¹Department of Pharmaceutical Technology, Faculty of Pharmacy, Hacettepe University, Ankara, Turkey DOI : 10.29228/jrp.211 This study aimed to examine the effects of various surfactants on the particle size distribution of albumin (HSA) nanoparticles and the binding efficiency of the active substance to albumin. Therefore, gefitinib, an EGFR tyrosine kinase inhibitor and albumin nanoparticles were manufactured using Nab™ technology with various surfactants at different levels. Before producing gefitinib-albumin nanoparticles, the fluorescence spectroscopy method in the absence and presence of surfactants was used to demonstrate the binding of the gefitinib to albumin. Gefitinib binding to HSA in the presence and absence of surfactants, was demonstrated with Stern-Volmer plots. In order to optimize the nanoparticle production method, the effects of critical process parameters such as organic phase volume: total volume %, drug:HSA ratio, homogenization cycle number on particle size distribution were evaluated using the Box-Behnken design. After optimization of production method, the nanoparticles were produced by adding three different levels of DPPC, HSPC, and oleic acid to the formulation, and the effects of surfactants on the particle size distribution and zeta potential were evaluated. Adding surfactants had no statistically significant effect on the Stern Volmer plots but they helped to produce uniform nanoparticles with PDI and particle size values of less than 0.2 and 130 nm respectively. It was observed that adding HSPC, DPPC, or oleic acid to the formulation enabled the production of uniform albumin nanoparticles. Keywords : Surfactant, HSPC, DPPC, oleic acid, gefitinib, human serum albumin, Nab™ technology