Description and In silico ADME Studies of US-FDA Approved Drugs or Drugs under Clinical Trial which Violate the Lipinski’s Rule of 5

Background & Objective: Christopher A. Lipinski, in 1997, formulated Lipinski’s rule of five for drug-likeness prediction of potent molecules. It states that molecular weight (less than 500 Daltons), octanol/water partition coefficient (not exceeding more than 5), hydrogen bond acceptor (no more than 10), and hydrogen bond donor (no more than 5) are important for good oral bioavailability. Many drugs among various important classes such as antibiotics, anti-cancer, HIV and HCV protease inhibitors, immunosuppressants, cardiovascular, antifungal, and other miscellaneous classes are approved by FDA or other drug regulatory authorities as clinical use lie beyond the rule of five. In this review, beyond the rule of 5 drugs belonging to these classes (which are either currently approved or under clinical study) are explored and their ADME properties are analyzed. Methods: Data of 73 beyond the rule of 5 drugs, belonging to various classes, were collected and their ADME properties were calculated using the Qikprop prediction program of maestro 12.9 module of Schrodinger software. Results: Out of 73 drugs, 4 had at least 1 Rule of 5 (Ro5) violation, 16 had at least 2, 31 had at least 3 out of which 22 drugs had 4, Ro5 violations. Conclusion: Drugs not obeying the rule of five may also serve as good clinical candidates and potential candidates should not be discarded only on the basis of this rule.