Crystalline form of lamotrigine hydrate, method for preparing the same and composition comprising the same

A method for preparing lamotrigine hydrate form A in a suspension, comprising the steps of:

• adding lamotrigine particles and a thickener to an aqueous phase;
• dispersing the lamotrigine particles having a particle size (D90) ranging from about 8 to about 12 μm and the thickener uniformly in the aqueous phase;
• and cooling the aqueous phase at a temperature lower than 25° C. to obtain the suspension comprising the lamotrigine hydrate form A, wherein the form A has a particle size ranging from about 20 to about 30 μm in the suspension, wherein the term about indicates a range within ±1 of a given value,
• wherein an XRPD spectrum of the lamotrigine hydrate form A comprises characteristic peaks at diffraction angles (2θ) of about 11.5±0.2°, 13.4±0.2°, 15.0±0.2°, 16.5±0.2°, 19.2±0.2°, 26.9±0.2° and 27.7±0.2°, and has no characteristic peaks at one or more diffraction angles (2θ) of 15.9±0.2°, 20.5±0.2°, 23.5±0.2°, 28.2±0.2° and 30.7±0.2°,
• wherein the thickener comprises xanthan gum, povidone, colloidal microcrystalline cellulose, or sodium alginate,
• wherein more than 90% of lamotrigine in the suspension is present in the form of the lamotrigine hydrate form A.