▁met abol ism ▁of ▁dru gs ▁as ▁well ▁as ▁other ▁studies ▁focused ▁on ▁ph arm ac ok inet ics ▁( PK ), ▁effic acy , ▁toler ability , ▁bio av ail ability , ▁and ▁safety . ▁The ▁introduction ▁of ▁de uter ated ▁drug ▁candidates ▁that ▁began ▁in ▁the ▁ 1 9 7 0 s ▁evol ved ▁from ▁earlier ▁work ▁with ▁de uter ated ▁met abol ites . ▁However , ▁it ▁took ▁more ▁than ▁ 4 0 ▁years ▁for ▁the ▁first ▁de uter ated ▁drug , ▁de ut etra ben azine , ▁to ▁be ▁approved ▁by ▁the ▁F DA . ▁N umer ous ▁publications ▁have ▁discussed ▁the ▁advantages ▁and ▁dis adv antages ▁of ▁de uter ated ▁dru gs ▁A ▁number ▁of ▁publications ▁have ▁discussed ▁aspects ▁of ▁intellectual ▁property ▁of ▁de uter ated ▁versions ▁of ▁dru gs . ▁ ▁Ex amples ▁▁ ▁De ut etra ben azine ▁is ▁a ▁de uter ated ▁version ▁of ▁t etra ben azine . ▁It ▁was ▁developed ▁by ▁Te va ▁and ▁approved ▁by ▁the ▁F DA ▁in ▁ 2 0 1 7 ▁as ▁a ▁treatment ▁for ▁Hun ting ton ' s ▁disease ; ▁it ▁has ▁a ▁longer ▁half ▁life ▁than ▁the ▁non - de uter ated ▁form ▁of ▁t etra ben azine , ▁which ▁had ▁been ▁approved ▁earlier ▁for ▁the ▁same ▁use . ▁ ▁Con cert ▁Ph arma ce ut ical s ▁focus es ▁on ▁de uter ated ▁dru gs ▁for ▁various ▁conditions . ▁ ▁The ▁company ▁Ret ro to pe ▁discovered ▁and ▁has ▁been ▁developing ▁a ▁de uter ated