Characterization of olanzapine-solid dispersions

To enhance the aqueous solubility of olanzapine by using the Solid dispersion technique. Solid dispersions of olanzapine were prepared by the dispersion method using using PGS and SSG as carriers. Drug-carrier ratios such as 1 : 1, 1 : 2, 1 : 4, 1 : 6, 1: 8 and 1 : 10 were tried for optimization. Characterization was done by phase solubility, in-vitro release, saturation solubility, permeation, wettability, XRD and FTIR analysis. Solid dispersions showed higher solubility and an improved drug release profile than the pure drug. Solid dispersion and physical mixture with a drug-polymer ratio of 1 : 10 showed the best release profile in comparison with the other samples. Phase solubility results verified the solubilization effect of the carrier. XRD and NIR analysis confirmed the reduction of crystallinity in the samples. The release study findings were well supported by the results of wettability, saturation solubility and permeability studies. IR analysis substantiated the inertness of the carrier. It was concluded that pregelatinised starch (PGS) and sodium starch glycollate (SSG) could be utilized as effective carriers to improve the aqueous solubility of poorly soluble drugs.