The Intellectual Property Appellate Board dismissed the company's appeal against the ruling late on Tuesday.
The decision comes with Britain's second largest drugmaker battling sharply falling profits and the loss of patent protection on several of its biggest-selling drugs.
The setback for AstraZeneca, which could not be immediately reached for comment, was the latest to be suffered by a global drug conpany.
Earlier this year, an Indian ruling allowed a local firm to produce a vastly cheaper copy of German pharmaceutical giant Bayer's patented drug Nexavar for liver and kidney cancer.
Medical charities have expressed concern that compliance with WTO rules could reduce the country's role as a supplier of low-cost medicines. India is the world's leading exporter and manufacturer of non-branded medicines.
Western firms -- looking to countries such as India for sales growth -- have voiced criticism of brand protection in India.
India has some of the toughest criteria for drug companies to obtain patents, said DG Shah, secretary general of the Indian Pharmaceutical Alliance, an industry body.
"These rulings show (foreign) companies need to take into account that India will not permit tweaking of formulations for getting a patent. If they had those expectations, they were unrealistic," Shah told AFP recently.