Classification of Oral Controlled Drug Delivery Systems

Oral controlled drug delivery systems can be broadly divided into following categories, based on their mechanism of drug release:

1.    Dissolution-controlled release

a)   Encapsulation dissolution control

b)   Matrix dissolution control

2.    Diffusion-controlled release

a)   Reservoir devices

b)   Matrix devices

3.    Ion exchange resins

4.    Osmotically controlled release

5.    Gastroretentive system