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Knowledge At MET

Knowledge At MET


An international regulatory requirement for registration of medicines prior to their sale has become a legal requirement. A generic product must comply with the standards established by Food and Drug Administration. The problems faced by generic drug companies were to carry out their own safety and efficacy studies associated with high costs and also the timing for US FDA approval for generic drugs. To overcome this, Drug Price Competition and Patent Term Restoration Act in 1984 was passed.

Scenario before HATCH-WAXMAN ACT: Prior to 1962 drugs were approved for safety & generic manufacturers were supposed to submit New Drug Applications on paper. (Paper-NDA: Approval by showing articles about the drug in official papers that it had been safe for use). Then Federal Food, Drug and Cosmetics Act (1962) was passed in which it was mandatory for generic drug manufacturers to perform clinical trials to prove their safety & efficacy equivalent to pre-established innovator drug product. After this FFDC Act, generic market crashed such that almost 150 drugs went off patent after 1962 but only 15 Paper-NDAs were filed. After this, HATCH-WAXMAN ACT was passed in 1984.


Use of bioequivalence as the base for approving generic drug products was established by “Drug Price Competition and Patent Term Restoration Act” of 1984, also known as the “HATCH-WAXMAN ACT”.


  • Increased availability of In 1984 - 12% prescriptions of generic, in 2000 - 44% and in 2003 - 51%.
  • Savings of $8- 10 Billions every
  • Average savings per prescription- approximately 53$.
  • 1% rise in generic prescription= $1.3 billion


The HWA created an abbreviated process for generic drug approval without conducting costly and duplicative clinical trials and by using bioequivalence as the basis for approval. The abbreviated New Drug Applications (ANDA) is submitted to the FDA’s Centre for Drug Evaluation or Office of Generic Drugs. It provides for the review and ultimate approval of a generic drug product. HWA can actually encourage generic drug companies to challenge weak patents. A generic company can be granted a period of market exclusivity of 180 days, provided that the generic company is first to file its ANDA along with Para IV certification.


ANDA has four types of submissions:

  • Para I: A Para I filing for the launch of generic drug is made when the innovator has not made the required information in Orange
  • Para II: A Para II filing is made when the drug is already off-patent.
  • Para III: A Para III filing is made when the applicant does not have any plans to sell the generic drug before the original drug is off-patent.

Para IV: A Para IV filing for the launch of generic drugs is made when the applicant believes its product or the use of its product does not infringe on the innovator’s patent or where the applicant believes such patents are not valid or enforceable.


Example of case study relating to Para IV filing Patent of PAXIL (Paroxetine HCl hemihydrates)

  • Smith-Kline Beckhem (SKB) obtained a patent of PAXIL as
  • In 1998 Apotex filed Para IV certificate for
  • SKB filed legal suit for patent
  • 30 months stay on Apotex approval as HWA
  • SKB filed patent extension for liquid oral dosage form of
  • 3 more patents in 1999 and 2000 for anhydrous
  • 5th patent for Paroxetine methanosulphate
  • Serial patent submission tactics, with newer 30 month stay every
  • Result: The patent of litigation expired but Apotex could never enter due to the newer

Recently in Nov’14 Supernus Pharmaceuticals sued Zydus for patent infringement of Trokendi XR. Zydus infringed 3 patents covering Trokendi. It contains anti-epileptic drug Topiramate which has patent protection till 2027.

By these incidents we conclude that although the HATCH-WAXMAN Act facilitated generic drug registration process, making it less costly & less time consuming by eliminating clinical trials, generic companies should also know how to launch the right drug in the right market at the right time.


Paris Suru, Mrinmayee Bhandari,

Shreya Mhatre (Final Year B.Pharm.)


Tags: MET Institute of Pharmacy