All Things Chromatography

Thin Layer Chromatography used to detect counterfeit medication in India

Excerpts from a research article published at Plosone.org:TLC Chart

Pilot Study of Essential Drug Quality in Two Major Cities in India

India is an increasingly influential player in the global pharmaceutical market. Key parts of the drug regulatory system are controlled by the states, each of which applies its own standards for enforcement, not always consistent with others. A pilot study was conducted in two major cities in India, Delhi and Chennai, to explore the question/hypothesis/extent of substandard and counterfeit drugs available in the market and to discuss how the Indian state and federal governments could improve drug regulation and more importantly regulatory enforcement to combat these drugs.

Random samples of antimalarial, antibiotic, and antimycobacterial drugs were collected from pharmacies in urban and peri-urban areas of Delhi and Chennai, India. Semi-quantitative thin-layer chromatography and disintegration testing were used to measure the concentration of active ingredients against internationally acceptable standards. 12% of all samples tested from Delhi failed either one or both tests, and were substandard. 5% of all samples tested from Chennai failed either one or both tests, and were substandard.

Read the entire research paper by clicking here.

Topics: malaria, anti-malarial, Thin Layer Chromatography, testing, test

CDC recommends Thin Layer Chromatography to test anti-malarial drugs

The U.S. Centers for Disease Control and Prevention advise that, "Counterfeit (fake) drugs are products deliberately made to resemble a brand name pharmaceutical. They may contain no active ingredients or contain ingredients inconsistent with the package description."
Malaria treatment
For example, the CDC says, "In Cambodia in 1999, counterfeit antimalarial drugs were responsible for the deaths of at least 30 people. A recent survey in Southeast Asia showed that among 104 tablets presented as the antimalarial drug artesunate, 38% did not contain any artesunate."

Users of pharmaceutical products (not only antimalarials) should take the following precautions:

  • Travelers should purchase in advance, in their home country, all the medicines they will need.
  • Travelers should record the drug's generic and brand names as well as the name of the manufacturer; should they run out, they can look for the correct product.
  • Make sure that the drug is in its original packaging.
  • Inspect the packaging because many times poor quality printing indicates a counterfeited product.
  • Be suspicious of tablets that have a peculiar odor, taste or color, or that are extremely brittle.

The CDC recommends testing suspicious drugs.

"drug quality can be evaluated in the field by two simple, effective, and low-cost techniques: thin-layer chromatography (TLC) and colorimetry... The TLC technique consists of placing a spot of drug sample on a thin layer of silica attached to a plate of glass, aluminum, or plastic. The plate is then inserted into a vessel containing a solvent mixture. By capillary action, the solvent mixture creeps up the silica material and dissolves the sample. The drug sample consists of a mixture of drug and inactive ingredients. These compounds will have various affinities to the silica matrix and will migrate with the solvent at various speeds. This characteristic effectively separates out a mixture of compounds. After migration of the solvent is complete, individual components can be visualized by chemical treatment or ultraviolet (UV) absorbance. The distance that the components migrate is characteristic for each compound; therefore the active ingredient can be recognized by comparison with a known drug standard. The solvent can be modified to increase resolution between various components. This method is relatively inexpensive, specific, and sensitive. It is commonly used to assess drug quality."

Click Here for more details from the CDC.

Click Here to find out more about Thin Layer Chromatography plates and accessories.

Topics: Separation, malaria, anti-malarial, Thin Layer Chromatography, testing, test