[sloppycee]

Concerta ER does something like that, I'm curious why it isn't more widely used.

"The system, which resembles a conventional tablet in appearance, comprises an osmotically active trilayer core surrounded by a semipermeable membrane with an immediate-release drug overcoat.

The trilayer core is composed of two drug layers containing the drug and excipients, and a push layer containing osmotically active components. There is a precision-laser drilled orifice on the drug-layer end of the tablet.

In an aqueous environment, such as the gastrointestinal tract, the drug overcoat dissolves within one hour, providing an initial dose of methylphenidate. Water permeates through the membrane into the tablet core. As the osmotically active polymer excipients expand, methylphenidate is released through the orifice. The membrane controls the rate at which water enters the tablet core, which in turn controls drug delivery."

[warsharks]

in terms of ADHD Vyvanse/Elvanse/Lisdexamphetamine is more interesting in my opinion, its dexamphetamine bound to lysene. your body naturally strips the lysene away releasing the dexamphetamine over a period of 12 hours.

it doesnt rely on being mixed with something to delay its action or be pressed into a solid pill, in fact you can open up the capsules and eat the powder inside and there is no change in its effects (its also ineffective intranasally or as far as i am aware even if injected) its rate of release is difficult to change, its just how long the average body takes to strip the lysene away from the chemical.