In this study, we constructed a GLP-2R-HEK293 cell line and established a method for the determination of the in vitro biological activity of teduglutide based on HTRF, after optimizing experimental conditions and methodological verification. We also carried out relative potency detection of teduglutide pharmaceutical products using this method. The result showed that there was a quantitative-efficient relationship between the teduglutide activity and cAMP contents in GLP-2R-HEK293 cells, which conformed to four-parameter model. Method verification results of five concentrations of teduglutide (64%, 80%, 100%, 125% and 156%) met the requirements of the General Rules of Chinese Pharmacopoeia, 2020 edition, Volume IV (9401). We then analyzed the relative potency of three batches of teduglutide drug substances and three batches of drug products. The linearity, regression and parallelism of the obtained curves all fit the system suitability requirements. The relative potency of six batches of teduglutide was from 83% to 105%. In summary, the biological activity detection method established in this study was accurate, precise, simple and time-saving, which can be used for quality control of teduglutide pharmaceutical products.

This study constructed a LHCGR-CRE-luc-HEK293 transgenic cell line according to the activation of the cAMP signaling pathway after recombinant human chorionic gonadotropin binding to the receptor. The biological activity of recombinant human chorionic gonadotropin was assayed using a luciferase assay system. The relative potency of the samples was calculated using four-parameter model. And the method conditions were optimized to validate the specificity, relative accuracy, precision and linearity of the method. The results showed that there was a quantitative potency relationship of human chorinonic gonadotropin (hCG) in the method and it was in accordance with the four-parameter curve. After optimization, the conditions were determined as hCG dilution concentration of 2.5 μg·mL^-1, dilution ratio of 1∶4, cell number of 10 000-15 000 cells/well, and induction time of 6 h. The method had good specificity, relative accuracy with relative bias ranging from -8.9% to 3.4%, linear regression equation correlation coefficient of 0.996, intermediate precision geometric coefficient of variation ranging from 3.3% to 15.0%, and linearity range of 50% to 200%. This study successfully established and validated a reporter gene method to detect hCG biological activity, which can be used for hCG biological activity assay and quality control.

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.

The Dionex CaboPac^TM PA10 BioLC^TM Analyical 2 mm × 250 mm column was used with a protective column (Dionex CaboPac^TM PA10 BioLC^TM Guard 2 mm × 50 mm). 100 mmol·L^-1 sodium hydroxide solution was used as eluent; the flow rate was 0.25 mL·min^-1. Sample tray temperature: 35 ℃. The pulse amperometric detector was adopted, and the waveform was Gold CWE, Ag-AgCl RE, Carbo, Quad. The samples were cultured with 8 concentrations of glycogen substrates (0.31, 1.25, 2.5, 5, 10, 20, 30, and 40 mg·mL^-1). D-Glucose concentrations were measured at 5 different time points (T0, T1, T2, T3 and T4). The glucose concentration from T1 to T4 minus the glucose concentration at T0. The reaction rate was calculated at different glycogen substrate concentrations. These reaction rates are plotted against substrate concentrations using Michaelis-Menten equation. The kinetic parameters were expressed as V_max (nmol·mg^-1·min^-1) and K_m (mg·mL^-1). The RSD of glucose standard curve R² (n = 6, linear range: 1.25-500 μmol·L^-1) was 0.1% and the RSD (n = 6) of the slope of the standard curve was 2.2%. The mean limit of quantitation was 0.14 μmol·L^-1, and the mean limit of detection was 0.05 μmol·L^-1. The RSD of K_m and V_max were 4.4% and 4.6% respectively in three separate experiments. The durability of the method was good. The method was developed for the on-line automatic determination of the hydrolysis kinetics of acid α-glucosidase (GAA) for injection by ion chromatography. The method has good precision, repeatability and durability, and can be used for the determination of glycogen hydrolysis kinetics of GAA for injection, and could reference value for the enzyme kinetics evaluation of recombinant enzyme replacement therapy.

According to the requirements of the regulatory authorities, degree of modification (DP) should be included in the characterisation of the PEGylated protein drug substance, and is one of the critical quality attributes for quality control. In this study, based on the fundamental assumption that the refractive index (RI) signal and the ultraviolet (UV) signal of PEGylated protein are equal to the sum of the corresponding signal produced by the polyethylene glycol (PEG) and protein parts of the conjugates in their uncoupled state, we developed a method to determine the DP of PEGylated recombinant human growth hormone (inpegsomatropin). In this method, 20 μL of 1 mg·mL^-1 human growth hormone (hGH) standard, 2 mg·mL^-1 PEG reference substance and 1 mg·mL^-1 drug substance solution were each injected to size exclusion chromatographic (SEC) column for separation, detected with ultraviolet and refractive index (UV-RI) detectors in series. Finally, the DP was calculated as the formula derived from the fundamental assumption. The developed SEC-UV-RI method showed good specificity, repeatability (RSD = 0.63%, n = 9) and accuracy, with a recovery of 100.0%, compared with the result obtained from the simultaneously established classical acid hydrolysis method, demonstrating pretty handleability and accessibility, and is appropriate for quality control test of DP for this drug substance.

The goal of this work was to explore the prospect of standardized application of an in-vitro bioactivity assay for recombinant human follicle-stimulating hormone based on a reporter gene. The relative accuracy, intermediate precision, linearity and applicable range of the method were validated according to the General Rules of Chinese Pharmacopoeia 2020 edition Volume IV (9401). Three laboratories used this method to determine the in-vitro biological activities of six batches of drug product and three batches of drug substance manufactured by two different companies. The consistency of the potency determined by three laboratories, the intra-laboratory precision and inter-laboratory precision were analyzed. The method was optimized during the collaborative validation. The results of method validation meet the requirements of the General Rules of Chinese Pharmacopoeia 2020 edition Volume IV (9401). Aiming to resolve the problems found in the collaborative validation, the medium for cell seeding, the pre-diluted buffer solution of standard and sample, and the means of removing and discarding supernatant after stimulation were optimized. After optimization, there was no significant difference in the bioactivity among the different laboratories (P > 0.05), indicating statistical equivalency. Intra-laboratory and inter-laboratory precision were good and the geometric coefficient of variation (GCV%) were both less than 15%. In conclusion, the reporter gene assay has good intra-laboratory repeatability and inter-laboratory reproducibility and is suitable for analyzing recombinant human follicle-stimulating hormone drug product and drug substance by different manufacturers. It is expected to be used as a standardized method for the determination of the in-vitro bioactivity of such products.

In this study, we established a novel bioassay to determine the activity of polyethylene glycolated recombinant human growth hormone (PEG-rhGH) using Nb2-11 cells. We performed experimental condition optimization and methodological verification, and then detected the relative potency of PEG-rhGH products using this method. We demonstrated that the bioactivity of PEG-rhGH in promoting Nb2-11 cell proliferation displays a dose-response relationship, which conformed to the four-parameter model. Using PEG-rhGH reference as a control, we analyzed the relative potency of six batches of PEG-rhGH products, as well as linearity, regression and parallelism of the obtained curves. The relative potency of six batches of PEG-rhGH products was 95% to 105%. These results implied that the new bioassay established may be employed in quality control of PEG-rhGH products.

Objective: To investigate the incidence and risk factors of systemic allergic reactions induced by subcutaneous immunotherapy (SCIT) in patients undergoing SCIT injections in Peking Union Medical College Hospital (PUMCH). Methods: This is a single center retrospective cohort study. Using the outpatient information system of PUMCH, the demographic information and injection-related reaction data of patients undergoing SCIT injection in Allergy Department of PUMCH from December 2018 to December 2022 were retrospectively analyzed to count the incidence and risk factors of systemic allergic reactions caused by SCIT. Mann-Whitney nonparametric test or chi-square test was used for single-factor analysis, and multiple logistic regression was used for multiple-factor analysis. Results: A total of 2 897 patients received 18 070 SCIT injections in Allergy Department during the four years, and 40 systemic allergic reactions occurred, with the overall incidence rate of 0.22%. The incidence of systemic allergic reaction was 0.37% when using imported dust mite preparation and 0.15% when using domestic multi-component allergen preparation. The risk factors significantly related with SCIT-induced systemic allergic reactions in patients using imported dust mite preparation were age less than 18 years old (OR=3.186,95%CI: 1.255-8.085), highest injection concentration (OR value could not be calculated because all patients with systemic reactions were injected with highest concentration), and large local reaction in previous injection (OR=22.264,95%CI: 8.205-60.411). The risk factors for SCIT-induced systemic allergic reactions in patients using domestic allergen preparation were 5 or more types of allergens (OR=3.455,95%CI: 1.147-10.402), highest injection concentration (OR=3.794,95%CI: 1.226-11.740) and large local reaction in previous injection (OR=63.577,95%CI: 22.248-181.683). However, SCIT injection in pollen allergic patients during the pollen season did not show a correlation with systemic allergic reaction. Conclusion: The incidence of SCIT-induced systemic allergic reactions was low in the Chinese patient population of this study. Patients with one or more risk factors, such as multiple allergen injection, highest injection concentration, large local reaction in previous injection, should be given high attention and vigilance against systemic allergic reactions.
Humans ; Allergens ; Asian People ; Desensitization, Immunologic/adverse effects* ; Hypersensitivity/epidemiology* ; Retrospective Studies

Objective: To investigate the incidence and risk factors of systemic allergic reactions induced by subcutaneous immunotherapy (SCIT) in patients undergoing SCIT injections in Peking Union Medical College Hospital (PUMCH). Methods: This is a single center retrospective cohort study. Using the outpatient information system of PUMCH, the demographic information and injection-related reaction data of patients undergoing SCIT injection in Allergy Department of PUMCH from December 2018 to December 2022 were retrospectively analyzed to count the incidence and risk factors of systemic allergic reactions caused by SCIT. Mann-Whitney nonparametric test or chi-square test was used for single-factor analysis, and multiple logistic regression was used for multiple-factor analysis. Results: A total of 2 897 patients received 18 070 SCIT injections in Allergy Department during the four years, and 40 systemic allergic reactions occurred, with the overall incidence rate of 0.22%. The incidence of systemic allergic reaction was 0.37% when using imported dust mite preparation and 0.15% when using domestic multi-component allergen preparation. The risk factors significantly related with SCIT-induced systemic allergic reactions in patients using imported dust mite preparation were age less than 18 years old (OR=3.186,95%CI: 1.255-8.085), highest injection concentration (OR value could not be calculated because all patients with systemic reactions were injected with highest concentration), and large local reaction in previous injection (OR=22.264,95%CI: 8.205-60.411). The risk factors for SCIT-induced systemic allergic reactions in patients using domestic allergen preparation were 5 or more types of allergens (OR=3.455,95%CI: 1.147-10.402), highest injection concentration (OR=3.794,95%CI: 1.226-11.740) and large local reaction in previous injection (OR=63.577,95%CI: 22.248-181.683). However, SCIT injection in pollen allergic patients during the pollen season did not show a correlation with systemic allergic reaction. Conclusion: The incidence of SCIT-induced systemic allergic reactions was low in the Chinese patient population of this study. Patients with one or more risk factors, such as multiple allergen injection, highest injection concentration, large local reaction in previous injection, should be given high attention and vigilance against systemic allergic reactions.
Humans ; Allergens ; Asian People ; Desensitization, Immunologic/adverse effects* ; Hypersensitivity/epidemiology* ; Retrospective Studies

We developed an in-vitro bioassay for determining the bioactivity of human insulin by homogeneous time-resolved fluorescence immunoassay. CHO-INSR B1284 transgenic cells were used as target cells. Key assay parameters, including the cell density, the range of working concentrations, and the stimulation time were optimized. The specificity, relative accuracy, intermediate precision, linearity, and range of the method were validated, as well as the passage stability of the CHO-INSR B1284 cell line. The national standard of recombinant human insulin was used as the benchmark to evaluate the relative potency of insulin analogues and drugs. The drugs and the reference human insulin showed a dose-response relationship, R² > 0.995, which conforms to the four-parameter equation: y = (A - D) / [1 + (x/C)^B] + D. Specificity of the method was good. The geometric mean, relative bias, and geometric coefficient of variation (GCV, %) of the five concentrations (n = 8, 64%, 80%, 100%, 125% and 156%) met the requirements of the General Rules of Chinese Pharmacopoeia, 2020 edition, Volume IV (9401). In summary, a bioassay for determining the in vitro bioactivity of human insulin based on a homogeneous time-resolved fluorescence technique was established; the method was simple, time-saving, accurate and precise, and could be used for the evaluation of biological activity and quality.