*P. Bhatt, M. Patel
Department of Pharma. Technology,
L.J. Institute of Pharmacy, Ahmedabad, Gujarat, India
Rizatriptan benzoateis an anti migraine drug. The therapeutic activity of the drug can most likely be attributed to agonist effects at 5-HT1B/1D receptors. It is well absorbed from the gastrointestinal tract, but its oral bioavailability is low (45%) due to first-pass metabolism which makes it an ideal candidate for rapid release drug delivery system. Hence, an attempt was made to prepare and evaluate fast dissolving oral films containing Rizatriptan benzoate as a model drug by solvent casting method using hydrophilic polymers. Various formulations were developed with varying concentration of polymers like HPMC, PVA, PVP K30, Xanthan gum, Guar gum. Citric acid was used as a saliva stimulating agent and Propylene glycol as a plasticizer. The prepared oral films were evaluated for their physicochemical and mechanical parameters such as Physical appearance, surface pH, thickness uniformity, disintegration time, drug content uniformity, folding endurance, tensile strength, percentage elongation, in-vitro drug release. In-vitro release rate of Rizatriptan benzoate was studied in simulated saliva fluid (pH 6.8). From prepared formulations, the optimized plasticizer and polymer combination was selected and 32 factorial design was applied. On basis of factorial design, RSM and contour plots were applied. From factorial design batches the batch with lower disintegration time and good mechanical properties is optimized. This optimized batch was studied for its stability for 1 month. PG was optimized as plasticizer. It was observed that no single polymer was able to produce the film with desired quality hence polymer combination was used. The polymer combination of HPMC E 15 & PVA was optimized. On applying factorial design to this combination, batch with polymer ratio of 1:7 (HPMC: PVA) was optimized. The formulation was found stable after 1 month.