A reference substance is a reference substance used for the determination of content or titer in biological assays, antibiotics or biological drugs, expressed in titer units (U).

Reference substance refers to the standard substance used for identification, inspection, content determination and calibration of the performance of the calibration instrument.

National drug standards and reference products are an integral part of national drug standards. The national drug standard substance is the material basis of the national drug standard, the benchmark for measuring drug quality, and the material standard for correcting test instruments and methods. In drug testing, it is the control of the authenticity of drugs, and an essential tool for controlling drug quality.

In the literature, the two concepts are often confused, and the reference product is the standard product, which is only one substance and two formulations. The reason for the error may be that some drugs have both reference products and standard products. Even if the standard and reference products of the same substance, their specifications, calibration methods and uses may be different.

The mixing of reference or standard, that is, the use of reference or standard for content determination other than its calibration method, is a frequent but neglected problem in drug testing. Although there is a good correlation between the content of different calibration methods for the same batch of reference products, the national standard network arrangement is not exactly the same, and sometimes the difference is very large.

Although the Chinese Pharmacopoeia Code clearly stipulates that the reference products issued by the Ministry of Health should only be used for the analytical methods specified in the text. But because:

1. The reference product instruction manual provided by the Ministry of Health is not detailed enough, and most of them have no quality requirements and calibration methods for reference products;

2, lack of understanding of the correct use of reference products or standard products;

3. It is extremely difficult to find corresponding reference products in daily scientific research;

4, the Chinese pharmacopoeia text also often exists the problem of mixing of reference products, such as the standard product or reference product used for content determination is often used for dissolution inspection, and the content determination method and dissolution analysis method are different, so it is easy to cause mixing.

The above content is an introduction to what is the standard product and the reference product, the reference product is a specific substance used for the physical and chemical determination of biological products, prepared by the production unit using the same method as the production process of the product. The reference product should be as consistent as possible with the formula of the product stock, and if the stability is poor, it can be added without appropriate stabilizer that interferes with the determination of substances. The reference product shall be reviewed and approved by the national drug verification agency, and its standard shall not be lower than the quality standard of the product.