Hollow Fiber-in-Syringe Equilibrium Sampling Through Supported-Liquid Membrane for Evaluation of Drug-Plasma Binding.

The aim was to evaluate drug-plasma binding (DPB).by employing Hollow Fiber-in-Syringe Equilibrium Sampling Through Supported Liquid Membrane (HFiS ESTSLM) and RP-HPLC analysis. HFiS ESTSLM and RP-HPLC were used to evaluate DPB of three weak basic drugs (Metoprolol, Diphenhydramine, and Sildenafil) with differing hydrophilicity and binding ability to blood plasma. The results exhibited an increasing drug-dependent magnitude of DPB for the three model drugs. This trend of DPB confirmed that HFiS ESTSLM has the required sensitivity for determining DPB of the drugs. The DPB was drug concentration-dependent within the tested drug concentration range, especially at high concentration. HFiS ESTSLM and RP-HPLC offered a simple, easy and cost-effective procedure to evaluate DPB of these basic drugs.