"The presence of Isoniazid enhances the degradation of Rifampicin in the acidic environment of stomach which is reflected in impaired bioavailability of Rifampicin from Rifampicin-Isoniazid fixed dose combination (FDC) formulations. We have worked upon a capsule which uses special floating technology which does not allow the two drugs to interact," Prof Shishoo said.
"To improve quality of its formulation, a novel capsule has been prepared which when swallowed, releases Rifampicin in the stomach. It keeps the tablet floating in the stomach thereby retaining it for five to six hours. On the other hand Isoniazid goes straight into the intestines. This helps the prevention of the two drugs to interact and increases bioavailability of Rifampicin", he addd.
He said Rifampicin and Isoniazid are the drugs of choice of treating tuberculosis which has to be taken by the patient for six to nine months. World Health Organization (WHO) has sounded warning that only those formulations should be taken by the patient where bioavailability is assured.
TB affects around ten million people around the globe and India has the dubious distinction of having maximum number of people affected by TB. HIV/AIDS has only fuelled the presence of the disease.
"A novel formulation of these two anti-tubercular drugs is undergoing clinical trials at AIIMS Delhi for the past two years. Over 90 patients have been given the dose of the formulated capsule as well as the one available in the market. The results of the blind testing will be revealed by the end of the year", said Dr Navin Nivsarkar, director PERD centre.
DOTS program introduced by the WHO has not been successful in India. The dosage of the medication should be completed otherwise there are chances that the bacteria can relapse and can even develop multi drug resistant TB (MDR-TB), for which there is no treatment. "No new anti-tubercular drug has been discovered for the last 40 years. If we get a positive outcome after clinical tests, it will be a breakthrough in the cure for TB," added Prof Shishoo.
The Times of India