Abstract
The main objective of the present study is to study the rate controlling efficiency and release retarding efficiency of olibanum gum – a natural polymer obtained from Boswellia serrata, Roxburgh and other species of Boswellia. Captopril is an antihypertensive drug and has a half life of 2hrs and requires a daily dose of 37.5-75 mg to be taken three times. So, a controlled release form is required. Floating tablets of Captopril (25mg) were prepared employing olibanum as matrix former , sodium bicarbonate, tartaric acid as gas generating agent and HPMC K4M as floating enhancers by direct compression method and the tablets F1 to F8 were formulated with varied proportions of olibanum gum. The formulations were evaluated for various pre compression, post compression parameters, floating and drug release characteristics. All the prepared formulations were of good quality. Formulation (F7) exhibited a floating time of more than 8 hours and with a floating lag time less than 70sec and provided slow and complete release of Captopril over 12 hours. Release was diffusion controlled and followed zero order kinetics. Non – Fickian diffusion was the release mechanism from all the floating tablets formulated. FTIR studies reports indicate no interaction between drug and polymer. Hence Olibanum gum was found suitable as release retarding polymer for better controlled release of Captopril over a period of 12h and also cost effective.
