What is the most significant advantage for laboratory near infrared spectroscopy (NIR) analysis?
NIR spectroscopy provides fast, reliable and non-destructive measurements, and it can evaluate many different parameters. Laboratory NIR instrumentation is robust and flexible, and various sampling accessories could be used—depending on the sample nature—to improve the sample presentation. Modular sampling accessories allow for analyses of powders, granules, solids, slurries, gels, pastes, and turbid or clear liquids. Since NIR analyses are performed on unmodified samples, presenting the samples to the instrument is the most important aspect of NIR analysis. The modular design of laboratory NIR instruments ensures that analyses are optimized for specific sample types.
How can NIR improve the monitoring and control of pharmaceutical processes?
In the PAT framework, NIR can provide effective and efficient means for acquiring information to facilitate process understanding, develop risk-mitigation strategies, achieve continuous improvement, and share information and knowledge. The process environment requires robust NIR instrumentation with immunity to vibration, flexible sampling capability and fully integrated software that is easy to use—from the developer level down to the operator level. Some of the lessons that we have learned when PAT was in its infancy has led to improved probe designs and better sampling devices to overcome the sampling difficulties that have made certain applications challenging. With the advancement in sampling devices, NIR could be used for end point determination in critical process parameters such as blending, granulation and drying, as well as in-situ bioprocess applications. In addition to versatility, NIR is fairly easy to deploy and maintain in different manufacturing environments.
How does NIR spectroscopy align with efforts for environmentally-friendly “green chemistry”?
NIR spectroscopy offers many advantages: it does not require any additional reagents or wet chemistry because sample measurement is direct and non-destructive. Measurements are very fast, require practically no sample preparation, and do not need any costly or toxic reagents. Therefore NIR meets the sustainable << Green Chemistry>> principles of the United States Environmental Protection Agency.
Given that NIR is a relatively flexible technique with broad applications, what have been some of the more interesting applications of NIR in your opinion?
One of the most interesting applications that have been developed is the combination of NIR and Headspace Karl Fischer. By integrating NIR and Headspace KF, there is immense time savings, higher productivity, and more reliable results when compared with utilizing the methods separately—because combining the accurate results from primary KF titration methods makes the NIR calibration and optimization process much easier. KF-NIR is shown to be of particular interest to manufacturers of lyophilized pharmaceuticals or anyone needing a rapid, reliable and robust moisture analysis technique.
What do you think the future of NIR holds?
Continuous processing with real-time measurement has become hugely popular as the trend has changed from smaller batch to larger scale manufacturing. Continuous manufacturing provides opportunities for improvement in pharmaceutical manufacturing, including real-time product quality information. The current regulatory environment supports advancing regulatory science and innovation, which may include abandoning some traditional manufacturing practices in favor of cleaner, more flexible and more efficient continuous manufacturing. As pharmaceutical companies seek to explore the benefits of continuous manufacturing using QbD and design space exploration principles, the requirement to have fast, agile, flexible, and robust control systems such as NIRS becomes increasingly important. NIR process analyzer software with embedded automated archival and industry standard process communication protocols are becoming common. This allows process NIR instruments to be more easily integrated into the pharmaceutical production process.