Design, In Vitro Evaluation of Sustained Release Matrix Tablet of Enalapril Maleate Employing Natural Polymer-Olibanum Gum and Its Resin Component

In order to offer a sustained release of tablets containing Enalapril Maleate by employing olibanum gum were tested as matrix components that could control release rate. Enalapril was chosen due to its short half-life and limited oral bioavailability (41%). In order to confirm the chemical interaction between drugs and polymers, FTIR and DSC investigation was conducted. Matrix tablet of Enalapril Maleate was formulated using varied concentrations of HPMC K 100 M, olibanum, its resin, and its carbohydrate component. The tablet was evaluated for pre-and post-compression studies. Within low concentrations ranging from one to 2% w/w, the resinous component of olibanum and olibanum gum has a retarding effect on release rate of drug from matrix tablets. Enalapril Maleate was released slowly and systematically over a period of more than 24 h by Enalapril Maleate matrix tablets formulated with olibanum and its resin component. Release rate and % polymer relation was found to be linear in each case. Enalapril Maleate matrix tablet exhibited good controlled release characteristics and found suitable for once, a day oral controlled release products.