Innovative synthetic biodegradable polymers containing amino acid moieties for inhalation anticancer drug delivery systems are to efficiently administer drugs in a controlled manner while also altering the physical and chemical characteristics and the way therapeutic molecules are processed to the lung. In this study, the focus was to prepare a new polyamide based on L-cystine amino acid loaded with a combination of thymoquinone (TQ) and doxorubicin (DOX) nanocapsules (TQ-DOX/Cys-Py/PA) NCs to be delivered directly to the lung. (TQ-DOX/Cys-Py/PA) NCs were created using a single-step interfacial polycondensation method and were assessed for their content uniformity, particle size distribution, Fourier-transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), differential scanning calorimetry (DSC), Thermogravimetric analysis (TGA), X-ray diffraction (XRD), and aerodynamic performance (both in vitro and in vivo). The aerodynamic performance assessment represents that the prepared (TQ-DOX/Cys-Py/PA) NCs were able to emit 98.7 % and 97.1 % of TQ and DOX nominated dose, respectively. And 2008.2 and 110.2 mcg of TQ and DOX emitted doses can reach the lower parts of the respiratory system and has an aerodynamic particle size between 1-5 µm. Which revealed that the optimum formulation would produce small particle size (19.89 nm) with high entrapment efficiency (TQ:85.4 %, DOX:99.49 %) and loading efficiency of (TQ:52.2 %, DOX: 15.03). The targeted release of TQ and DOX in 0.1 M Glutathione-containing buffer solution demonstrated a faster onset of action with 50 % released within the first 2h. In vivo studies were conducted to demonstrate the efficacy of (TQ-DOX/Cys-Py/PA) NCs in enabling targeted delivery to the lung for the treatment of lung cancer. The results demonstrated exceptional lung targeting and sustained lung retention for at least 24 h. Furthermore, the toxicity of the (TQ-DOX/Cys-Py/PA) NCs was assessed by quantifying the protein carbonyl content. The results showed that the (TQ-DOX/Cys-Py/PA) NCs exhibited reduced toxicity in the heart, liver, and kidney compared to free DOX and (DOX/Cys-Py/PA) NCs. In conclusion, (TQ-DOX/Cys-Py/PA) NCs are a promising drug lung delivery system for treating cancer via inhalation rout.