12 Disintegration test of all formulation was carried out in distilled Ku-0059436 clinical trial water by using United State Pharmacopoeia (USP) disintegrating test apparatus by following standard procedure. Tablets were crushed and powder transferred to 100 ml volumetric flask containing 40 ml of methanol. The flask was shaken to dissolve the drug and adjusted to the volume with methanol to obtain stock solution. Further suitable dilutions were done. The absorbance was recorded at λmax of 255 nm on UV spectrophotometer (Pharmaspec-1700, Shimadzu, Japan). The dissolution rates of all formulations were measured in dissolution test apparatus (Model Disso 2000,
Lab India) by Modulators tablet dissolution apparatus USP Type II. Dissolution studies were carried out using 900 ml PFT�� mw of 0.05 M phosphate buffer (pH 6.5) with 0.02% tween 20, as dissolution media, at 50 rpm and at temperature of 37 ± 0.5 °C. Appropriate
aliquots were withdrawn at suitable time interval (5, 10, 15, 20, 25, 30 40, 50, 60 min) and filtered through Whatman filter paper and diluted as per need with phosphate buffer pH 6.5. Sink conditions were maintained throughout the study.13 The samples were then analyzed at λmax of 255 nm by UV/visible spectrophotometer (Pharmaspec-1700, Shimadzu, Japan). The study was carried out in triplicate. As shown in Fig. 1 the saturation solubility of candesartan cilexetil increases in the order of glycerin < Span 80 < polyethylene glycol 400 < Tween 80. Solubility of candesartan cilexetil was significantly increased in presence of Tween 80 i.e. 200.54 mg/g. So tween 80 was selected as a non-volatile solvent in preparation of liquisolid compacts. Angle of repose were found to be in the Ketanserin range
of 29–39 indicating acceptable flow properties and this was further supported by lower compressibility index values (Table 3). Surface response graph of the angle repose [Fig. 2(A)] showing that, as drug: excipient ratio (R) liquid and drug concentration in liquid medication increases flow properties is improved. Regression values of X1 and X2 for angle of repose are as shown in Table 4. Formulation LS 7, LS 8, LS 9 has better flow property as compared to other formulation. The percent compressibility for all formulations lies within the range of 14.72 ± 2.475 to 21.76 ± 0.947. Hausner’s ratio was found to be in a range of 1.17 ± 0.03 to 1.27 ± 0.015 ( Table 3). IR spectrum of pure candesartan cilexetil (A) and liquisolid compacts (B) is shown in Fig. 3. The IR spectra of candesartan cilexetil exhibited distinctive peaks at 1080 cm−1 due to ethereal linkage stretching, 1752 cm−1 owing to – C O stretching of the carboxyl ion and at 1351 cm−1 because of C–N aromatic stretching.