Taxol, an effective
anti-cancer drug that was approved for use in
the US last year, will soon be available in India at half the cost
The Dabur laboratary where tax CAPITALISING
on more than 100 years of expertise in plant product chemistry, Dabur,
one of India's largest Ayurvedic formulation manufacturers, has now
ventured into modern pharmaceutical research and product development.
Dabur recently announced that it had perfected a method to extract taxol
-- a potent drug used to treat ovarian and breast cancers -- from the
leaves of the Himalayan yew (
Taxus baccata).
Says Anand Burman, director of research and development at Dabur, "We
cannot compete with the big players in the synthetic pharmaceutical
business, so we are limiting our efforts to what we know best -- natural
plant products and extracts."
Though discovered in the early 1960s, taxol was cleared for use in
the US only in January 1993 after evaluating the side-effects of the
extract and the solvent used to administer it. Also, extracting taxol is
extremely difficult and expensive.
Taxol was first extracted in minute quantities from the bark of the Pacific yew (Taxus brevifolia),
but Dabur succeeded in obtaining it from the leaves of the Himalayan
yew. The Dabur drug has been sent for pre-marketing clinical trials to
Ganga Ram Hospital in Delhi, the Apollo Cancer Hospital in Madras and
the Tata Memorial Hospital in Bombay. Says an excited P S Srinivasan,
general manager at Dabur, "For the first time, a drug will be released
in the Indian market soon after it has been introduced abroad."
The drug Dabur plans to sell in India will cost about half of what it
does abroad because it is cheaper to extract taxol from leaves than
bark. Also, higher quantities of taxol can be extracted from leaves. A
patient requires about 8 courses of the drug -- a total of about 1.7 gm
of taxol -- and according to Burman, this would cost almost Rs 3 lakh
abroad.
Dabur has already invested Rs 11.5 crore in the taxol project, of
which about Rs 4 crore is in research alone. The Rs 7.5 crore plant set
up at Sahibabad has a capacity to produce about 600 gm of taxol a month.
They eventually hope to raise production to about 2 kg per month.
Dabur reckons only about 3,000 patients in India will need the drug
every year. It plans to export the drug after obtaining a worldwide
patent on the extraction process.
Scientists at the Dabur Research Foundation have not only managed to
extract taxol, they have also been able to obtain fairly large amounts
of a taxol intermediate called baccatin. Converting the baccatin to
taxol, using chemicals, has been achieved only at a laboratory scale
yet.
Dabur scientists claim that their process of extracting taxol --
using various solvents and sophisticated separation equipment -- from
leaves is far less destructive to the tree and the environment than
deriving it from the bark. Once the bark is stripped off, the tree
usually dries up and dies.
However, the Himachal Pradesh-based Himalaya Nature and Environment
Preservation Society has protested against Dabur's exploitation of yew
leaves from forests in the state. According to a forestry expert
associated with the society, Dabur hired contractors to lop off entire
branches of the tree, affecting the health of the slow-growing conifer.
Moreover, the society contends the royalty paid to the forest department
is meagre and only a little of it reaches the local people.
Dabur claims it is conscious of the need to conserve the yew. It is
to initiate a project to identify varieties of yew that have high taxol
content and to propagate them using tissue culture techniques. They also
plan to set up yew plantations in Uttar Pradesh and Nepal.
