In vivo bioavailability studies of sumatriptan succinate buccal tablets

Back ground and the purpose of study: Sumatriptan succinate is a Serotonin 5- HT1 receptor agonist, used in treatment of migraine. It is absorbed rapidly but incompletely when given orally and undergoes first - pass metabolism, resulting in a low absolute bioavailability of about 15%. The aim of this work was to design mucoadhesive bilayered buccal tablets of sumatriptan succinate to improve its bioavailability. Methods:Mucoadhesive polymers carbopol 934 (Carbopol), HPMC K4M, HPMC K15M along with ethyl cellulose as an impermeable backing layer were used for the preparation of mucoadhesive bilayered tablets . In vivo bioavailability studies was also conducted in rabbits for optimized formulation using oral solution of sumatriptan succinate as standard. Results:Bilayered buccal tablets (BBT) containing the mixture of Carbopol and HPMC K4M in the ratio 1:1 (T1) had the maximum percentage of in vitro drug release within 6 hrs. The optimized formulation (T1) followed non-Fickian release mechanism. The percentage relative bioavailability of sumatriptan succinate from selected bilayered buccal tablets (T1) was found to be 140.78%. Conclusions: Bilayered buccal tablets of sumatriptan succinate was successfully prepared with improved bioavailability.