Screen Printed Ion Selective Electrodes as a Fully Integrated PAT Tool: Application to the Analysis and Impurity Profiling of Diatrizoate Sodium

Abstract

Conventional pharmaceutical manufacturing is generally accomplished via batch processing followed by laboratory testing conducted on some representative samples collected to evaluate batch quality. However, today significant opportunities exist for improving pharmaceutical quality assurance through innovation in process development and analysis. FDA's guidance for pharmaceutical industry has defined Process Analytical Technology (PAT) as a system for designing, analyzing, and controlling manufacturing through timely measurements, with the goal of ensuring final product quality. Nevertheless, pharmaceutical companies are encouraged to develop and implement innovative PAT tools for designing, analyzing, and controlling manufacturing through real-time strategies (i.e., during processing) of critical quality attributes of raw and final product. The goal of PAT is that quality cannot be tested into products; it should be built-in or should be by design. Furthermore, FDA stated that sensor-based measurements could pave the way to built-in product quality assurance which is the key to PAT development. From this perspective, this scientific approach presents screen-printed ISEs (SPEs) as a potential real-time analyzer and PAT-tool. Diatrizoate sodium (DTA) was chosen as a model analyte, it is a widely used X-ray contrast agent that is susceptible to degradation into a cytotoxic and mutagenic compound, that can be also used as its precursor. Two SPEs were fabricated and used successfully in the analysis of both DTA and its potential impurity. The proposed SPEs have the advantage of being real-time analyzers that could be fully integrated into the production cycle giving a key to a promising competent PAT-tool.