Wiktionary
timed-release
a. that releases its active ingredients gradually, so as to produce a sustained effect
Usage examples of "timed-release".
The murky suspension of Keylate that Americans swallowed contained not only the selective chelates, but coated particles of replacement elements which, like tiny timed-release caps, became available to the body only after chelates had removed newly-absorbed elements.
Or, better yet, planted some exotic disease cultures in timed-release capsules in his gluteal muscle sheath.