Exploring the Impact of Co-60 Gamma Radiation on the Physicochemical Properties of Ethyl Cellulose

Ethyl cellulose (EC) is a non-toxic, tasteless and biocompatible polymer derivative of Cellulose. Due to its biocompatible and hydrophobic nature, EC is extensively used as an encapsulating material for the controlled release of drugs. Gamma radiation sterilization has proven to be the most efficient and acceptable method worldwide for sterilizing the final drug products. Gamma sterilization has more advantages than convention methods like high penetrating power, isothermal character and non-residual. It assures killing the micro-organisms by breaking nucleic acid and halts cell division. In the present study, dried EC was packed in a thin polyethylene sheet and are irradiated with Co-60 gamma source, delivering doses 30, 60, and 90 kGy. Irradiation has produced the radicals of type \( - {{{\text{C}}}_{{\text{2}}}}{{{\text{H}}}_{{\text{5}}}}{{\dot {\text{O}}}}\), which appeared only at higher doses, i.e., 60 and 90 kGy. X-ray diffraction depicts a gradual decrease in crystallinity following radiation dose, though EC is semi-crystalline. Differential scanning calorimetry thermograms indicate a slight decrease in melting temperature following radiation dose. Significant changes were observed in Infrared spectra on irradiating to higher doses. Scanning electron microscope images indicate that EC granules are irregularly shaped with rough patches. The physicochemical properties of irradiated EC were studied and it is observed that there are minimal effects of radiation on EC up to 30 kGy.