RAMAN SUPPLEMENT


be transferred. The potential for Raman is that methods based on Raman can save time during transfer where an alternative R&D analytical approach may not be appropriate for manufacturing and where effort and time are expended while an appropriate analysis method is developed and validated.


What advancement in Raman spectroscopy instrumentation has had the most impact in pharmaceutical analysis? What do you think the next technological breakthrough will be and what is its major application?


Pavel Matousek: Detection, filter and laser technologies have made dramatic advances over the last decade, permitting the development of robust, sensitive and com- pact instruments that can be deployed in the field and operated by non-experts. The recent extension of Raman to intact analysis of tablets and capsules through transmission Raman spectroscopy offers potential usability and ease-of-deployment benefits in rapid quantitative analysis.


Ian Lewis: It really depends on the timeframe of the questions. FT-Raman in the early 1990’s started to raise awareness of Raman possibilities in research, compact components that led to the rise of compact Raman microscopes (mid- 1990s), in-situ analysers (mid-1990s) and most recently hand-held instruments (2006) However, over the last decade, the


development of sampling devices and approaches has probably had the most impact, whether this is for in-situ lab analysis, in-situ manufacturing, transmission analysis for solids formulation, Raman microscopy for chemical imaging or statistical sampling. Now instead of tediously preparing a sample, the sample may be analysed with relatively low or no-preparation.


Mike Claybourn: Fast, high spatial resolution for problem solving formulation issues in development and manufacturing optimisation. Portable Raman systems are important in raw materials ID and product security. Transmission Raman is being driven by early adopters. The next generation of low cost systems will have a major impact. This technology has a good chance of replacing some HPLC methods in formulation / process design and stability


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European Pharmaceutical Review Volume 16 | Issue 5 | 2011


studies. Smarter systems that are designed for the application and the user.


Mike Kayat: The availability of portable Raman instruments is now expediting the analysis of incoming raw materials by moving the verification from the lab to the warehouse. The sampling and testing activities can be significantly streamlined, so on the spot checks are possible without the need for sample handling in quarantined areas. The industry is moving to 100 per cent analysis to meet increased regulations. The next breakthrough will be handheld Raman instrumentation with laboratory quality resolution and accuracy, coupled with high speed chemometric analysis. With wireless capabilities, they can be updated with libraries, methods and models with utilities like barcode readers and GPS from a central site directly interfacing with pharmaceutical ERP systems.


Ken Williams: Recently, there has been a significant reduction in the time required to collect Raman images. Initially, it could take hours or days to record a chemical image over a small area as a ‘representative’ sample. Nowadays, entire tablets, comprising thousands of spectra, can be imaged in minutes. The next advance could utilise this imaging technology in a process control environment or in the development laboratory.


Raman spectroscopy is perceived as being a niche technology. What are the major challenges and/or blockers in moving Raman spectroscopy from specific applications to wider usage? Or is that not a realistic goal?


Pavel Matousek: One blocker is the historical perception of the technique as being a specialist tool and the slow change of culture in pharmaceutical industry. The recent explosion of applications with the advent of robust portable and handheld Raman instruments in analytical areas outside pharmaceutical settings heralds its much wider use in pharmaceutical analysis too.


Ken Williams: Raman spectroscopy is difficult because of the low signal levels, the possibility of fluorescence masking, and the variation in spectra because of resonance effects. However, these issues can be overcome by a combination


of flexible hardware and advanced software, enabling Raman's advantages – such as easy sample preparation – to be fully exploited.


Mike Kayat: This is a realistic goal. Raman spectroscopy is one of the fastest growing segments in the molecular spectroscopy market with applications in chemicals, food and beverage, pharmaceuticals, and security. A current challenge slowing down the adoption of Raman spectroscopy is that the instrument validation can take time due to the complexities in calibrating the units and lack of chemical


reference standards. However, standards and guidelines have been developed for Raman spectroscopy that are now being adopted industry wide.


Ian Lewis: Time and successes are probably the easiest to identify with. Without success stories, Raman remains an expert’s technique with applicability in a lot of niches within the pharmaceutical market. In the last six years, both the USP and their European Pharmacopeia equivalent have released monographs on the use of Raman (USP 1120 and 2.2.48). The lack of


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