Abstract:
The effects of compositions and spray drying conditions on dissolution rate enhancement of poorly soluble drug indomethacin (IMC) were investigated in this study. Solid dispersion between IMC and beta cyclodextrin (BCD) at molar ratios of 2:1, 1:1 and 1:2 in phosphate buffer pH 7.4 and IMC and sodium lauryl sulfate (SLS) at concentrations of 13%, 20%, 27% and 33% w/w in phosphate buffer pH 7.4 were prepared by various spray drying conditions. The products were characterized by scanning electron microscopy (SEM), powder X-ray diffractometry (PXRD), differential scanning calorimetry (DSC) and Fourier transform infrared (FTIR) spectrometry. Chemical interactions between IMC and BCD were found during the spray drying process. Solubility study and dissolution rate study of spray dried IMC/BCD suggested that there were significant solubility and dissolution rate increase with spray drying process compared to pure IMC, spray dried IMC and its physical mixtures. The spray drying conditions, such as inlet air temperatures (130,140 and 150 °C) and feed rates (10, 15 and 20 ml/min), however, were not shown to have significant effect on the solubility and initial dissolution rates. Moreover, High Performance Liquid Chromatography (HPLC) study showed that the addition of BCD in the spray dried powder of IMC/BCD retarded the degradation process of IMC during spray drying. The solubility and initial dissolution rate of spray dried IMC/ SLS were higher than pure IMC, spray dried IMC and its physical mixtures. HPLC study showed that the degradation of IMC was accelerated by the spray drying process with SLS.
