Abstract
The effects of various absorption promoters on the pulmonary absorption of drugs with different molecular weights were examined in rats. Phenol red and fluorescein isothiocyanate-labeled dextrans (FDs) with various molecular weights were used as model drugs and the absorption promoters used in this study were sodium glycocholate, sodium salicylate, ethylenediaminetetraacetic acid disodium salt (Na2-EDTA) and sodium caprate, all at a concentration of 1%. Of these absorption promoters, sodium glycocholate and sodium caprate appeared to be more effective for enhancing the pulmonary absorption of these drugs than sodium salicylate and Na2-EDTA. Furthermore, it was indicated that there is the optimal molecular weight to which each absorption promoter gives the largest enhancing effect on the pulmonary absorption of drugs.
