药品有效期说明药品的稳定性。有效期一般规定为药物分解10％所需时间。用符号t 1/10（1/10半衰期）表示。常用留观察法和加速试验法测得。加速试验法是用化学动力学的有关知识，通过实验预测药品的有效期。常见的抗生素类、磺胺类、巴比妥类、水杨酸类药物，化学结构上含有酯或酰氨基官能团，贮藏过程中易水解，属于化学动力学的假一级反应，可用公式t 1/10=0.1054/K计算求得。K The validity of the drug describes the stability of the drug. The general rule of validity is the time required for the drug to decompose 10%. Symbol t 1/10 (1/10 half-life). Commonly used to observe and accelerate the test method. Accelerated test method is to use the knowledge of chemical kinetics, through experiments to predict the validity of drugs. Common antibiotics, sulfonamides, barbiturates, salicylic acid drugs, chemical structure containing ester or amido functional groups, easy to hydrolyze during storage, is a pseudo-first order reaction of chemical kinetics, available formula t 1 / 10 = 0.1054 / K calculated. K