In the present investigation, solid dispersion of olanzapine has been prepared to improve its solubility. Further, using solid dispersion, mouth dissolving tablet was prepared to overcome the problem of swallowing. A Simplex Lattice design was applied using three factors, i.e. superdisintegrants like croscarmellose sodium(X1) crospovidone(X2), and sodium starch glycolate(X3) in tablet formulation. Disintegration time, Wetting time, Water absorption, T50 (Time required to 50% drug release) and Q10 (percentage of drug released in 10 min.) taken as responses. Solid dispersion showed significant enhancement in solubility of olanzapine. For mouth dissolving tablet, batch containing 5% croscarmellose sodium alone had minimum disintegration time (44 sec.) and faster drug release(T50: 40 sec) compared to other batches.