Comparative Study of Antihypertensive Drugs Amlodipine Besylate /Metoprolol Succinate and Nebivolol Hydrochloride /Valsartan Combinations in Bilayer Tablets
The present research is an approach to develop a formulation platform that shall help in minimizing the time and effort taken to develop a drug delivery system. Taking bilayer tablet technology as a representation for drug delivery system, well accepted antihypertensive drugs, Amlodipine besylate and Metoprolol succinate were considered as model drugs for the study. Initially the process variables like concentration of the disintegrants, Sodium starch Glycolate and cross carmellose sodium, Polymers HPMC K100M and K4M were standardized with these drugs so that the incorporation of a new combination drugs would provide predictable results with a minimal trial runs. Nebivolol hydrochloride and Valsartan were considered as test drugs since they are novel antihypertensive drug combination and their physicochemical and pharmacokinetic parameters were almost similar to that of the model drugs. The r value 0.98943 indicates a good correlation between the release profile of Amlodipine besylate (model drug) and Nebivolol hydrochloride (test drug) from the IR layer. Similarly, the r value in the range of 0.9998 indicates a good correlation between the release profile of Metoprolol succinate (model drug) and Valsartan (test drug) from the SR layer. The comparable experimental results of the model drugs and test drugs considered for this study infer that if two drugs are similar in their physicochemical and pharmacokinetic parameters, their behavior with respect to in vitro parameters will be similar provided formulation variables remains constant. This concept could be productive in developing drug delivery system for new drugs for which extensive research and time are major constraints. Keywords: Bilayer tablets, fixed unit dosage form, Amlodipine besylate, Metoprolol Succinate Nebivolol hydrochloride, Valsartan.