ABSTRACT
Swelling and matrix are key systems in the field of drug delivery systems. However, these sys tems are differently identified in the pertinent literature. For instance, Peppas (1) used the term swelling-controlled release systems, Lee (2) named them as hydrogel matrices or polymeric matrices exhibiting moving boundaries. Lippold (3) adopted the physicochemical definition of hydrocolloid matrices, whereas Ford (4) proposed the pharmaceutical term hydrophilic matrix tablets. These systems can be appropriately referred to as swellable matrix tablets, considering that this definition contains the two key words of drug delivery systems, along with the indica tion of the pharmaceutical manufacturing procedure.
