Drug delivery developers need more focus on the shape of the carrier, rather than the size and surface chemistry, according to a new study.
In the paper, titled Effects of Drug Carrier Geometry on Drug Delivery , author Shehu S. Mamman-Aka’Aba stresses the importance of drug carrier geometry to develop more accurate delivery systems; focussing especially on transport in the blood vessel.
The article cites a recent in vitro study by Doshi et al , published in 2010, that used synthetic microvascular networks (SMN’s) to mimic endothelial cells. Doshi found that rod shaped carries attached themselves the best.
However Aka’Aba – a pharmacy student of Reading Univeristy, UK – said the reason more researchers concentrate their efforts on the size of the molecule is that in vitro methods are often not sophisticated enough to replicate physiological conditions.
“Improvement in this regard could lead to an explosion of interest and research in this area of study. Achieving parity could lead to better drug targeting, reducing dosing sizes, adverse effects and cost per dose of medication,” he told in-PharmaTechnologist.
He also said that more accurate equipment is needed to measure geometry of drug carriers in vivo.
In the paper, published in Student Pulse, Aka’Aba wrote: “Traditional drug delivery development has often neglected the study of drug carrier shape in favour of size and surface chemistry due to the inadequacy of apparatus to mimic in vivo conditions and difficulty in pin pointing confounding parameters.”
He added that though several studies have shown the importance of geometry in drug carrier transport, the implication for the drug formulation process is still yet to be fully understood.
“Research needs to be undertaken in more complicated SMN’s perhaps incorporating the use of endothelial cells in the SMN’s to obtain more valid data that can be extrapolated to in vivo conditions,” Aka’Aba concluded.
Industry changing shape
Aka’Aba’s paper is not the only study to have focussed on carrier geometry in recent months.
In November, in-PharmaTechnologist covered research led by Antonios Kanaras at the University of Southampton , which looked at four different morphologies of gold nanoparticles to target endothelial cells.
And in a recent drug-delivery round-up, we covered work on shape-changing nanoparticles at the University of Sheffield .
Lead researcher Stephen Ebbens said the carriers could change shape to navigate the body’s blood system by itself, therefore eradicating the need for invasive nanoparticle delivery.
As for the future of the industry, Aka’Aba added: “In my opinion, the next big break will be the development of a licensed formulation with drug geometry at the heart of its pharmacological action.
“This will most likely be for an indication such as atherosclerosis or for a respiratory indication, like Asthma.”