Controlled release of a particular drug is required in some patient to achieve optimum therapeutic action, which can be achieved by
1) Sustained drug delivery tablets.
2) Delayed drug delivery tablets.
3) Osmoticaly Controlled Tablets dosage form
When only drug release is to be sustained for long period of time a matrix system that holds drug and releases in steady pattern from its matrix by osmosis, dissolution is adapted. HPMC and CMC polymers dispersed are formed.
Osmotic tablets technology:
1) Tablets are coated with a semi pemiable membrane and a small hole is drilled on one surface of the tablet. Hole on tablet surface is drilled with the help of lesser beam. One can control the size of the hole of surface of table by considering the rate of drug dissolution and permeation through the hole.
2) asymmetric-membrane technology (AMT) : In this technology a micro porous membrane coating is done on the tablets which when administered release drug after sweeling of this membrane is achieved, drug release is almost zero order and steady.
3) osmotic swellable core technology (SCT): This type of tablets are coated with semipermiable coating, tablet consist of two layers, 1) one layer of drug molecule, on the face of which a small hole is drilled. 2) A swellable polymer when comes in contact with water swells and create a pressure inside table pushing other layer of drug to release from the lesser drilled pore.
These type of tablets have wide range drug delivery pattern, by choosing a best fit swelling polymer and controlling the size of lesser drilled pore on tablet.
Drug release from these type of tablets is steady and almost can be comparable with in vivo to invitro results of dissolution and absorption of drug molecule.
Laser drilling on tablets can be achieved by machines available which make use of round turret and a tablet pass under lesser beam where in a hole is drilled, before drilling hole machine have a sensor for detecting correct face for drilling hole on tablet coat. Further inspection on camera is done for tablets to ensure the same.