ABSTRACT

The objective of the work is to enhance the dissolution rate of poor water soluble antipsychotic agent clozapine by using hydrophilic carrier (mannitol). The dispersions were evaluated by phase solubility studies, drug content and in-vitro release studies. The optimized dispersions were further characterized by XRD, DSC, FT-IR, Near Infrared, Raman analysis and wettability studies. The phase solubility results and the thermodynamic parameters of the physical mixture indicated the spontaneity and solubilization effect of carrier. The in-vitro dissolution rate of cloza-pine from the dispersions was significantly better than pure clozapine. The release rate was found to increase up to an optimum drug: carrier ratio and then it tends to be constant with further increase in carrier content. XRD, DSC, Near infra red and Raman analysis indicated the crystallinity reduction and phase transition in clozapine. FT-IR analysis proved the compatibility between the drug and carrier. The wettability studies confirmed the increased wettability in samples. The possible reasons for increased release rate from solid dispersions were postulated and it was found to correlate well with the characterization findings.