凯式定氮法替代苦味酸法测定注射用A型肉毒毒素中明胶含量的可行性研究

The feasibility study on the detection of gelatin content of botulinum toxin type A for injection by total nitrogen method instead of picric acid method

目的探究采用凯式定氮法替代苦味酸法测定注射用A型肉毒毒素(botulinum toxin type A for injection)明胶含量的可行性,以期对注射用A型肉毒毒素明胶含量测定方法的变更起到借鉴作用。方法通过专属性、准确度、重复性、中间精密度和耐用性验证,确认采用凯式定氮法测定注射用A型肉毒毒素明胶含量的数据可靠性;对凯式定氮法与现有苦味酸法测定注射用A型肉毒毒素明胶含量的结果采用配对t检验和Bland-Altman分析进行统计学分析,确定2种测定方法的一致性。结果注射用A型肉毒毒素中右旋糖酐20、蔗糖、A型肉毒毒素复合物对明胶含量测定无干扰,该方法专属性良好;准确度回收率位于95%~99%之间;重复性RSD为0.73%;中间精密度RSD为2.10%;且耐用性良好,可采用凯式定氮法进行注射用A型肉毒毒素明胶含量的测定。同时与现有苦味酸法相比,配对t检验无统计学差异;Bland-Altman分析,2种方法测量的差值均位于测量差均值的95%置信区间内,说明2种方法一致性良好。结论可采用凯式定氮法替代苦味酸法进行注射用A型肉毒毒素明胶含量的测定。

Objective Evaluating the feasibility on the detection of gelatin content of botulinum toxin type A for injection by total nitrogen method instead of picric acid method,guiding the change of the gelatin detection method.Methods The reliability of the data made by the total nitrogen method was confirmed by verification of specificity,accuracy,repeatability,intermediate precision and ruggedness.Paired t test and Bland-Altman analysis were used for statistical analysis to determine the consistency of the two methods of total nitrogen and picric acid.Results Dextran 20,sucrose and botulinum toxin type A complex did not interfere with the gelatin content detection,the specificity of method was good.The accuracy recovery rate was between 95%and 99%.The repeatability RSD was 0.73%.The intermediate precision RSD was 2.10%.And the durability was good.Thus,the method of total nitrogen can be used for the gelatin content detection of botulinum toxin type A for injection.At the same time,compared with the existing picric acid method,there was not statistical difference in paired t test.The Bland-Altman analysis shows that the difference values measured by the two methods were all within the 95%confidence interval of the mean difference value,indicating that the two methods were in good consistency.Conclusion The total nitrogen method can be used instead of the picric acid method to detect the gelatin content of botulinum toxin type A for injection.