The law of patents strictly adheres to a basic principle of balance between rights of patent holder and public interest. Patentability requires that patent is available for inventions whether product or process irrespective of different fields of technology. The three main criteria to be fulfilled is namely- novelty, inventive step and industrial application. Disclosure is an essential parameter to make a grant of patent on any invention. However, there has been a major change in the patent regime of India, the pharmaceutical industry has always been at the stage of advancement ever since. The Patents Act, 1970, introduced the concept of patent on manufacturing process initially. After the first amendment, India adopted system of transitional agreements. India is a signatory of both TRIPS and GATT. TRIPS introduced the concept of “product patent”, then after, in 2005, India started allowing patent on pharmaceutical drugs. A clear demarcation between patentable and non-patentable drugs has been made. The present paper will discuss about the evergreen strategies, the impact of various judicial interpretations on patentability of drugs manufactured by pharmaceutical companies and the change in the pharmaceutical patenting in India with the insertion of sec3 (d) which excluded the patenting of derivative pharmaceutical product on new forms of existing molecules and drugs.