Office of Grand Ayatollah Makarem Shirazi (may Allah grant him long life):
If you are certain that they contain pork ingredients, buying and selling of them are a matter of objection.
Office of Grand Ayatollah Saafi Gulpaigani (may Allah grant him long life):
I have no information about what those things in the question are made of. However, if what you have written in your mail is true with the products, it is not permissible to buy and sell them, though the customers might be non-Muslims. And if you entertain doubt about the ingredients of the capsules, it is not necessary to investigate.
Ayatollah Mahdi Hadavi Tehrani (may Allah grant him long life) has replied to the foregoing question as under:
1. As for the components of the capsules, you should refer to pharmacists [to tell you what they are extracted from].
2. If something consists of pork extracts, it is impure and forbidden to eat, and it is also not permissible to sell it to Muslims but selling them to those (non-Muslims like Christians) who consider pork to be halal is permissible.