ABSTRACT:
The enhancement in solubility and dissolution rate of poorly soluble drug Nifedipine was achieved by its adsorption on porous calcium silicate by using common volatile organic solvent chloroform. The yield of the adsorption process was found in a range of 90 -95% which indicates negligible loss during chloroform treatment. Saturation solubility studies showed 273% increase as compared to pure drug indicating adsorption of poorly soluble drug on porous calcium silicate was prominent in solubility enhancement. Physicochemical properties of pure Nifedipine compared to adsorbed product studied by FT-IR, DSC and PXRD. The FTIR and DSC studies does not show any unexpected interaction between Nifedipine and calcium silicate, while slight broadening in peak as well reduction in intensity and early onset as compared to the pure drug indicates adsorption of Nifedipine on porous calcium silicate. PXRD diffractograms showed a Significant reduction in peak intensities in drug adsorbed product compare to Nifedipine was attributed to the dilution effect of porous calcium silicate and confirms conversion of crystalline nature of drug in amorphous. Adsorption of the drug over FLR particles seen in SEM images of the adsorbed product while a significant change in surface morphology of Nifedipine was observed due to complete solubilization of Nifedipine and FLR in common solvent. The dissolution rate of the drug from adsorbed products was significantly rapid compared with pure drug, and the dissolution rate increases with increase in the proportion of FLR from 1:1.5 to 1:3, but further increase in the proportion of FLR not showed a significant increase in its dissolution indicating saturation. The drug adsorbed product was found stable as there was no any significant change in appearance and drug dissolution after three months stability studies.