ABSTRACT:
Bi-layer tablet is one of the new technologies for the successful development of controlled release formulations along with various features. Bi-layer tablet is suitable for sequential release of two different drugs in combination, separate the two incompatible substances and also suitable for the sustained release tablet in which one layer will be immediate release which serves as initial dose and second layer is maintenance dose. Nowadays the use of this bi-layered tablet technology has been enlarged. Bi-layer tablet is useful for gradual release of two active ingredients in combination. Two different incompatible drugs can also be formulated into a bi-layer tablet by adding an inert intermediate layer. Bi-layer tablets serves as one of the principle option to avoid chemical incompatibilities between the API’s which is mainly achieved by physical separation, and also helps to enable the progress of different drug release profiles (immediate release with extended release). In spite of their advantages, the mechanical structures of this drug delivery system have become quite difficult, requiring complicated tablet architectures due to the use of different materials and also the complex geometric boundaries. Bi-layer tablets provide specific advantages when compared to the conventional release formulation of the same drug. A number of pharmaceutical companies are now currently developing bi-layer tablets.