Detection of biological activity of insulin degludec by homogeneous time-resolved fluorescence
In this study,the CHO_INSR_1284 transgenic cell line was employed as the target cell,utilizing homogeneous time-resolved fluorescence technology to establish a method for detecting the biological activity of insulin degludec.Key parameters were optimized,and validation was conducted in accordance with general principles 9401 and 1431 of the fourth section of the 2020 edition of the Chinese Pharmacopoeia.Results indicated a good dose-response relationship for insulin degludec in this method,aligning with a four-parameter curve.Following optimization,the cell seeding density was set at 3.5× 105 cell·mL-1,the initial concentration of insulin degludec at 57.18 μg·mL-1,with a four-fold dilution,a stimulation period of 45 minutes,and an incubation duration of 4 hours.This method demonstrated strong specificity,with the geometric variation coefficient(GCV%)for the five potency levels ranging from 4.1%to 10.6%.The linear regression equation from the linear fitting was y=1.015x-0.027 7,and R2=0.999 6.The results confirmed the method's good intermediate precision and linearity.The regression term was highly significant(P<0.01),neither the deviation from parallel terms nor the model mismatch terms were significant(P ≥ 0.05),complying with general rule 1431 of the fourth section of the 2020 edition of the Chinese Pharmacopoeia.This study established a method for detecting the biological activity of insulin degludec using homogeneous time-resolved fluorescence technology,suitable for evaluating the biological activity and quality control of insulin degludec products.