The use of the regular cards is governed by the same policy as regular tweets i.e. if it’s OK on Twitter then it’s OK in cards. However, if you are using the product cards to essentially advertise then you’re still going to end up in the ads category, even if you’re not using the paid / promoted Twitter Ads. With that in mind I’d suggest that you follow the ad guidelines for your specific pharma products and the UK (or any other target market) to avoid any issues.
Thanks for being thoughtful enough to ask the question!