Intertek ASG Laboratory, Manchester, UK

NMR Screeing for the Detection of Counterfeit Drugs

Pharmaceutical analysis is highly regulated and validated proprietary or pharmacopoeia methods are needed to fully assess the quality of pharmaceutical products. With increasing global trade and major industry concerns around counterfeit drugs, there is also the need for efficient screening methods to supplement the typically labour intensive official methods.

The Intertek ASG Laboratory is supporting pharmaceutical clients in this area by applying NMR procedures to both identify and quantify active pharmaceutical ingredients (APIs) in pharmaceutical products. The methodology involves solvent extraction and quantification using appropriate internal standards.

The methods, applied without detailed product specific validation, have highlighted cases where APIs were absent from the product and other cases where API levels were at major variance with the stated dose. Where issues such as these are highlighted, it is important to then apply validated methods to investigate further.

Benefits of NMR include:

Identification of the Active Pharmaceutical Ingredient (API) can be carried out in the presence of various excipients
Once the presence of the API is confirmed, quantification can be carried out using an internal standard of known purity

Complementary techniques available:

Raman Spectroscopy
- Raman is a non-destructive technique and analysis can be carried out in the blister pack
- API's tend to give stronger Raman signals than excipents
- Useful for multiple sample (QC) analysis - quantification is possible but instruments need to be calibrated using neat API
X-Ray Diffraction (XRD)
- XRD can be extremely effective at monitoring subtle changes in structure and crystallinity of pharmaceutical materials
- Ideal for the examination of counterfeit API's by a direct comparison of the diffraction pattern obtained from the original against the counterfeit
Surface Analysis