Tensor 270

The obtained copolymer was characterized through Fourier transform infrared spectroscopy (FT-IR, Tensor 270/Bruker, Germany). Proton nuclear magnetic resonance (¹H-NMR) spectroscopy (in CDCl₃) was recorded on an ultra-shield 400 spectrometer (Bruker, Germany) at 400 MHz. The molecular weight and polydispersity of PCEC copolymer were determined using GPC (Shimadzu LC-20A). The sample was dissolved in tetrahydrofuran (THF) at a concentration of 1-2 mg/2 mL for this purpose. At a rate of 1.0 mL/min, THF was eluted. The external and column temperature were kept at 35°C.The size and morphology of the drug-loaded PCEC NPs were determined by field emission scanning electron microscopy (FE-SEM) (MIRA3 FEG-SEM/TESCAN). Dried NPs were mounted on a tape, coated with a thin layer of gold, and images were obtained at a voltage of 15 kV. Moreover, the particle size and zeta potential of thedrug-loaded PCEC NPs were determined by dynamic light scattering (DLS) analysis using a zetasizer nano ZS90 (Malvern Instruments, UK).

Fatty acid composition of Croton macrostachyus seed oil extracted by using n-hexane was determined according to the AOCS 1998 official methods via Gas Chromatography mass spectrometer (Palo Alto, CA, USA, 7820A) equipped with flame ionization detector analysis. The oil composition was investigated after carboxyl acid alkyl radical esters mixed with a methanolic solution of potassium hydroxide using gas chromatography. The analysis was performed using nitrogen gas for heating the sample for the subsequent temperature profiles. First temperature of the sample was heated at 60 °C for one minute, then increased from 60 °C to 170 °C at a rate of 10 °C/min, 170–230 °C at a rate of three °C/min, and constantly heated for 15 min at 230 °C. Finally, the sample was injected at volumetric rate of 1 ml/min by a sampler injector at the temperatures of 225 °C and detected at 250 °C. Then fatty acids composition of Croton macrostachyus seed oil was identified based on peak retaining time.
Fourier transform infrared (FTIR) spectrometer (Bruker Tensor 270, Ettlingen, Germany) was used to determine various functional groups in the extracted oil and the spectra were recorded from 4000 to 400 cm⁻¹. The analysis was done using KBr for extracted Croton macrostachyus seed oil.