Comparative study on absorption of Luodian Borneolum and muscone after nasal unidirectional perfusion with different Xingnaojing preparations in rats Nasal absorption of iridoids in Xingnaojing Nasal absorption of iridoids in Xingnaojing Effect of salvianolic acid B on nasal absorption in rats in situ Study on rat nasal absorption in situ of borneol based on single pass perfusion method A Study on Nasal Absorption of Psoralen and Isopsoralen in Psoralea corylifolia L. Effect of the Extract of Root of Glycyrrhiza uralensis on the Absorption of Psoralen and Isopsoralen by Nasal Mucosa