Improvement of dissolution properties of lamotrigine by inclusion complexation and solid dispersion technique

The aim of the present work was to improve the dissolution characteristics of the poorly water soluble antiepileptic drug lamotrigine (LMN) by inclusion complexation using hydroxy propyl beta-cyclodextrin (HP beta-CD) by co-evaporation technique and by, solid dispersion, prepared by the melt method using poloxamer 407 (L 127). Phase solubility studies showed A(L) type curves with both the carriers. Dissolution of LMN was significantly improved (p < 0.05) by inclusion complexation and solid dispersion preparation. Results of solid state characterization performed by Fourier Transform Infrared Spectroscopy, Differential Scanning Calorimetry and Powder X-ray Diffractrometry techniques revealed a decrease in the crystallinity of LMN that might be accounting for improvement in the dissolution properties as seen from dissolution studies.