ENHANCEMENT OF DISSOLUTION RATE OF ZALEPLON BY SOLID DISPERSION TECHNOLOGY USING HYDROPHILIC POLYMERS AND SOLID STATE CHARACTERIZATION

Objective: Enhancement of dissolution rate of zaleplon by solid dispersion technology using hydrophilic polymers and solid state characterization & dissolution behavior Methods: Formulation parameters by the solvent evaporation method at different drug: polymer ratios Results: The results showed that PEG 6000-based solid dispersion exhibited significantly higher zaleplon dissolution. zaleplon has high melting point, which is indicative of strong crystal lattice energy. All solid dispersions of zaleplon prepared with PEG 6000 and poloxamer 407 polymers showed enhanced drug solubility over the pure zaleplon (0.11) mg/ml in distilled water and (0.23)mg/ml in phosphate buffer 6.8. The in vitro release studies were carried out for the zaleplon solid dispersions prepared by melting method. The dissolution rate of pure zaleplon was very poor and during 120 min a maximum about 28.55% of the drug was released. Pure zaleplon exhibit a peak at 187.52 °C which represent the melting point of zaleplon. DSC curve of PEG 6000 showed a peak at 64.34°C and poloxamer 407 showed peak at 58.67°C The patterns of the poloxamer 407 and PEG 6000 also showed few peaks indicating its crystallinity nature. Conclusion: The formulation of solid dispersion of a drug with hydrophilic crriers is a potential approach used to improve the solubility and dissolution rate of practically water insoluble or less soluble drugs.