Abstract

Migraine, a neurological condition is often associated with intense, throbbing, crippling headaches for hours to days. Rizatriptan benzoate has established its potential in controlling the symptoms of migraine. The present study aims to formulate a bilayer tablet of rizatriptan with multi release unit matrix embedded in the sustained layer to achieve a pulsatile release of the drug to control the various phases of migraine. A preliminary study on four matrices-F1, F2, F3 and F4 with different proportion of carnauba wax and ethyl cellulose was done to evaluate the release pattern of rizatriptan in fasted state simulated intestinal fluid at pH 6.5. A simplex lattice design was used to find out the optimized ratio of the matrices to control the dissolution of rizatriptan benzoate in a predetermined fashion at different hour’s intervals. The release profile was optimized with a blend of three different formulations (F1:F2:F3=0.53:0.24:0.23). Statistical analysis revealed that the percentage error between the predicted and optimum blend was less than 5 %. The immediate release layer was formulated with direct compression method using super disintegrants. The evaluation of bilayer tablet was done for hardness, weight variation, friability, uniformity of content and percentage release. The tablet met the criteria of pharmacopoeial requirements. The bilayer tablet of rizatriptan benzoate could able to release the drug instantly as comparable with marketed immediate release tablet of rizatriptan benzoate and could also prolong the release for 24 h. The accelerated stability study also showed the tablets could retain their property at variable temperature and humidity. Therefore, it can be concluded that the bilayer tablet of rizatriptan benzoate embedded in a wax polymer multi release unit matrix has a potential to deliver the drug at a predetermined rate for the effective control of migraine.