Can I use Nokian's tire sealant to repair punctures in my existing tires?

I've got a question about using Nokian tire sealant to repair punctures in my existing tires. I've heard great things about this product, but want to make sure it's compatible with my current setup. Do I need to get new tires for the sealant to work properly, or can I just use it on my existing ones? Are there any specific types of tires that this won't be suitable for? Any advice would be greatly appreciated!