The invention relates to the field of pharmaceutical compositions. More particularly it is directed to substance delivery system (or implant) such as scaffolds and membranes comprising an anabolic drug such as a Fibroblast Growth Factor 18 (FGF 18) compound to methods of producing such delivery system as well as use thereof. The implants according to the invention are for use for the treatment of cartilage disorders such as osteoarthritis cartilage injury or osteochondral defects