| The bilayer tablet concept has long been utilized to developed sustained release formulations. Bilayer tablet has a fast
releasing layer and contain second layer to sustain the drug release. A fast releasing granules lead to sudden rise in the
blood concentration. However, the blood level is maintained at steady state as the drug release from the sustaining
granules. Bilayer tablet consist of two layers of tablet in a single unit. This approach can be used for the treatment of
various diseases which require not only single drug but also combination of drugs. Bi-layer tablet is suitable for sequential
release of two drugs in combination, separate two incompatible substances and also for sustained release tablet in which
one layer is immediate release as initial dose and second layer is maintenance dose. In which the one layer is formulated to
obtain immediate release of the drug, with the aim of reaching a high serum concentration in a short period of time. The
second layer is a controlled release, which is designed to maintain an effective plasma level for a prolonged period of time.
The pharmacokinetic advantage relies on the fact that drug release from fast releasing layer leads to a sudden rise in the
blood concentration. However, the blood level is maintained at steady state as the drug is released from the sustainingddd |
