Bilayer Tablet and Duredas Technology – a Review

The expense and complications in new drug entities have increased since last 3 decades, with concomitant recognition of the therapeutic advantages of controlled drug delivery. So focus has been given on development of sustained or controlled release drug delivery systems. Bilayer tablet is new novel of tablet for the successful development of controlled release formulation along with various features to provide a way of successful drug delivery system. For promoting patient convenience and compliance pharmaceutical industries interested in developing a combination of two or more API’s in a single dosage form. Bilayer tablet is improved beneficial technology to overcome the shortcoming of the single layered tablet. Bilayer tablets can be a primary option to avoid chemical incompatibilities between API by physical separation, and to enable the development of different drug release profiles using DUREDAS technology (immediate release with extended release/ both layer extended release). Despite their advantages, due to the use of different materials and complex geometric boundaries between the adjacent layers, the mechanical structures of this drug delivery system have become quite intricate, requiring complicated tablet architectures as well as patient-friendly. To reduce capital investment, quite often existing but modified tablet presses are used to develop and produce such tablets. This article explains why the development and production of quality bi-layer tablets needs to be carried out on purpose-built tablet presses to overcome common bi-layer problems, such as layer-separation, insufficient hardness, inaccurate individual layer weight control, cross-contamination between the layers, reduced yield, etc. Using a modified tablet press may therefore not be your best approach to producing a quality bi-layer tablet under GMP-conditions. Especially when in addition high production output is required.