Over the past three decades, focus is increased in field of sustained, controlled or delayed release drug delivery system because of their advantages over the conventional drug delivery system. The controlled release mechanism has entered a new era with the bilayer tablet. Bilayer tablet technology, which has a controlled release layer for maintenance doses and an immediate release layer for loading doses, aids in the separation of two incompatible substances. To release the medication at an interval other than just after delivery, a delayed-release dosage form is used. These tablets are used as advanced technique to subdue the problem of conventional single-layered tablet because they improved bioavailability of drug and fewer doses are needed. Bilayer tablets is an innovative formulation, which allow the controlled drug release, targeted delivery and combination therapies. They are mainly used to manage the chronic diseases, such as diabetes and hypertension. Many times, people with hypertension find it difficult or impossible to manage their blood pressure with just one medication or a drug. It has been shown that mono-therapy is very useful in treatment of patients with type 1 hypertension but it did not shown the desired therapeutic effects in some patients or with the type 2 hypertension patients, therefore combination of an antihypertensive drugs is required to achieve a desired therapeutics effects and the different drugs are combined to formulate a bilayer tablet for treating a hypertension. A combination of two or more antihypertensive drugs is significantly more successful or effective at lowering blood pressure than either one would be alone. This is due to the complementary types of action of the drugs. The introduction of techniques, advantages of the bilayer tablet, its components, and its benefits were the main topics of this review article. It also provided an explanation of the product quality.
Rajput et al. (Wed,) studied this question.