely accurate, real-time substance identification and determination of critical factors such as the concentration and purity of solutions


10 Criteria for Selecting Your Optimal Weighing Solution

Do you really know what criteria are key to selecting a scale that ideally suits your needs? Nowadays, scales are offered in such a wide range of shapes and sizes that choosing one can be a daunting task. As a rule of thumb, a scale's suitability is determined by its application and ambient conditions. Detailed knowledge about the various selection criteria can be very helpful when selecting the scale that is best suited for your specific application. The following sections will give you an understandable overview of the various points to consider.

Enhanced Sterility Assurance

in Stopper processing: A Unique System to Unload Stoppers from a Stopper Processing System


Stoppers for pharmaceutical primary packaging must preserve the safety and efficacy of injectable drugs. Thus, before their intended use, these stoppers undergo multiple processing steps, including washing, rinsing, siliconization, steam sterilization and drying. Each step is critical to ensure the physical and mechanical properties of the stoppers by reducing particles, adding the appropriate silicon volume, sterilizing and avoiding re-contamination due to residual moisture. An additional critical step after the stopper processing is maintenance of closure integrity until filling in aseptic conditions. This paper discusses the validation of the transfer of stoppers from a stopper processing system, using a new aseptic transfer technology. It demonstrates that this technology maintains the sterility of the stoppers after their transfer into sterile single-use bags in an ISO Class 7 or 8 environment

Process Control Using Conventional Methods is Not Always Ideal

Usually, regardless of whether the moisture content of the materials is the only parameter that must be monitored and controlled, or whether other factors such as protein and fat content must also be taken into account, the measurement technology used only allows for random samples to be monitored. Taking moisture content measurement as an example, it is easy to see why conventional methods are not always the optimal solution for controlling a process and therefore are only suitable for optimizing the use of raw ingredients to a limited extent. The conventional process for determining the moisture content of a material is known as the oven drying method, during which up to 24 hours are required for analysis. In this method, a sample is dried and then weighed to calculate the weight lost during the process. A faster tool than the oven is a drying scale, which dries the sample directly on the scale using a radiant heater or microwaves and then measures the weight lost. Other conventional methods include "analytical" methods, such as Karl Fischer titration, the calcium carbide method, and the phosphorus pentoxide method; however, these methods require more complicated equipment than thermogravimetric methods. These processes are also waterselective, meaning they detect only the water content and not total moisture levels, in contrast to thermogravimetric methods. The aforementioned methods have considerable disadvantages: they only work with relatively small sample quantities and therefore are not sufficiently representative, they damage or modify the sample to be analyzed, and the analysis takes several minutes or more. For these reasons these methods are only suitable for random sample measurements. Complete monitoring of the entire process with full documentation or even direct, fullyautomatic process control is not possible with these methods. In a production phase with a high throughput, this means that several tons of a product with the wrong moisture content may be produced before this is corrected within the process