Effect of superdisintegrants and their mode of incorporation on disintegration time and release profile of carbamazepine from immediate release tablet

In this experiment the effect of mode of incorporation of some superdisintegrants such as sodium starch glycolate, croscarmellose sodium, crospovidone (kollidon CL), ludiflash and Xanthan gum (XG) on dissolution profile and disintegration time of carbamazepine (CBZ), apoorly water soluble drug was studied. The superdisintegrants were incorporated by extragranularly, intragranularly and in direct compression method. Different amount of superdisintegrants (1%, 3% and 6%) was incorporated in different formulations whereas all the other excipients as well as the active drug remained same. The results indicated that sodium starch glycolate, when incorporated extragranularly in wet granulation method significantly enhanced the release profile of CBZ. Kollidon CL was the most effective superdisintegrant in decreasing disintegration time of different tablet formulations (1.95 minutes when extragranularly incorporated). On the other hand, tablets prepared with SSG were found most effective in % drug release irrespective of its mode of incorporation (99.99% when extragranularly incorporated and 99.75 when intragranularly incorporated within one hour). Tablets prepared by direct compression method also showed similar drug release with other methods but tablet hardness was found lower. So addition of superdisintegrants in tablet formulation may be an effective technique to comply compendial drug release.