By Brian Wallheimer
The efficacy and efficiency of a pharmaceutical drug
depends highly on how the crystalline structures of
the drug dissolve, and that has everything to do with
how the crystals in those drugs are built.
Zoltan Nagy, professor of chemical engineering,
is pioneering new ways to control the formation
of crystals in many products including food,
agrochemicals and pharmaceuticals.
His research team creates hardware, software,
algorithms and feedback strategies to control even
the most minute details of a crystal's size, shape and
purity — all key to the properties a solid exhibits, be
it the way a piece of chocolate melts in your mouth
or how a drug works when taken by a patient.
"If you take a painkiller, whether it works in three minutes
or 20 minutes has to do with how it dissolves," Nagy says.
Crystallization is a low-energy method for creating
pure solids from liquids. Creating those crystals in
pharmaceuticals tends to occur through trial and
error, and that process can take as long as six months
According to Nagy, that means millions of dollars
in development and product lost in trials that don't
Having a method to control crystal formation with
certainty also means that a bad batch of drugs
with minor but important differences can be all
but eliminated, says Gintaras "Rex" Reklaitis, the
Burton and Kathryn Gedge Distinguished Professor
of Chemical Engineering. Slight differences in the
crystalline structure can lead to differences in drug
performance and unwanted side effects, Reklaitis says.
"Zoltan has been championing the idea that if you
have good online measurements and a good model,
you can use innovative, model-based, feedback-control strategies. Every batch is the same," says
Reklaitis, who collaborates with Nagy. "Professor
Nagy's technique definitely has significant patient
implications and also hopefully means you'll have
less wasted product."
Nagy adds, "You use much less product with more
precise methods. You can bring the drug faster to the
market and it will be cheaper."
Reklaitis says there are examples of pharmaceutical
companies having to discard drugs when the
process they were using to crystallize molecules
stopped working, costing sometimes hundreds of
millions of dollars.
"When a company has a bad batch, they get rid of it.
They can't sell it," Reklaitis says. "And someone has to
pay for that. The cost gets passed on to patients."
Nagy, a member of the Purdue faculty since 2012,
has spent more than a dozen years in the research
areas of advanced process control, process analytical
technologies, and crystallization modeling and
He is in the second year of a five-year appointment
as a Purdue University Faculty Scholar, a University-wide honor for select mid-career faculty who are on
an accelerated path for academic distinction.
Sponsored research funding for Nagy and his
collaborators' work has exceeded $11 million from
government agencies such as the U.S. Food and
Drug Administration, as well as from collaboration
with pharmaceutical industry leaders Eli Lilly & Co.,
GlaxoSmithKline and Pfizer, and spice and herb
extract producer Kalsec Inc.
He has more than 200 publications in these
areas, and has given numerous invited talks at
conferences, universities and companies worldwide.
He also is founding editor of the pharmaceutical
engineering subject area of Chemical Engineering
Research and Design.
Nagy discovered his passion for crystals with his
childhood chemistry set. When he started his career
as an engineer, he realized he could take that love
and use it to solve difficult problems and create
"Scientists like open questions, and there is a
big impact if they are solved," Nagy says. "It's a
fascinating process to try to control."
How Zoltan Nagy's Work Is Reducing Time and Costs for Pharmaceuticals Approval