I recently bought a 1971 Upjohn Catalog, which lists all the products for sale in that year. I wondered what products in 1971 were still being sold by Pfizer 48 years later in 2019. Here are all the long-lived products:

Bacitracin Injection
Cleocin HCl Capsules
Cortef Tablets
Cytarabine Injection
Depo-Medrol Injection
Depo Provera Injection
Depo Estradiol Injection
Depo Testosterone Injection
Didrex Tablets
Gelfilm Absorbable Film
Gelfoam Absorbable Powder
Heparin Sodium Injection
Hydrocortisone Bulk Drug (API)
Hydrocortisone Acetate Bulk Drug (API)
Lincocin Injection
Medrol Tablets
Neomycin Sulfate Bulk Drug (API)
Penicillin G Procaine Sterile Suspension
Provera Tablets
Solu Cortef Sterile Powder for Injection
Solu Medrol Sterile Powder for Injection
Water for Injection

So there are 19 Upjohn products and 3 Upjohn bulk drugs available in 1971 still being sold by Pfizer in 2019. Impressively, none of these have any patent protection and most are being made at the Portage site!