Formulation and evaluation of orally disintegrating tablet of Rizatriptan using natural superdisintegrant

Rizatriptan benzoate is a potent and selective 5-HT1B/1D receptor agonist and is effective for the treatment of acute migraine. Difficulty in swallowing is common among all age groups, especially elderly and pediatrics. Orally disintegrating tablets may constitute an innovative dosage form that overcome the problem of swallowing and provides a quick onset of action. This study was aimed to formulate and evaluate an Orally Disintegrating Tablet (ODT) containing Rizatriptan while using semi-synthetic and natural superdisintegrants. Orodispersible tablets were prepared by direct compression using natural superdisntegrant (Plantago ovata mucilage) and semi-synthetic superdisntegrant (crospovidone). The prepared tablets were evaluated for hardness, friability, thickness, drug content uniformity, water absorption and wetting time. A 32 factorial design was used to investigate the effect of independent variables (amount of crospovidone and Plantago ovata mucilage) on dependent variables [disintegration time, wetting time and Q5 (cumulative amount of drug release after 5 minutes)]. A counter plot was also presented to graphically represent the effect of independent variable on the disintegration time, wetting time and Q5. The check point batch was also prepared to prove the validity of the evolved mathematical model. The systematic formulation approach helped in understanding the effect of formulation processing variable. According to the results of optimized batches, the best concentration of superdisintegrant were as follows: 9.4 mg Psyllium mucilage and 8.32 mg crospovidone gave rapid disintegration in 35sec and showed 99% drug release within 5 minutes. Plantago ovata mucilage, a natural superdisintegrant, gives a rapid disintegration and high release when used with synthetic superdisntegrant in formulation of orally disintegrating tablet of Rizatriptan.