wow!!! i see very useful information over here , just add some more information here, regarding Indian Generic medicine please read , i just write for patient who cant differentiate the indian medicine.

Why India can produce and sell generic Harvoni?

Usually a drug such as Harvoni is patented and the originator (in this case Gilead Sciences) has an exclusivity on producing and selling the drug. However, even when Sovaldi came out in December 2013 in the US, India had problems with paying such a high price for a life-saving disease. Because India is such a big market with more than 1 billion people and estimated more than 30 million Hepatitis C patients, Gilead Sciences had agreed to give licences to India's pharmaceutical plants to produce and sell generic Harvoni and generic Sovaldi at a very low cost. On every sale, however, Gilead Sciences profits from royalties. Given that generic Harvoni is sold for around $10 per pill, if Gilead reaps $5 in royalties, there is still more than $10 billion to be made in India alone on Hepatitis C. In negotiations for this deal from which now every US or European Hepatitis C patient can benefit, it was stated by Indian authorities that they don't recognise the innovation that went into the development of Harvoni's active ingredient Sofosbuvir. Because the molecule is very similar to other antiviral drugs that already exist in the market, Gilead went on to give licences to produce generic Sovaldi at first, and when Harvoni came out in the US the licence to produce generic Harvoni followed.