Is it allowed to include substances in a patent that will not be used in the final product but have very similar characteristics to the one that is?

Question

Let's say i've made a new product for repelling lice and wish to patent it. Let's imagine that the active ingredient of this lice repelling product is ethanol. Ethanol is a member of the alcohol family which has other members such as Methanol, Propanol, Butanol and so on.

These substances share many similar characteristics with ethanol such as toxicity, solubility and flammability. Because of this there is a slight chance that some of these other alcohols could also be used in a product for repelling lice.

If that's the case then a competitor could potentially bring a similar lice repelling product to the market that is based on Methanol or Propanol instead and he would not be infringing on my patent.

To prevent this from happening I would want to file for a patent that gives me the exclusive right to not only use ethanol as the active ingredient but also any other alcohol that has similar lice-repelling characteristics as ethanol. Only ethanol would be used in the final product however. The other alcohols would merely be included in the patent to prevent someone else from creating a similar product using one of the other alcohols.

Would filing for a patent like that be allowed?

Answer 1

Yes. There is no legal requirement that an inventor produce a product in the market (or even intend to produce a product in the market) to obtain a patent.

To put it in the terms used in the question, you don't even have to produce the ethanol-based lice repellant, let alone all of the others.

With regard to stopping others from infringing a patent you own, that has become more difficult over time. It's more usual that a patent-holder is only able to recover some monetary damages from infringers. This applies particularly when the patent-holder is a so-called "non-practicing entity" (i.e., that has no competing product to offer to the market).

Answer 2

If you knew that a range of alcohols would be effective, then for sure you should try to claim as broadly as possible. You have to be novel and non-obvious and super broad claims might make that more difficult. However, the general philosophy is to claim as broadly as you can and narrow as needed to get the patent allowed. There is little reason, however, to claim something that doesn't work at all or so poorly as to be untenable as a product. You might also want to claim broader than just as a lice repellent and claim other insects or parasites if you can possibly support it.