Accuracy assessment on the analysis of unbound drug in plasma by comparing traditional centrifugal ultrafiltration with hollow fiber centrifugal ultrafiltration and application in pharmacokinetic study

Pretreatment of plasma samples by a novel hollow fiber centrifugal ultrafiltration technique for the determination of plasma protein binding of three coumarins using acetone as protein binding releasing agent

“…In our previous work, HFCF-UF has been introduced to determine the unbound drug concentration and excellent results have been achieved [21][22][23]42]. This method introduces hollow fiber membrane as the media to intercept biological macromolecular matrix, so that the small molecule drugs can pass through the hollow fiber membrane freely.…”

“…Since the direction of centrifugal force is completely parallel to the hollow fiber membrane, concentration polarization is avoided and the small molecules can pass through the membrane freely [24,25]. Furthermore, ignorable amount of ultrafiltrate is withdrawn from the hollow fiber compared with plasma sample in the slim glass tube, therefore, drug-protein binding equilibrium in plasma sample is stable, which would likely contribute to a more accurate result [21][22][23].…”

“…Hollow fiber centrifugal ultrafiltration (HFCF-UF), a simple device composed of a slim glass tube and a U-shaped hollow fiber, has been introduced for the separation of unbound drug fraction from plasma sample [21][22][23]. Since the direction of centrifugal force is completely parallel to the hollow fiber membrane, concentration polarization is avoided and the small molecules can pass through the membrane freely [24,25].…”

A study on characteristic of different sample pretreatment methods to evaluate the entrapment efficiency of liposomes

“…HF-CF-UF is mainly applied the pore size of hollow fiber to isolate accurately minor and micro molecules from complicated matrix under equilibrium state [27][28][29]. The centrifugal force is completely parallel to the hollow fiber membrane [16], which could eliminate the concentration polarization.…”

The significance of a new parameter – plasma protein binding – in therapeutic drug monitoring and its application to carbamazepine in epileptic patients

“…So, controlling the ratio of the ultraltrate to the sample solution in CF-UF is a challenge for operators, especially for different plasma conditions, such as blood viscosity, protein levels, osmotic pressure and so on. [11][12][13] Meanwhile, more errors can be also introduced from using C t monitoring procedures with another disparate device, such as LLE, PPT. 14,15 These methods are unsuitable for C t monitoring due to unsatisfactory recovery and poor reproducibility obtained from multi-step manipulation procedures, phase change processes and plasma conditions, thus the accuracy of the results needs to be examined as they could mislead the physician in clinical treatment.…”