ABSTRACT:
Novel technologies with improved performance, patient compliance and enhanced quality have emerged in the recent years. The expense and complications involved in marketing new drug entities have increased with concomitant recognition of the therapeutic advantages of controlled drug delivery, greater attention has been focused on development of sustained or controlled delivery systems. The introduction of bilayer tablets into the pharmaceutical industry has enabled the development of pre-determined release profiles of active ingredients and incorporation of incompatible active ingredients into the single unit dosage form. Bilayer tablet is improved beneficial technology to overcome the short coming of the single layered tablet. The good quality bilayer tablet production needs to be carried out on specially designed presses to overcome the common problems like layer separation, insufficient hardness, inaccurate individual layer weight control, cross contamination between the layers, reduced yield etc. Nowadays the pharmaceutical companies are currently developing bi-layer tablets due to variety of reasons such as patent extension, therapeutic benefit and a marketing strategy. To reduce capital investment, quite often existing but modified tablet presses are used to develop and produce such tablets. Large number of work has been done in this field. Some of the recent findings are explained in the preceding review article.