Design, Formulation and Evaluation of Alpha Lipoic Acid and Metformin Bilayer Tablet Dosage Form
Abstract
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). The objective of the present study was to prepare the bilayer tablets of alpha lipoic acid incorporated as immediate release layer while metformin HCl as sustain release layer for the treatment of type II diabetes. The immediate release alpha lipoic acid layer was designed and optimized in the first step using crosscarmellose as superdisintegrant followed by sustained release layer of metformin HCl and optimized using 32 factorial design as well as compressed using 16-station double rotary tablet machine and evaluated. All the pre-compression and post-compression parameters were obtained within acceptable limits. Both the layers exhibited more than 85% drug release. Moreover, bilayer tablets were found stable as evident from drug content and drug release study. The bilayer tablets of alpha lipoic acid and metformin HCl with acceptable hardness, friability, drug content and more than 85% drug release were designed, prepared and evaluated.