1978 年 98 巻 6 号 p. 715-719
The binding properties of prazepam, desalkylprazepam, and diazepam to human serum albumin (HSA) were studied. Protein-bound drug and unbound drug were separated by Sephadex gel filtration. Binding ability of the test drugs to HSA decreased in the order of diazepam, desalkylprazepam, and prazepam. HSA was found to have just one class of binding site for prazepam, but had two different binding sites for diazepam and desalkylprazepam. Binding of the primary site for diazepam and desalkylprazepam was high, whereas that of the secondary site was low. The reason why the intact prazepam level in plasma was very low after its oral administration was discussed from the viewpoint of the binding properties of prazepam to HSA.