Solid Dispersion- A way to Enhance Solubility of Quetiapine Fumarate

Quetiapine Fumarate is a antipsychotic agent indicated for treatment of Schizophrenia and Bipolar disorder. Quetiapine Fumarate is BCS Class II drug which is  poorly water soluble and may show dissolution limited absorption. Hence to improve dissolution rate and bioavailability, Solid dispersion of Quetiapine Fumarate by Solvent Evaporation method were prepared using 1:1, 1:2, 1:3, 1:4 and 1:5 ratios of Quetiapine Fumarate and Polyvinyl Pyrrolidone K30(PVP K30). The solid dispersion (SD) was characterized for physical appearance, solubility, FTIR, DSC, XRD studies and in vitro dissolution studies. FTIR study revealed that there was no drug-carrier chemical interaction in Solid dispersion. DSC studies revealed that, the peak observed for the melting of Quetiapine Fumarate is found to be absent in SD with PVP K30 carrier. XRD studies suggested that there has been a large change in the nature of Quetiapine Fumarate in the solid dispersion. Solubility of Quetiapine Fumarate from SD increased in distilled water. The drug content was found to be high and uniformly distributed in the formulation. The in vitro dissolution studies were carried using USP type II (paddle) type dissolution apparatus. The prepared Solid dispersion showed marked increase in the dissolution rate of Quetiapine Fumarate than that of pure drug. The Solid dispersion with PVP K30 (1:5) by Solvent evaporation method showed faster dissolution rate as compared to other Solid dispersions. It is concluded that dissolution of the Quetiapine Fumarate could be improved by the Solid dispersion.