ABSTRACT
The aim of present study was to improve dissolution rate of olanzapine by means of solid dispersion using combination of hydrophilic polymer (PEG & PVP) by using response surface design. Solid dispersion containing olanzapine were prepared using PEG 20000 & PVP K 30 by melted fusion method. Response surface method was used for the optimization olanzapine solid dispersions. Amount of PEG 20000 and Amount of PVP K 30 were selected as the critical process parameters (Independent variable) whereas amount dissolved in 10 minute (Q 10) and amount dissolved in 45 minute (Q 45) were selected as critical quality attributes (dependent variables). Optimized solid dispersion batch was characterized using infrared spectroscopy, differential scanning calorimetry (DSC) and X-ray diffractometry (XRD).Dissolution studies indicated a significant improvement in dissolution of olanzapine when dispersed in PEG 20000 and PVP k 30. XRD and DSC study indicated amorphous form of prepared solid dispersions. On the basis of numerical optimization technique, PEG 20000(X1) and amount of PVP K 30(X2) were 11.20 % and 14.53 % in optimized solid dispersion. The observed responses were closed well with the predicted values. The response surface method is found to be robust and accurate for optimization of solid dispersion for increase in solubility and dissolution rate of olanzapine, coherent with the needs of poorly water soluble drugs.