As technologies for monitoring health parameters get closer to our body, and sometimes can even get embedded in our body, also drug delivery methods are making progress in the direction of embedding the "dispenser".
There are already on the market insulin pumps that people with diabetes can wear on their belt having a tiny plastic the that is positioned under the skin to deliver tiny amounts of insulin when needed, there are microchips that can deliver several drugs based on a programmed cycle, there are drug dispensers that a surgeon implants at the end of a surgery to control post operative pain by releasing tiny amount of drugs through a catheter connected to the spinal cord.
All these implantable technologies are progressing and it will become common place by the end of this decade.
There are also drugs that can be implanted under skin to slowly release the substance (most used are those to prevent pregnancy) and researchers are studying new materials that would make it possible to dispense medical substances at predetermined and changeable rates.
Researchers at MIT have shown how to build a hydrogel that can be injected using a normal syringe having the property of retaking a specific shape once injected. The gel is made by nanoparticles made of polymers entwined with a different type of polymer. This mixed composition has been designed to let the gel be compressed into a needle for injection and then reacquiring the desired shape once injected.
The idea is that the doctor can program the desired shape, the one best fitting the release of a drug in a specific area, and inject it without having to use a scalpel (surgery). The polymer structure can be "loaded" by two different drugs that in turns can be programmed for cycles of releases depending on the need. The "programming" is actually the result of the polymer structure.
Amazing the idea of having material structure working as "programs". This is one of the aspects of smart materials, a game changer technology for the next decade.