Two-week oral mucosal irritation study with ramosetron orally disintegrating tablets in Syrian hamsters

The potential of ramosetron ((R)-5-[(1-methyl-3-indolyl)carbonyl]-4,5,6,7-tetrahydro-1 H-benzimidazole hydrochloride, CAS 132907-72-3, YM060) orally disintegrating tablets to cause irritation to the oral mucosa was assessed in a group of six male and six female Syrian hamsters. Each animal was given one tablet containing 0.1 mg YM060 into the right cheek pouch once daily for 14 consecutive days. A neck collar was fitted for 1 h after each administration to ensure that the tablet was not expelled. A similarly constituted group of hamsters received placebo tablets and acted as a contemporaneous control. Left and right cheek pouches were examined before dosing each day, and on the day following the last treatment. At the end of the treatment period the animals were killed, the cheek pouches excised and examined macroscopically. The cheek pouches of all animals were assessed for histopathological change. There were no signs to indicate systemic or local reactions to treatment in any animal. Macroscopic and microscopic examination of the cheek pouches did not reveal any treatment-related effect. It is concluded that YM060 orally disintegrating tablets are non-irritant to the hamster oral mucosa.