Professor Yahya Choonara designs new and innovative ways of delivering drugs into the human body with the intention of reducing side effects, enhancing drug bioavailability and improving patient compliance. He is an associate professor of pharmaceutics in the department of pharmacy and pharmacology at the University of the Witwatersrand (Wits) and the research manager of the Wits advanced drug-delivery platform. He has published over 60 research papers and presented over 150 conference papers, although he is only 31 years old.
His research focuses on the development of rate-modulated biodegradable polymeric devices for prolonged drug delivery. "'Polymers' describe material that controls the release of the drug," says Choonara.
His work in intraocular implantable drug-delivery devices to treat posterior segment eye diseases is of particular interest. An example of this type of eye disease is cytomegalovirus retinitis, an infection in HIV/Aids patients that often leads to blindness. Current successful treatments can be very expensive and, if embedded in the eye, need to be removed later.
Choonara's design is a patent-pending biodegradable doughnut-shaped mini-tablet (DSMT) device that can provide constant drug release for six months to a year. Insertion involves initial eye surgery. The technology is simple to manufacture and a cost-effective treatment for these eye diseases.
"The DSMT device can be used for many diseases that require chronic suppressive maintenance therapy," says Choonara.
It can be placed anywhere in the body and doesn't need to be removed owing to its biodegradable properties. Examples of applications include the alleviation of chronic inflammation and as an intrauterine device.
Choonara is also co-inventor of over 30 filed patents in drugdelivery technology. Wafer formulations, for example, are taken by mouth and dissolve in seconds. This is particularly useful for paediatric use but there are numerous other applications.
As part of his unique research approach, Choonara developed new ways of using existing software in the development of drug-delivery technology that allows formulation scientists to reduce experimentation time in the lab and on animals, and reduces cost.
While doing his undergraduate degree in pharmacy, Choonara was drawn to pharmaceutics and ways to design effective new formulations.
"Because many new drugs aren't stable, it was clear that there was a need for improved delivery systems to formulate drugs into effective products. Designing new drug molecules is very expensive and these need to be delivered effectively into the body," he says.
In South Africa the Wits drug-delivery platform is the only platform in its domain. It is directed by Professor Viness Pillay, who is a National Research Foundation/department of science and technology research chair, professor of pharmaceutics and head of pharmaceutics and pharmaceutical research at Wits. "I would like to acknowledge my mentor, Professor Pillay, who has been instrumental in allowing me to follow this vibrant path of research," says Choonara.
Choonara has his eye on a number of exciting research areas. "An example is using electronics and stimulatory response mechanisms in drug delivery," he says. "In future we may see drug-delivery systems in the body controlled by an external interface such as an iPad or cellphone."