Modern drug counterfeiters may be well-funded and have access to modern pharmaceutical machines, so the products may be indistinguishable from the authentic one. This forces the legitimate drug companies to resort to more sophisticated security measures to reduce counterfeiting.
In the past, some counterfeits were relatively easy to spot:
(1) tablets or capsules that were the wrong shape, size or color
(2) lack of or incorrect pill markings
(3) wrong packaging, which may be subtle (involving serial numbers, stoppers, container dimensions, labels, inserts)
(4) wrong pill characteristics (easily crumble or break apart, etc.)
The most accurate way of detecting a fake drug is to analyze it for its actual content. However, this is relatively expensive and takes time, especially for a developing country with limited resources. Methods may involve:
(1) chromatography (HPLC, other)
(2) mass spectrometry
(3) nuclear magnetic resonance (NMR)
What is needed is a means of easily screening products for likely counterfeits. This can be done by:
(1) careful attention to the colors used in packaging
(2) scanning of tablets or pills using near infrared (NIR) or Raman spectroscopy
(3) simple chemical analysis (colorimetry, thin-layer chromatography)
A simple chemical analysis often can only tell if the target compound is present and roughly how much. It cannot identify what else may be in the formulation.
Legitimate drugs may have problems in field analysis due to:
(1) lot-to-lot variations in packaging
(2) absorption of moisture once a package is opened
(3) the curved surface of tablets (if being scanned in spectrometer)
(4) coatings
