Formulation and Evaluation of Bilayer Tablet of Amlodipine and Metoprolol in the Treatment of Hypertension

The current work focuses on the development and evaluation of bilayer tablet of Amlodipine & Metoprolol in the treatment of hypertension. The release of Amlodipine and Metoprolol was controlled by formulating it into a immediate and sustained release layer respectively. The formulae was developed using various individual concentrations of crospovidone and various individual concentrations and viscosity grades of HPMC polymers for both immediate and sustained release layers respectively . The compatibility of polymers and excipients along with pure drugs was evaluated using FTIR studies. The tablets were prepared and Pre- and Post-compression parameters, In-vitro dissolution testing, release rate kinetics and stability studies were evaluated. The FTIR spectra’s confirms the absence of chemical interaction between drug and polymers. All the Pre and post-compression parameters were found to be in limits. From the results of dissolution testing it was found that the batches IRL-4 and SRL-12 were found to be best of all the immediate and sustained release layer batches respectively. Thus they both were compressed to get a novel bilayer tablet formulation. The data for stability studies revealed that no considerable differences in drug content and dissolution rates for a period of 6 months as per ICH guidelines. Thus, a novel bilayer tablet formulation of Amlodipine and Metoprolol were successfully developed by combining both immediate and sustained release layers.