When we buy food in the supermarket, we are most concerned about whether it has deteriorated, but in fact, the same needs to be done for medicines. Sometimes we only look at drugs to see if they have expired at best, but in fact for drugs that have not expired there is also the possibility of expiration, because drugs are affected by many factors, the date on the bag is only the preservation date under the specified normal conditions. So we need to know whether the drug is expired when we buy it, or the family has bought the drug is not used up, and wait for the next time you need to use it, to determine whether you can continue to use. Drugs are susceptible to light, temperature, humidity, microbial influence and damage. If the drugs are not stored properly, or stored for too long, it will make the quality of the drugs decline or deteriorate and become ineffective, and using such drugs will cause adverse consequences. Generally speaking, whether the drug is deteriorated depends on the physical and chemical methods, or biological testing methods to test the determination. However, in addition to professional institutions, it is generally difficult to do. A large number of more important methods are to observe the deterioration from the appearance of the drug, and to judge the change of the drug by the five senses. When the following conditions appear, it can no longer be used. 1, injections: observe whether the liquid is clear, whether there is discoloration, etc. Injections, except for a few special varieties allowed to have a slight turbidity, are generally a clear liquid. Where there is obvious turbidity, precipitation or crystallization precipitation, can not be dissolved can not be used. Some herbal injections are also prone to turbidity or precipitation in storage, and should not be used. 2, tablets, capsules: If you find that the tablets have moisture adhesion, loose tablets, deformation, lobes and sugar-coated tablets discoloration or serious spots, mildew, etc. can not be used. If you find that yeast tablets are moldy and insects, vitamin C tablets oxidation and discoloration, aspirin tablets have the sour smell of acetic acid when exposed to moisture, should not be used. Some proprietary Chinese medicines, such as Shujian and blood tablets become brown after moisture absorption, the tablets are loose and sticky should not be used. Capsules are easy to absorb moisture and sticky, if the contents deteriorate, it is not available for medicine. 3.Dispersant: lumps of mold, discoloration and adhesion should not be used. 4, eye drops: after opening to be used up within the prescribed time. If you find that the stored eye drops have discoloration such as flocculent, can not be used. 5, tinctures, ointments, syrups: if the inspection found precipitation, mold, discoloration, etc. can not be used. If belladonna compound is stored for too long and precipitates, do not continue to use it. 6, ointment agent: generally more stable, but the matrix should be checked for rancidity and odor, and should also be checked for oil layer precipitation or crystallization precipitation. If there is an oil layer or crystalline precipitation, after processing and blending can be used, but if the discoloration, odor can not be used. 7, pills: discoloration, dry, moldy insects, odor can not be used. It should be reminded that do not taste the toxic or irritating drugs to avoid poisoning accidents.