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Awards given at BPC included one for lifetime
achievement and one for industrial achievement. Lin-Nam Wang (on the
staff of The Journal) reports on the winners’ lectures
A world of neglected dimensions
Professor Florence: working with simple systems will, perhaps, explain
more complex ones |
Sandy Florence, dean of the School of Pharmacy, University of London,
received the Journal of Drug Targeting annual lifetime achievement award.
His award lecture was entitled “Nanotechnology: reinventing colloid
science?”, allowing him to return to his PhD subject.
In order to consider whether nanotechnology is a continuum of colloid
science or a new break, Professor Florence gave a review of the history
of colloid science. “The term ‘nanotechnology’ appeared
after nanosystems — nature got there long before the terminology,” he
said. The term “colloid” was coined by Thomas Graham (1805–69),
but it was not until the 1927 that Wolfgang Ostwald drew attention to
modern colloid chemistry in his book, “The world of neglected dimensions” — neglected
because at the time, the particles could not be seen with the instruments
available. During his lecture, Professor Florence took the audience into
this world with the benefit of visualisation technology. He showed slides
of nanoparticles moving through lymph and being manipulated in different
ways.
Professor Florence talked about trying to use nanoparticles as drug carriers
and their distribution in the lymph and blood, which can be difficult
to model. He described how minitubes can be fabricated by pulling a cell
apart to form tethers, then micromanipulated and laid down to act as
vesicular shuttles through which nanoparticles can move. This provides
a model to study a nanoparticle moving through a small capillary so we
can begin to understand a simple system to describe a complex phenomena.
Similarly, tracking the movement of nanoparticles inside a confined space,
such as a vesicle, allows a diffusion coefficient to be determined and
researchers can begin to look at how the charge of a particle affects
its movement and how the nature of the membrane affects movement.
The interpretation of such simple systems is not difficult, Professor
Florence said. “In the past, we looked at clear solutions, knowing
there were colloids there, but now we can see and visualise them and
the software is available now to help us analyse the phenomena,” he
explained.
Professor Florence also described coating nanoparticles with surface
proteins from Listeria monocytogenese to prevent aggregation. “Aggregation,
flow, adhesion. These are all the stuff of colloidal chemistry from Thomas
Graham’s time, that I think are so vital to drug delivery now,” he
said. Professor Florence concluded that, to some extent, nanotechnology
is a continuum of colloid science, but that “it does not matter,
whether we work with nanoparticles or microparticles, the same rough
concepts apply”. He commented that undergraduate students find
stability and emulsion science boring. However, “when we look at
the possibility of giving them these systems as drug delivery carriers,
where there is basically the same chemistry, we have some chance,” he
said.
Accepting the lifetime achievement award, Professor Florence said that
although the award was precious to him, he was not sure about the “lifetime
epithet”. “There is life in the old dog yet,” he declared.
Conference on over-regulation may be needed
Clive Wilson, professor of pharmaceutics, University of Strathclyde,
was awarded the GlaxoSmithKline international achievement award. Professor
Wilson has pioneered the use of gammascintigraphy in investigating drug
delivery to the gastrointestinal tract and the eye. The latter was the
main theme of his award lecture.
Blindness is a condition people fear more than cardiovascular disease
or cancer, Professor Wilson said. He highlighted the restrictions on
drug delivery to the eye, such as irritation potential and blurring of
vision, particularly problems delivering to the back of the eye. Adding
small amounts of a gamma emitter to an eye formulation allows researchers
to look at its clearance.
According to Professor Wilson, the development stage between the bench
and the patient is about making global models to understand processes
and find out what attributes of a material equate to good performance.
Models that he has worked with include bulls’ eyes. These can be
kept alive and cameras or spectrophotometers put inside to look at drug
movement. Such a model may be bigger than a human eye, but adjustments
can be made to compensate.
During his lecture, Professor Wilson also shared his views on the difficulties
of getting a drug from the bench to the patient. The pharmaceutical industry
is facing serious issues, he said. Despite huge investment, there are
not enough new compounds with appropriate drug-like characteristics and
the biotechnology boom has failed to deliver. Some think that medical
devices are the way forward, but the problem is that the innovation has
totally outpaced the time required to test their performance in patients,
he added. “What has happened is that the pathway between the preclinical
and the final launch
has got longer and longer and longer,” he
explained.
“We have got to accelerate development. Delays cost money and add
to the cost of the goods,” he added. In a typical university such
as Strathclyde, there are codes of practice for investigations on human
beings. But Professor
Wilson’s concern is that things have gone further than codes to
protect the patients. “Now things are being assessed for management
issues. They are then going to two ethical committees, before ending
up at the hospital ethical committee,” he said.
As an example, Professor Wilson pointed out that it had taken a year
for one of the researchers presenting a poster at BPC to get her study
through all the committees. “That is inappropriate and not proper.
I am not saying that we should ever compromise safety, but sooner or
later we will have to have a conference on over-regulation,” he
said. |
The
Pharmaceutical Journal