by Rady Ananda
29 June 2012
To clean up its drugs that are contaminated with
ingredients (which are also carcinogenic),
Big Pharma may deploy lab-created,
nanosized, polymer-based scavengers.
But is the cure any safer?
New research explains that:
A variety of chemical compounds,
intermediates, and reagents are used during the process of
synthesizing active pharmaceutical ingredients (APIs).
Some of these chemicals,
intermediates, and reagents, as well as byproducts of synthetic
processes, can have toxic properties and be present as
impurities at low levels in the API or final drug formulation...
The kinetics of acrolein scavenging in the presence of the API
iodixanol and the scavenging capacity of resins were
demonstrated in this paper.
They found a nanopolymer so efficient it
cleans up 97.8% of acrolein without eating the active pharmaceutical
“Pharmaceutical genotoxic impurities
may induce genetic mutations, chromosomal breaks, or chromosomal
rearrangements, and have the potential to cause cancer in
human,” lead researcher Ecevit Yilmaz told
“Therefore, exposure to even low
levels of such impurities present in the final API may be of
significant toxicological concern.”
Research began in earnest after the
European Medicines Agency issued its
Guideline on the Limits of Genotoxic
Impurities in 2006, which set the limit at 1.5m/day under
the Threshold of Toxicological Concern (TTC):
A TTC value of 1.5 μg/day intake of
a genotoxic impurity is considered to be associated with an
acceptable risk (excess cancer risk of <1 in 100,000 over a
lifetime) for most pharmaceuticals.
The US Food and Drug Administration
followed suit in 2008.
Some nanopolymer scavengers are more or less selective in their
activity, the team discovered, based on polymer structure. “Less
cross-linked ones showed an ‘undesired high level of nonspecific
binding to the API’,” meaning they readily eat the good properties
of the drugs, and who knows what else.
a 2008 study, mesoporous silica
nanoparticles (MSNs) were also found to “restore damaged cell
membranes and ameilorate abnormal mitochondrial behavior induced by”
genotoxins (like acrolein). “MSNs modified with drug/polymer
constructs provide significant neuroprotection to cells damaged by a
usually lethal exposure to acrolein.”
Safety questions for nano-agents remain, however. Because of the
size, a whole new set of health hazards are raised. Does this
technology trade one set of hazards for another?
Last December, a group led by the International Center for
filed suit against the FDA over
untested, unlabeled nanomaterials added to our food, cosmetics and
drug supplies. Represented by the Center for Food Safety (CFS), the
litigation forced the FDA into making some changes to its nanotech
explained that under the new
policy, “FDA acknowledged that there are differences between
nanomaterials and their bulk counterparts, and that nanomaterials
have potential new risks and may require new testing. However, the
agency declined to enact mandatory regulations at this time.”
George Kimbrell, CFS Attorney, provides this background:
Nanotechnology is a powerful new set
of technologies for observing, taking apart and reconstructing
nature at the atomic and molecular level.
Despite already being commercially
available, nanomaterials in sunscreens, cosmetics, foods and
food contact substances are unlabeled and largely untested for
their human health effects.
Existing research raises red flags,
indicating that nanomaterials have the ability to enter the
bloodstream through contact with the skin, ingestion and
inhalation, as well as move in the natural environment once
Not only that, nanosize particles easily
cross the blood-brain barrier and placental walls.
That small of a size makes
nanoparticles capable of crossing the blood-brain barrier
noted food research scientist Ellin Doyle. In 2006, she
published a literature
review on nanotechnology advising, ‘Nanoparticles are
readily taken up by many types of cells in vitro and are
expected to cross the blood-brain barrier that excludes many
substances that might harm the brain.’
In addition to several studies
showing nanosize-induced harm cited in ICTA’s
2006 petition, another
group, ETC, listed
ten studies from 1997
through early 2004 that showed DNA and brain damage, lung
dysfunction, and bioaccumulation (whereby earthworms and
other creatures absorb, inhale or ingest the nanoparticles
and pass them up the food chain).
2012 study shows that even
nanoparticles pass up the food chain to fish,
dysfunctionally affecting behavior and fat metabolism.
This is especially significant
as nanopollution grows with the release of thousands of
pounds of nanomaterials into the environment, notes Friends
of the Earth in its 2006 report,
Nanomaterials, sunscreens and
cosmetics. (More studies can be found at this
companion FOE report.)
ETC also pointed to studies
showing that nanoparticles can break down in the body
causing metal poisoning, and can cross the placenta from
mother to unborn fetus.
2010 British study
confirmed that anything smaller than 100 nm poses even
greater health risks because it can “access all areas of the
body” and can even penetrate the nucleus of cells where DNA
Stronger than steel, carbon
nanotubes look and act like asbestos,
which causes lung cancer.
FOE report also cites
reduced kidney growth in lab animals exposed to
Though the ICTA lawsuit demanded a
recall until nanomaterials are labeled and their effects tested for
safety, the only real change the six-year fight made is that the FDA
now admits that size matters.
After pushing the issue this long,
perhaps a different legal strategy is now needed to protect the
public from dangerous substances the FDA is not willing to control.
Meanwhile, we can expect some industry-sponsored toxicity studies on
lab-created, nanosized, polymer-based scavengers used to clean up
genotoxins in pharmaceuticals that we will ingest.
We can also expect, like with genetic engineering and nanofoods, no
US federal agency will require labeling.