GC法同时测定复方樟脑乳膏中4个主要成分的含量

GC simultaneous determination of camphor,menthol,methyl salicylate and diphenhydramine in compound camphor cream

目的： 为了提高控制复方樟脑乳膏的质量，建立同时测定复方樟脑乳膏中樟脑、薄荷脑、水杨酸甲酯、苯海拉明4个主要成分含量的气相色谱方法。 方法： 采用聚乙二醇20M（DB-Wax）毛细管色谱柱（30 m×0.32 mm×1.80 μm），氮气为载气，FID检测器，程序升温（初始温度120 ℃，维持8 min，升温速度50 ℃·min^-1，最终温度240 ℃，维持12 min），萘为内标。 结果： 复方樟脑乳膏中樟脑、薄荷脑、水杨酸甲酯、苯海拉明、内标物萘以及各辅料获得良好分离，方法专属性强，线性范围宽，精密度好，准确度高，耐用性好。樟脑、薄荷脑、水杨酸甲酯、苯海拉明浓度分别在0.6464-16.16 mg·mL^-1（r=0.9999）、0.4758-11.90 mg·mL^-1（r=0.9999）、0.3360-8.400 mg·mL^-1（r=0.9999）和0.1669-4.172 mg·mL^-1（r=0.9999）范围内具有良好的线性关系，低、中、高浓度平均回收率（n=3）樟脑为99.3%（RSD=0.6%）、100.3%（RSD=0.6%）、100.0%（RSD=0.6%），薄荷脑为98.9%（RSD=0.4%）、100.0%（RSD=0.3%）、100.0%（RSD=0.6%），水杨酸甲酯为99.5%（RSD=0.4%）、99.7%（RSD=0.4%）、99.6%（RSD=0.8%），苯海拉明为99.4%（RSD=0.2%）、99.3%（RSD=0.6%）、99.5%（RSD=0.7%）。 结论： 该方法符合方法学验证要求，可用于控制复方樟脑乳膏的质量。建议国家药品标准提高修订复方樟脑乳膏含量测定控制方法并拟定限度。

Objective： To improve the quality control of compound camphor cream,and to approach an assay for determination of camphor,menthol,methyl salicylate and diphenhydramine in compound camphor cream by GC. Methods： Macrogol 20M（DB-WAX）capillary column（30 m×0.32 mm×1.80 μm）was adopted,with nitrogen as the carrier gas,and FID as the detector.Initial temperature was 120 ℃,which was retained 8 minutes,and then raised to 240 ℃ at a rate of 50 ℃ per minute,retaining 12 minutes.Naphthalene was used as the internal standard. Results： Camphor,menthol,methyl salicylate,diphenhydramine,naphthalene and various accessories in compound camphor cream were well separated.The method was specific,linear,accurate,precise and robust.The linear ranges of camphor,menthol,methyl salicylate and diphenhydramine were 0.6464-16.16 mg·mL^-1（r=0.9999）,0.4758-11.90 mg·mL^-1（r=0.9999）,0.3360-8.400 mg·mL^-1（r=0.9999）and 0.1669-4.170 mg·mL^-1（r=0.9999）,respectively.The average recoveries（n=3）of low,middle and high concentrations were 99.3%（RSD=0.6%）,100.3%（RSD=0.6%）,100.0%（RSD=0.6%）for camphor;98.9%（RSD=0.4%）,100.0%（RSD=0.3%）,100.0%（RSD=0.6%）for menthol;99.5%（RSD=0.4%）,99.7%（RSD=0.4%）,99.6%（RSD=0.8%）for methyl salicylate;and 99.4%（RSD=0.2%）,99.3%（RSD=0.6%）,99.5%（RSD=0.7%）for diphenhydramine. Conclusion： The method is maccordance with the requirements of the methodology validation,and provides a reliable way for evaluating the quality of compound camphor cream.It is suggested to establish a control method for determining the contents in compound camphor cream in national drug standards and to specify the limits.