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A new method of delivering tuberculosis (TB) drugs to sufferers of the disease using nanotechnology is being developed by the CSIR.
The TB nano-drug delivery project seeks to address patient non‑compliance in TB control programmes through the development of a system whereby the administration of drugs can be drastically reduced.
"The CSIR has been successful in nano-encapsulating four first-line anti-TB drugs, i.e isoniazid (INH) and rifampicin (the most potent anti-TB drugs on the market), as well as pyrazinamide and ethambutol in a biodegradable polymer with particle size ranging from 186 to 290 nm, through a double emulsion solvent evaporation method. This is the required size for oral nano-drug delivery. By altering the method the CSIR has managed to make microparticles ranging from 700 nm to 500 um, suitable for pulmonary delivery.
Reduced dosage
Collaboration
Related research projects
Reduced dosage
The main objective of the CSIR study is to address patient non-compliance in TB control programmes. The project seeks to develop a system whereby anti-TB drugs can be administered in a reduced dose frequency, i.e. once every seven to ten days, as opposed to the current regimen of four antibiotics taken daily for six to nine months. By shortening the duration of the treatment from six months to between two and three months, patient compliance will improve substantially.
The slow release treatment should minimise multi-drug resistant (MDR) TB (through improved compliance) and hopefully contribute meaningfully to total elimination of TB. This delivery process has huge potential to be used for other pharmaceuticals once optimised, not only in the case of TB, but also malaria and HIV treatment.
Tuberculosis is gaining ground: In 2001, the disease killed more people than any previous year in history. Globally, there is a 3% increase in new TB cases each year, while in Africa, the increase is 20% per year, largely due to co-infection with HIV/Aids. Every year, eight million people worldwide develop active TB and three million die from it, while more than 400 000 new cases of MDR TB are diagnosed.
Although an effective therapeutic regimen is available, patient non-compliance (because of the need to take anti-TB drugs daily or several times a week for at least six months) results in treatment failure, while the emergence of drug resistance can lead to MDR-TB. Not a single new class of TB drug has been developed in over 40 years. That means that today’s TB patients, rich and poor, are still treated with drugs discovered 60 years ago. Research and development of new TB drugs languish under a perceived lack of need in the developed world.
The drawbacks of the conventional chemotherapy necessitate the development of a delivery or carrier system to release drugs slowly over extended periods of time.
The CSIR has been successful in nano-encapsulating four first-line anti-TB drugs, i.e isoniazid (INH) and rifampicin (the most potent anti-TB drugs on the market), as well as pyrazinamide and ethambutol in a biodegradable polymer with particle size ranging from 186 to 290 nm, through a double emulsion solvent evaporation method. This is the required size for oral nano-drug delivery. By altering the method the CSIR has managed to make microparticles ranging from 700 nm to 500 um, suitable for pulmonary delivery. The nanoparticles are submicron-sized (less than 1 micron) polymeric colloidal particles with a therapeutic agent encapsulated within their polymeric matrix, or adsorbed or conjugated onto the surface. The release of the active agent may be constant over a long period; it may be cyclical; or it may be triggered by the environment or another external event.
The technology is currently undergoing pre-clinical trials.
Collaboration
The project is led by the CSIR operating with a South African TB consortium consisting of the Universities of South Africa (UNISA), Pretoria and Stellenbosch, as well as the Medical Research Council. Other current and potential partners are North-West University, University of London – UK, Nottingham University – UK and Aktiv Dry Pharmaceuticals - USA. The main project sponsor is the Department of Science and Technology (DST).
Related research projects
Encapsulation of lead compound funded under the India-Brazil-South Africa scheme
Publications
Primary contact
Dr Hulda Shaidi Swai
CSIR Materials Science and Manufacturing
Tel: +27 12 841 2366
hswai@csir.co.za
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