OROS/GITS controlled-released tablets

When a GITS tablet enters a water-surrounding environment, surrounding water enters the drug core through semi-permeable membrane, causing the drug-containing layer partly dissolved or suspended in the water with an osmotic pressure, simultaneously, the push-layer absorbs water and starts to expand, as the result, the two forces combined push the drug out of the laser-drilled hole. The expanding of osmotic layer is the main force during drug release and with the steady and constant expanding of the osmotic layer results in a constant rate release of drug. Below is a diagram of the release concentration-time curve comparison between traditional tablet, extended release tablet and controlled release tablet.