A REVIEW ON BILAYER TECHNOLOGY

ABSTRACT Over the past 30 years, the expenses and complications involved in marketing new drug entities have increased with concomitant recognition of therapeutic advantages of controlled drug delivery. Now a days greater attention has been focused on development of controlled & immediate release drug delivery systems. 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. 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. Several pharmaceutical companies are currently developing bi-layer tablets, for a variety of reasons: patent extension, efficient pharmacological effect, better patient compliance etc. Bi-layer tablet is suitable for sequential release of two drugs in combination and/or to incorporate two incompatible substances in same tablet. This approach can be utilized for fabrication of sustained release dosage form (tablet) consisting of outer immediate and inner layer as a maintenance dose. To overcome the short comings of single layered tablet approach like bilayered tablet (immediate and sustained release) can be satisfactorily used. This review explains fundamentals of bilayer tablet system along with its fabrication techniques, different approaches, characterization, challenges in Bilayer tablet manufacturing, Quality & GMP requirements, for their production and recent developments in the field of bilayer technology. Present review mainly focuses on fundamentals of bilayer tablets and it’s applications in Pharmaceutical industries KEYWORDS: Bilayer tablet Sustained release, Immediate release, GMP requirement