氯化钠等渗当量法是调节等渗溶液的常用方法。氯化钠等渗当量(E值)除由药物冰点下降数据计算外,还可根据溶液渗透压的依数性,由溶质克分子浓度估算。戴养厚称简式E=n29.23/M,适用于强电解质;王嘉英提出改进式E=[1+a(n-1)](29.23)/M,适用于弱电解质;刘溥春简式E=31.425i/M和近等渗浓度冰降系数法简式 Sodium chloride isotonic equivalent method is to adjust isotonic solution of the common method. Sodium chloride isotonic equivalent (E value) in addition to the freezing point of the drug data calculated, but also according to the solution of the osmotic pressure according to the number of molecules, estimated from the concentration of solute. Weigao thick said simple E = n29.23 / M, for strong electrolyte; Wang Jiaying proposed improved E = [1 + a (n-1)] (29.23) / M, for weak electrolyte; Jane E = 31.425i / M and near-isotope concentration of ice down coefficient method