NOVEL FORMULATION AND ANALYTICAL EVALUATION OF BI-LAYERED TABLETS OF ENALAPRIL MALEATE, HYDROCHLOROTHIAZIDE AND NIFEDIPINE

The present research is intended for the formulation development, optimization, and in-vitro evaluation of bi-layer tablets containing Enalapril maleate, hydrochlorothiazide in the immediate release layer and Nifedipine in the sustained release layer based on GEMINEX technology. The impact of formulation variables such as combination of polymers and coating solution on the drug release was evaluated from the developed formulation. The prepared formulation blend was assessed for compressibility characteristics. The homogeneity of each API in a blend was tested by determining the %assay of individual drugs from different layers. Both the immediate and controlled release granules were formulated into bilayer tablets by the direct compression method. SEM analysis of bi-layered tablets was also performed. The mean drug content for all formulations was found to be within specified limits. The In-vitro dissolution studies can be performed at USP type II dissolution apparatus for coated tablets. The release of Enalapril maleate and hydrochlorothiazide from the immediate-release layer was found to be 99.2+0.8% and 99.5+1.1, and Nifedipine from the sustained release layer was found to be 100.7%+0.5%, respectively. Hence the bilayer tablets of Enalapril maleate Hydrochlorothiazide and Nifedipine were used to improve patient compliance towards the effective management of hypertension.