Buccal absorption of ergotamine tartrate using the bioadhesive tablet system in guinea-pigs

The buccal administration of ergotamine tartrate (ET) combined with polyvinyl alcohol (PVA) gel brought about higher plasma concentration of ET compared with that of oral administration of capsules in guinea-pigs. T(max) of ET in plasma of buccal administration was significantly smaller than that of oral administration. For the buccal dosage form of ET, the bioadhesive tablet system (BTS) was newly developed. It consisted of a reservoir of drug and an adhesive region. BTS showed better absorption of ET compared with PVA gel in guinea pigs. Among several pharmaceutical bases in the reservoir of BTS, Witepsol W-35 was most effective. It is likely that the high lipophilic property of Witepsol W-35 in which ET was dissolved facilitated the drug release by its relatively low melting point (around 35 degrees C), consequently a rapid absorption. In addition, the enhancing activity of the cod-liver oil extract (CLOE) in hydrophilic ointment on the in vivo buccal ET absorption was clarified to be comparable to that in the in vitro study utilizing the keratinized epithelial-free membrane (KEF-membrane) of the hamster cheek pouch.