Fast Dissolving Tablets of Fexofenadine HCl by Effervescent Method

In the present work, fast dissolving tablets of fexofenadine HCl were prepared by effervescent method with a view to enhance patient compliance. Three super-disintegrants viz., crospovidone, croscarmellose sodium and sodium starch glycolate along with sodium bicarbonate and anhydrous citric acid in different ratios were used and directly compressible mannitol (Pearlitol SD 200) to enhance mouth feel. The prepared batches of tablets were evaluated for hardness, friability, drug content uniformity and in vitro dispersion time. Based on the in vitro dispersion time (approximately 20 s), three formulations were tested for in vitro drug release pattern in pH 6.8 phosphate buffer, short-term stability at 40 degrees /75% RH for 3 mo and drug-excipient interaction (IR spectroscopy). Among the three promising formulations, the formulation ECP(3) containing 8% w/w of crospovidone and mixture of 24% w/w sodium bicarbonate 18% w/w of anhydrous citric acid emerged as the best (t(50%) 4 min) based on the in vitro drug release characteristics compared to conventional commercial tablet formulation (t(50%) 15 min). Short-term stability studies on the formulations indicated that there are no significant changes in drug content and in vitro dispersion time (P<0.05).