Development of AgNPs-tragacanth Conjugated Gel as a Novel Green Membrane in Electro-membrane Extraction: Tenofovir Disoproxil Fumarate Assay in Human Plasma Samples

AgNPs-tragacanth conjugate gel as an eco-friendly and low cost membrane was applied for the effective electromembrane extraction (EME) of tenofovir disoproxil fumarate, an important acidic and high polar (logp = 1.25) antiviral drug, followed by HPLC-UV determination. The effect of various parameters on the extraction efficiency including the presence of AgNPs, tragacanth gum concentration, gel thickness, pH values of the donor and acceptor phases, applied voltage, extraction time and agitation rate were investigated and optimized. The best extraction efficiency was obtained at 2.5% w/v of tragacanth gum, 4.0 mm gel thickness, donor phase pH = 7.0, acceptor phase pH = 8.0, applied voltage: 30 V, extraction time: 15 min and agitation rate: 500 rpm. During the method validation, under the optimized conditions, a good linearity dynamic range (LDR), ranging in 10-750 ng ml-1, with coefficient of determination (R2) = 0.999 was obtained. Limit of detection (LOD) and limit of quantitation (LOQ) were estimated to be 5.55 ng ml-1 and 10 ng ml-1, respectively. According to the verified results, the RSD values for intra and inter-day precisions were in the range of 0.53-10.04% and the relative error (RE%) ranged between -2.31 and 8.20%. Finally the applicability of this method in real samples was confirmed by an acceptable performance in extraction and determination of TDF in human plasma samples.