Reference product is the material basis of national drug standards, it is a special measure used to check the quality of drugs; It is the benchmark for measuring drug quality; It is also used as a material standard for calibration of test instruments and methods; In drug testing, it is a control to determine the authenticity of drugs, is an essential tool to control the quality of drugs. The following small series to introduce the reference product calibration method need to pay attention to several matters.

We need to pay attention to several elements when selecting calibration methods for reference products, and we can choose the appropriate calibration method from these elements.

1, the amount of products used to do the experiment should meet: the titration liquid is about 20ml, to meet the accuracy requirements;

2, the judgment requirements of titrant must be clear and strict, and provide titration curve, such as the selection of indicator method, should consider its sensitivity to change color, and calibrate its end color with potential method;

3. In order to exclude the influence of impurities mixed with other reagents on the determination results, or to facilitate the calculation of residual titration, the method of "correcting the titration results with blank test" can be used;

4, to give the titration degree (using four significant digits) derivation process. The calibration results shall be based on the results of no less than 15 groups of determination results from more than 3 laboratories, after statistical analysis, the results of removing outliers and suspicious values, and the reliability limit shall be reported.

If there is a problem with the source of the reference product, it will also directly affect the quality of the product. On-site inspection found that the reference products used by some enterprises are refined apis or "operational reference products", although approved by the relevant departments, but most of the enterprises do not rule its re-standard period and storage conditions, the use period is not verified, and the record is incomplete, it is difficult to trace the source.

Secondly, the management of reference products is not in place. At present, most enterprises do not verify the reference products as required before using them; For the convenience of some enterprises, the reference product is prepared into a higher concentration of storage liquid, but the stability and storage period have not been investigated; Some enterprises do not handle the reference products after opening, and still continue to use them together with the unopened reference products, and there is no mark on the packaging.

Reference products of drugs refer to substances used for physical and chemical tests and biological experiments of drugs, and their concentration is easily reduced if they are not properly handled or beyond the use period. This may make the low content of drugs through inspection to become qualified drugs, but also affect the quality control of raw materials and intermediates. Therefore, drug manufacturers should strengthen the management of reference products.

The above content is the reference product calibration method need to pay attention to the introduction of several matters, to master the origin of the reference product, to use the nationally recognized reference product, and according to the requirements of its relevant verification; It is necessary to verify the storage conditions and use period of the "operation reference product", the unsealed reference product and the storage liquid of the reference product, and make clear rules and do a good job of various records; The account of the reference products should be handled according to the requirements, registered, and stored under the rules; It is suggested that the supplier of the reference product should provide the reference product operation instructions together, and specify the use period and storage conditions.