Tacrolimus Capsules are most commonly used after allogenic organ transplant for lowering the risk of rejection. They are immunosuppressive drugs that work by binding to interleukin-2 which is responsible for proliferation & development of T cells. These capsules are also indicated for treating T-cell mediated psoriasis & eczema. Tacrolimus has chemical formula C44H69NO12 with molar mass of 804.018 g/mol. They have hepatic metabolism which is assisted by CYP3A4 & CYP3A5 with elimination half life of 11.3 hours for the transplant. Tacrolimus Capsules have good protein binding ability of about 98.8% and are excreted mostly by the fecal route.