Raw materials identification faces ever-increasing regulatory pressure for pharmaceutical manufacturing, with 100% testing of containers being desirable or essential. Cobalt Light Systems’ RapID is a unique solution for high-throughput testing that achieves the greatest reduction in testing-time and resource requirements.

Testing incoming raw materials is essential for pharmaceutical manufacture, for both the active ingredients and also the excipients making up the rest of the formulation. Individual raw materials require specific tests before release to manufacturing, including particle size, residual compounds and even odour. These kinds of quality tests are usually performed on a small sample of the goods – only a few percent of incoming containers. However, ID testing encompasses up to 100% of the received containers and is highly resource-intensive.

Regulators may mandate or strongly recommend 100% testing (see, for example, the harmonisation of international GMP standards by PIC/S) and spectroscopic methods are becoming standard. Traditionally, this has meant mid-infrared or near-infrared, but Raman spectroscopy is the fastest-growing tool for raw materials identification (RMID) due to its high selectivity, ease of use and relative insensitivity to sample preparation and presentation.

The impact on cost and resources of increasing the number of containers tested is significant. However, the largest cost is often due to the cost of handling and sampling the containers, and reducing this burden is paramount in quality control.

Problem: the high cost of sampling containers

Raw materials are received in sacks, tubs, bottles, jars, flexible intermediate bulk containers (FIBCs), plastic drums, barrels, metal or other containers. Most of these are not amenable to traditional spectroscopy as they need to be substantially transparent; for example, thin polyethylene sacks.

Without a line of sight, conventional Raman is limited in its applicability – even the amber glass of a 2L bottle is too much for the ID of most materials because of the strong bottle fluorescence. Therefore, testing most materials requires the container to be opened. Since the contents have not yet been identified, they must be safely opened in an expensive sampling booth. For sterile or hygroscopic materials, this may mean opening each container in a controlled environment.

The total process involves: moving the materials from quarantine, opening each container, sampling or inserting a probe, resealing the container, cleaning up the residue displaced from the container, removing the container, cleaning the booth and, optionally, validating the cleanliness of the booth. The resources and time taken to do this is high and there is a risk of contamination.

Suppliers could deliver their products in transparent packaging. However, this is very rarely done and would require a (generally prohibitive) cost in recertifying the incoming goods.

Solution: don’t open the packaging

The solution is to avoid sampling the container altogether. Cobalt’s RapID instrument performs Raman ID verification through unopened, non-transparent packaging for most common raw materials. By using a technology called spatially offset Raman spectroscopy (SORS), RapID can perform ID tests through millimetres of opaque plastic, two to four layers in a paper sack and large containers such as FIBCs. By removing the sampling process, the ID can be performed by warehouse staff in five to 20 seconds, immediately after receipt of the goods.

For a pallet of sacks, the time taken to ID the contents can be reduced by eight to ten times compared with conventional handheld Raman instruments, and by a greater amount compared with other spectroscopic or wet testing methods. There are no consumable items required and the cost of installing, maintaining and cleaning sampling booths is avoided.

Due to other differences with handheld Raman instruments, RapID is more broadly compatible with contents that are otherwise difficult. For example, biopharmaceutical raw materials such as growth media in white plastic bottles can be quickly identified without the risk of contamination or any impact on the sterility of the contents.

RapID is unique in enabling the ID of materials in a wide range of containers without sampling, with significantly increased testing throughput and fewer resources. RapID also maintains sterility and avoids contact with hazardous materials. 