ABSTRACT:
Bi-layer tablet is a new era for successful development of controlled release formulation along with various features to provide successful drug delivery.Bi-layer tablet is suitable for sequential release of two drugs in combination and also for sustained release of tablet in which one layer is for immediate release as loading dose and second layer is maintenance dose. Bilayer tablet is best option for drug which have low bioavailablity and short plasma half life for formulating as a sustain release layer. Bi-layer tablets can be primary option to avoid chemical incompatibilities between APIs by physical separation and to enable the development of different drug release profiles.Several pharmaceutical companies are currently developing bi-layer tablets, for a variety of reasons: patent extension, therapeutic, marketing to name a few. So use of bi-layer tablets is a very different aspect for anti-hypertensive, diabetic, anti-inflammatory and analgesic drugs where combination therapy is often used.the present article provides an introduction to bi-layer tablet technology, need and general properties of bi-layer tablet dosage form, various techniques for bilayer tablets , bi-layer compression basics, manufacturing process of bilayer tablet, and recent developments in the field of bi-layer technology and finally evaluation of bilayer tablets.