What are the best way to search closest prior art and how to identify closest prior arts from prosecution file history for pharmaceutical patents.

3 Answers 3


What are the best way to search closest prior art

Too broad to specify it depends on how well are keywords designed. If you are referring to searching a prior art for specific patent application then following are methods generally used to get documents:-

  1. Browse documents using all classes listed in respective patent
  2. Further limit is using inventive feature synonyms.
  3. Use alternative language like German and Korean etc this is useful for NPL.

how to identify closest prior arts from prosecution file history for pharmaceutical patents.

apart from above methods

  1. Use ISR or examination report documents as base, design keywords based on abstract of same.
  2. review search strategy used by USPTO examiner to see if any loopholes present.
  3. Pool all ISR and applicant cited documents and use forward and reverse citation on them.
  4. Check all examination reports of subject Patent family.
  5. Use IDS document as additional source.
  6. Pay special attention to examiner cited documents and review cited documents prosecution history for NPL and additional documents.
  7. Pay special attention to abandoned applications for prior claiming.

Searching prior art is something like finding a needle in a haystack. It depends on the keywords you're focusing and how well are you in searching (experience actually).

What are the best way to search closest prior art

The methods also depend on whether you are performing a novelty search for an invention or doing a prior art search for invalidation.

This isn't hard if you have done any prior art search before. Traditionally prior art searches start from keyword creation. You can go a little broader with the subject of your patent and keywords based on that.

for example, If your invention is related to Li-Fi; you can use similar to following keywords - "VLC", "Visible Light Communication", "optical communication" and the like.

Then comes the searching, as of my knowledge basic searches starts from patent databases like Thompson or Orbit. You pull out a massive set of patents based on your keywords and then refine narrow down data after examining classes and deeper keywords.

After going through patent databases, you can search in NPL(non-patent literature) using your keyword set. Go through search engines, blogs, and even research papers.

This is just a wireframe of the process, it's a little more complex. Hence, consider this answer as a walkthrough.

Similar process goes on when you perform an invalidity search. This time, you have a patent to start from. Very first step is going through citations and references and listing down the classes. Then creating keywords based on the same.

There's another aspect which is usually missed by many experts, and that is prior art searching in non-textual data. i.e. Images and Videos.

Here I have a great example of the same - Apple's rubber banding effect patent was invalidated in Germany due to existing prior art. The prior art was found in Steve Jobs's keynote video on iPhone launch, where he publically revealed the feature. This is why you should also focus on non-textual data while searching for prior art.

Few cases where prior art was found in non-textual data - 4 CASES WHERE EXAMINER FOUND RIDICULOUSLY AWESOME PRIOR ART

Also, if you want to learn more about prior art search here are few articles I recommend. I found them extremely helpful for me -


if you want to search patent, key words and classification number(such as,IC,CPC,UC) is the most effictive way to get the prior art.

  • Answers to old questions are encouraged if they add something significant beyond existing answers. This answer is very generic about searching and not addressed to the specifics of the question.
    – George White
    Commented Dec 6, 2023 at 23:06

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .