Although most pharmaceutical imports are safe, inspectors from the U.S. Food and Drug Administration
have discovered toxic metals and other contaminants in imported products entering the country
at border crossings, import centers, international mail facilities, and at shipping ports.
Due to the sharp rise in the numbers of foreign imported products over the past decade, FDA
is exploring the use of rapid screening methods to increase the number of samples the agency
can investigate at the point of entry.
To be of use, rapid screening methods and devices have to be reliable, able to withstand
constant relocation, and remain accurate under unpredictable field conditions.
In addition, they must be fast, portable, user friendly and require little or no sample
preparation.
Some rapid screening devices are currently used by security personnel at airports and
other locations to detect explosives.
FDA researchers performed countless hours of laboratory testing and analysis in order
to develop new methods for these existing screening devices so that they could reliably
detect counterfeit or contaminated drug products.
To date, FDA researchers have developed new methods for four portable screening devices
that quickly identify tainted medicinal imports.
In 2008 FDA received 43 reports of people experiencing significant hair loss, muscle
cramps, diarrhea, joint pain or fatigue after taking certain dietary supplement products.
These reactions were later linked to dietary supplements that contained hazardous levels
of the heavy metal, selenium.
FDA researchers designed a method that uses a portable x-ray fluorescence instrument to
detect toxic metals and other unwanted materials in dietary supplements.
The XRF instrument can analyze many different types of material and the new methods enable
inspectors to determine if toxic impurities or hazardous levels of ingredients like selenium
are present.
The FDA next developed a method for Ion Mobility Spectrometer (IMS) to detect sibutramine in
dietary supplements imported to the U.S.
Sibutramine is an anti-obesity drug that was taken off the market in 2010 because data
showed it caused an increased risk of heart attack and stroke.
Field scans using the IMS method showed more than 25 percent of “weight loss” dietary
supplements coming into the country were positive for sibutramine.
Public health emergencies - such as the 2006 tragedy in Panama when nearly 100 people died
from taking cough syrup that contained the poisonous substance diethylene glycol –an
ingredient in anti-freeze- motivated researchers at FDA to develop field test methods for this
and other toxic contaminants.
Two instruments - Raman and Near Infrared Spectroscopy - have been rolled out to field-test
for diethylene glycol and other impurities.
Raman Spectroscopy has many benefits in the field, including speed and ease of sample
preparation- samples can be tested for contaminants or impurities directly, without any additional
preparation steps.
The Near Infrared Spectroscopy method developed by FDA researchers is used to trace contaminants
and impurities in raw materials.
This device can be very useful for probing bulk material with little or no sample preparation.
All of these systems feature automatic data analysis with a simple pass/fail result.
Analysis time is usually less than a few minutes.
Tainted samples identified by field tests are sent to FDA district laboratories.
There, FDA scientists confirm the accuracy of field screening results by retesting tainted
samples with traditional, comprehensive lab analyses.
These devices are currently being tested in several U.S. cities that receive a high number
of foreign shipments.
Based on the results of these tests, FDA will determine if these hand-held devices are ready
to take on screening at all U.S. ports of entry.
In the future, these rapid screening methods may be used to screen ingredients at all stages
of the foreign and domestic supply chain to further promote drug safety and quality.
FDA has met with Chinese and Indian government officials to discuss its portable rapid screening
program and develop future partnerships.
The agencies are working together to share knowledge and learn about different approaches
and techniques for screening pharmaceutical ingredients and products.
At home, the FDA will continue to expand and improve rapid screening efforts as part of
its mission to advance public health by helping speed innovations that make medicines and
dietary supplements safer.