Objective: The aim of the present study is to design oral fast-release tablets of nisoldipine and to optimize the drug dissolution profile by modifying the carrier concentration. Poloxamer 407 and Poloxamer 188 were selected as carriers for preparing the solid dispersion (SD) by solvent evaporation method with different drug polymer ratios. Methods: The prepared solid dispersions were analyzed for physical state, drug:carrier interactions by Xray diffraction, infrared spectroscopy, differential scanning calorimetry and scanning electron microscopy. Results: The dissolution studies revealed that all solid dispersions showed increased dissolution rate whencompared to pure nisoldipine. Among the two polymers used, poloxamer 407(P 407) was found to be better than poloxamer 188(P 188) in the enhancement of dissolution efficiency. The tablets were formulated using solid dispersion of nisoldipine containing poloxamer 407 as carrier. Conclusion: The results exhibited that poloxamer 407 SD based tablets gave a significantly higher release of nisoldipine when compared with control tablets. Infrared spectral studies showed that there was no interaction between thenisoldipine and its formulation with different carriers used in the preparation of solid dispersions. X-ray diffraction studies revealed that the degree of crystallinity of nisoldipine decreased when the concentration of carriers increased, which showed that the drug is in amorphous nature.
Key words: Fast dissolving tablets, Poloxamer 407, Poloxamer 188, Solid dispersion, Superdisintergrants.
