The approval number of a drug is the registration number of the company approved by the state to produce the variety, and is unique to the company producing the variety with the same specifications. The validity period is the validity period of the variety and specification, and should be consistent. It should be true. The approval number of the drug is unchanged, and the validity period should be consistent, such as 2 years, or the validity period of 201104 means that it is valid until April 30, 2011. It should be approved for production in May 2009, and the batch number The difference is that multiple batches were produced in May 2009. Of course it is different. If there is a problem with product quality, it is easier to track and trace the cause.