Nasal absorption in the rat i. a method to demonstrate the histological effects of nasal formulations
Chandler, S.G.; Illum, L.; Thomas, N.W.
International Journal of Pharmaceutics (Kidlington) 70(1-2): 19-28
A method is described which enables the controlled assessment of the effects of intranasal drug formulations on rat nasal epithelium. Damage to the nasal mucosa caused by the surfactant laureth-9 (1% w/v) was used as an indicator of the distribution of dose volumes (100, 50 and 20 .mu.l) administered to one side of the nasal cavity. Only the 20 .mu.l volume was retained exclusively in the dosed side. Using this dose volume therefore, the epithelium on the undosed side could be used as control tissue and a direct comparison made between experimental and control tissue in the same section. Errors due to inter-animal variability and tissue sampling are thus minimised, and the total number of animals required for future studies reduced.