Bi-Layer Tablets: An Emerging State of Art Technology in Dosage Form Design

Despite significant advancements in dosage form design, oral route still remains the most favoured route of drug administration. Even now-a-days tablets have got more attention compared to other dosage forms because of simple, inexpensive, greater stability and most suitable nature of tablets. More recently major considerations in tablet sector have been focused on development of controlled and immediate release drug delivery systems. Many pharmaceutical manufacturers are giving more emphasis to bi-layer tablet sector now a day, because of several advantages like extension of patent, improved therapeutic response, enhanced patient compliance etc. Bi-layer tablet is a new era for the successful development of controlled release formulation along with various features to provide a way of successful drug delivery system. These can release more than two drugs in combination chronologically. Two incompatible substances can be remaining separated from one another in a single tablet. They can provide a biphasic release with one immediate release layer to produce the loading dose and second layer is maintenance dose in order to achieve the immediate pharmacological response lasting for a prolonged period. Current review especially emphasizes on the rationale, various approaches for designing of the bi-layer tablets including patented techniques, types of tablet presses, quality and GMP considerations, advancement sin the field of bi-layer tablet technology, troubleshooting problems in the preparation of bi-layer tablets etc