• Archives of Pharmacal Research
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• v.9 no.1
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• pp.49-54
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• 1986

Effect of sodium taurodeoxycholate (TDC) infused intravenously on the pharmacokinetics of methylene blue (MB) was studied in the rat to investigate the role of ion-pair complexation in the body on drug elimination and disposition. Distribution volume (Vd) of MB was increased significantly (p< 0.05) by TDC infusion. Considering together with the fact that apparent partition coefficient (APC) of MB between phosphate buffer (pH 7.4) and n-octanol was increased markedly by TDC, the increase in Vd seemed to be the result of decreased polarity of MB by ion-pair formation with TDC. But total body clearance (CLt) and biliary excretion clearance (CLbil) of MB were not increased significantly by TDC.

• Archives of Pharmacal Research
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• v.9 no.2
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• pp.111-114
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• 1986

Bretylium tosylate is a quaternary ammonium compound used for the treatment of ventricular fibrilation in humans. It is advantageous to other cationic compound in the study of biliary excretion in that negligible amount is bound to plasma protein and metabolite is not likely is to be formed. Some researchers reported that the formation of ion-pair complex caused to increase the lipothilicity of cationic compound. The partition of bretylium between water and organic phase was increased with the addition of sodium taurodeoxycholate. Also sensitive gas chromatographical assay procedure using flame ionization detector was studied. This procedure can detect as low as 0.1 mg/ml using 0.1 ml biological sample, but contamination by previous injection is the major problem of this method.