The way forward for process monitoring and control

Fourier-Transform Near Infrared (FTNIR) spectroscopy, a rapid and gentle technique that can characterize all manner of organic and inorganic compounds, is seeing increased deployment in a variety of areas in the pharma industry. The technique is commonly used for goodsin and final product testing, but has also been successfully used for the online monitoring of blend homogeneity,¹ tablet content uniformity^2,3 and realtime analysis of hot melt extruders.⁴ The technique has also found significant use as a quality assurance (QA) and quality control (QC) tool in pharmaceutical solid dose manufacture.⁵

Unlike many other techniques used for QA and QC, such as gas or liquid chromatography, FTNIR does not require any sample preparation and can analyse directly through glass or plastic, which makes it particularly useful in raw material identification (RMID) where an incoming sample is analysed directly through the plastic bag without any preparation. The use of FTNIR in this area is already commonplace because of the relative ease of implementation and good return on investment (ROI). In some cases, companies have paid off the initial analyser investment within the first year of implementation because of cost savings in RMID alone.

Jeffrey Hirsch

Integration is key

To make the most of FT-NIR, the analyser must be thoroughly integrated into existing process control architecture, and results must be immediately available to the Distributed Control System or Supervisory Control and Data Acquisition system; otherwise, the time window in which to effect necessary controls closes rapidly. Without the time in which to act on analytical information, the results themselves are devalued.

One concern for many companies when it comes to FTNIR is the cost of deploying and integrating the analyser. If the upfront deployment costs are too high, then cost savings can be compromised, pushing ROI out further. To help minimize this, the integration of the online analyser must be simple and seamless without duplicated effort or rework. One solution is to link the analyser with either mid or toplevel process control systems via the use of standard process communications language, such as Object Linking and Embedding for Process Control (OPC) in concert with existing analysis standard operating procedures and qualification protocols in the native FTNIR software. This avoids issues that may occur because of system incompatibility and expensive specialized PC interfaces for some Programmable Logic Controller systems.

Data collection for analysers is usually part of a complete software package that may also include electronic customizeable SOPs, validation materials, chemometrics and qualification workflows, as well as being compliant with regulations such as 21 CFR Part 11 and USP <1119>.^6,7 To help prevent problems during implementation, development chemists or implementation specialists spend a significant amount of time perfecting and validating techniques and SOPs inhouse using analyser software packages, which include OPC, before deployment into manufacturing.

Using native analyser system software with highly interoperable protocols has already shown great promise for online NIR installations worldwide in reducing the burden of systems integration into process architectures. With the ability of FTNIR spectroscopy to lower costs and increase process knowledge in pharma manufacturing, the next step is to take those same tools that have found significant use in the laboratory and transfer them to the plant seamlessly.

Jeffrey Hirsch Chief Scientist — Molecular and Microanalysis at Thermo Fisher Scientific (WI USA)

References

1, S. Ellis, Pharmaceutical Processing (March 2003).

2. J. Hirsch and R.De Maesschalck, European Pharmaceutical Review, 1 (2004).

3. D. Xiang et al., Applied Spectroscopy, 63(1), 33–47 (2009).

4. S. Tumuluri Sri Venkata et al., Drug development and Industrial Pharmacy,30(5), 505–511 (2004).

5. H. Forcinio et al., Spectroscopy, 18(9), 16–19 (2003).

6. Electronic Records; Electronic Signatures 62 Fed. Reg. 13464 (1997).

7. United States Pharmacopeia and National Formulary (USP 31) 595–599 (Rockville, MD, USA 2008).