Formulation of liquisolid tablets of candesartan cilexetil

Abstract

The main objective of present investigation was to enhance the dissolution rate of water insoluble drug Candesartan cilexetil by using liquisolid technique. Liquisolid tablets were prepared using a mathematical model to calculate the required quantities of carrier and coating materials to produce acceptably flowable and compressible admixture. Propylene glycol, PEG 400, Cremophor EL, Capryol 90 and Tween 80 were used as non-volatile liquid vehicles. Avicel PH 102, Aerosil 200 and sodium starch glycolate were employed as carrier, coating material and disintegrant respectively. Drug concentration of 20% w/w (1:4 ratio of drug and liquid vehicle) and 40% w/w (1:2 ratio of drug and liquid vehicle) and R-values (carrier to coating materials ratio) of 10, 20 and 30 were used to formulate the tablets. The formulated liquisolid tablets were evaluated for various parameters including dissolution studies. It was found that the liquisolid tablets formulated with Cremophor EL at drug concentration of 20 % w/w showed higher dissolution profile when compared with other liquisolid formulations, pure drug and directly compressed tablets. The stability studies showed that the dissolution profiles of liquisolid tablets were not affected by ageing significantly. Infrared spectroscopic (IR) and Differential Scanning Calorimetric studies confirmed no interaction exists between drug and excipients. Powder X- ray diffraction studies (PXRD) suggested loss of drug crystallinity upon liquisolid formulation which was further confirmed by scanning electron microscopy (SEM).