Preparation and Optimization of Quick/Slow-release Bilayered Tablets of Prazosin HCl using DoE and PCA

Abstract

The study aimed to develop once a day bilayer tablet of Prazosin HCl (PZH) for the effective treatment of hypertension with a quick-release layer to provide a loading dose while a slow-release layer as a maintenance dose. A statistical approach employing face-centred central composite design and principal component analysis (PCA) to develop bilayer tablets of PZH and scrutinize the critical responses was implemented. Independent factors in the study included the amount of guar gum (X1) and the amount of xanthan gum (X2). Results suggested the significant influence of independent factors on the dependent variables. Optimized formulation showed better performance with the initial first hour period giving a release burst from quick-release layer and then for the next 24 h a sustained release of drug follows. The drug release mechanism was analyzed using various mathematical models of which the optimized formulation exhibited the Higuchi Model. Accelerated stability studies of the preparation suggested no significant difference in the results even after six months. From the study, it could be concluded that a stable, once-a-day bilayer tablet preparation would be feasible in the context of patient compliance.