Total revenue reached $1.5bn (€1.1bn) for the company, one of India's top three pharmaceutical manufacturers, which was up from $563m for the year before. Substantial growth in the international market showed a massive 250 per cent increase from the previous year compared to an 11 per cent increase in revenue from India alone. While India was the largest market source in the 2005 year for the company, it was replaced in 2006 by North America, which now contributes 44 per cent to the revenue, reflecting a 611 per cent increase. This change reflected an increased growth in all areas. Europe also showed a significant increase in its market position, moving into second place after North America and contributing 23 per cent to total revenue. Authorised generics and acquisitions, such as that of Betapharm in Germany in March last year, played a strong role in the growth with authorised generics and acquisitions contributing 24 per cent and 21 per cent respectively to the total revenue. Revenue from APIs increased by 44 per cent to $276m and contributed 18 per cent to the total revenue, primarily driven by sales of sertraline, rabeprazole and ramipril. APIs showed a strong increase in the international market (64 per cent), but this was matched with a 10 per cent decline in the Indian API market because of a decrease in sales of quinolones resulting from a decline in prices. Dr Reddy's filed 23 drug master files (DMFs) in the US in 2006-07. The company also filed 11 DMFs in Canada, nine DMFs in Europe, six DMFs in Japan and five in Turkey. It also has 69 abbreviated new drug applications (ANDAs) pending with the US Food and Drug Administration (FDA) addressing innovator sales of $57bn. Dr Reddy received 19 approvals, including tentative approvals, last year. India is a hub of generic drug production, already producing 22 per cent of the world's generic drugs, and the industry there has begun to challenge US drug patents. Dr Reddy's reported it has filed 33 patent challenges in US courts. Earlier this month Dr Reddy's started distributing Reditux in India, which is a generic version of Rituxan, a non-Hodgkin's lymphoma treatment developed by US-based Biogen Idec. The generic version is selling for half the price of its branded counterpart. Dr Reddy could have approval to distribute the generic version in the US after the patent expires in 2015, according to analysts. In December last year, the company began selling ondansetron, its generic version of GlaxoSmithKline's anti-nausea drug Zofran. It has 180 days to sell the drug without generic competition. Meanwhile, Dr Reddy's already makes generics of Bayer's Cipro (ciprofloxacin) and Merck's Zocar (simvastatin) and is likely to go after Pfizer's Norvasc (amlodipine besylate) hypertension drug (which already has Mylan and Pfizer generics) and Glaxo's Coreg (carvedilol) heart disease treatment when their patents expire later this year.