The final product must be tested for compliance with various quality standards as part of the medication development and production process. For medications ingested in tablet form, it is important
Thus, in order to get the best optimal product standards, tablet dissolution tests are conducted. However, these tests are very time-consuming because they must be performed on six tablets at several specific call-up points. This is referred to as dissolution profile. The samples must be filtered before analysis in order to measure them photometrically afterwards. This is not only time-consuming, but also prone to error due to the fact that it is a manual procedure.
Optical spectroscopy combined with robot technology represents an efficient and reliable solution for automating the analysis of tablet dissolution tests. The optical spectroscopy method is based on measuring absorption in the visible and/or the UV range (UV/Vis). When analyzing tablet dissolution tests, the absorption of the ingredients is measured with a precise optical path length, similar to cuvettes. However, this can be done without taking a sample. Instead, fiber-optic light guides connect the immersion probes to the diode array detector (DAD) spectrophotometer. The probe allows a measurement point directly in the dissolution container and can be moved for the systematic measurements in different vessels with the help of a robot arm.
Since this automated system performs several different tasks, the robot arm is designed to correctly position all tools, tablets and immersion probes. Automated, sequential measurements can thus be performed in an efficient, simple and time-saving manner.
Tablet dissolution tests are usually conducted in the UV/visible range. The visible range is primarily used to correct the influence of particles that may be found in the measuring slit of the immersion probe during the measurement because tablets that crumble do not completely dissolve. It is typically individual particles from the excipients that remain and then flow along with the medium through the measuring slit. The stray light that this generates would influence the spectroscopic measurement or create spikes in the data. The measurements performed using a DAD spectrophotometer, allow a complete UV/visible spectrum to be recorded in less than 20 milliseconds. This method does not cause particles to generate spikes, but rather only minor fluctuations that can be subtracted using an algorithm.