World running out of antibiotics
UKZN medical team says delivery of drugs is issue,not resistance
IT’S BECOME a global health crisis that experts believe could eclipse the HIV epidemic if novel approaches to treatment aren’t created – and fast. Antibiotic resistance – dubbed as a “serious threat to mankind” by the World Health Organisation – has scientists scratching their heads trying to find solutions that can modify and maintain infection fighting properties of the drugs.
But, as a University of KwaZuluNatal team has asserted, the issue may not be in the drugs themselves but in forms of delivery that could be fuelling resistance.
As a solution, the university’s Novel Drug Delivery Unit is designing and manufacturing several innovative medicines that will target the very site of the infection which could spell the end of taking antibiotics for several days and improve the efficacy of drugs that are currently on the shelves.
The team, under the leadership of Professor Thirumala Govender and post-doctoral fellow Dr Rahul Kalhapure, said: “Infectious diseases, especially in Africa, are the main causes of death. And while antibiotics have revolutionised the treatment of infections, numerous limitations exist with their current dosage forms available for patient administration.”Almost all drugs given to patients have to be formulated into a dosage form such as tablets, capsules or injectables.
However, according to Govender, more often than not, once administered, only a fraction of the drug reaches the infection site, meaning the patient has to take the antibiotic numerous times a day over a course of days.
“This is a major reason for higher doses than required being administered and for patients suffering from severe side-effects… Poor solubility and stability of these drugs in these dosage forms is also a problem. These factors contribute to treatment failure, poor patient compliance, drug resistance and deaths.”
It is reported that around 700 000 people die every year as a result of drug-resistant infections, including drug-resistant tuberculosis, HIV and malaria.
And so Govender and her team are focusing on the development of innovative pharmaceutical formulation materials and nano drug delivery systems as solutions to overcome challenges with the current dosage forms. “We are using nanotechnology, which is the science dealing with the design, production and application of materials in the nano scale range. The delivery of antibiotics via nano-sized drug delivery systems such as nano particles, nano micelles, nano plexes, solid lipid nano particles, etc, instead of conventional dosage forms is being widely investigated as an approach to improving antibiotic delivery and eradicating microbial resistance,” Govender said. In one particular case, the researchers have just completed a proof-of-concept study where they designed and synthesised a novel type of lipid, which not only targets the infection site but also releases encapsulated antibiotic drugs and bind to bacteria.
The team’s study has been accepted for publication in Nano medicine: Nano technology, Biology and Medicine, a leading international journal in drug delivery.
“This medicine shows potential to target and release an antibiotic specifically at an infection site, maintain effective concentrations for extended time, and decreases exposure to other healthy sites and beneficial bacteria in the body.”
But, it will still be some time before this kind of medicine is available to humans.
Researchers need to conduct further research to optimise this medicine before it became available to the public. It would also be tested on animals before being introduced to humans.