红外分光光度法测定联苯双酯同质异晶体的研究

Study on the Determination of Allomorphic Dimethyl4,4'-Dimethoxy-5,6,5',6'-Dimethylenedioxybiphenyl-2,2'-Dicarboxylate(DDB,Bifendatum),an Antihepatitic Drug,by IR Method

本文报道了用红外分光光度法检测治疗慢性、迁延性肝炎新药联苯双酯的２种同质异晶体在原料药中的相对含量。产品的溴化钾压片在７３８ｃｍ￣（－１）处的吸收带为低熔点片状晶体的特征峰。高熔点棱柱状晶体在此处无吸收干扰，故可用其测定前者的百分量。平均回收率为９７．０６％，相对标准偏差为３．８６％，本法简便快速。

Dimethyl 4,4'-dimethoxy 5.6,5'.6'-dimethylenedioxybiphenyl-2,2'-dicarboxylate(DDB,bifendatum,biphenyldicarboxylatum).an antihepatitic drug,possesses allomorphism,The melting point of plate form is 158～160℃ and that of prism form is 179～181℃,By the investigation of the IR absorption spectra of two crystal forms of DDB, the band at 738cm -1 is the one of the characteristic absorption band of DDB of plate allomorph.The spectrum of prism form of DDB shows almost no absorption around this region,so that the band at 738cm-1 was selected for quantitative analysis of alloniorph of DDB.The absorption intensity of 738cm-1 band was measured by the base-line method.When the intensities to concentrations were plotted,a standard curve was obtained.The regressi on equation is Y=2. 7+0.211X. The correlation coefficient is r=0.9979.The average recovery,SD and RSD were 97. 06%,3.75 and 3.86% respectively.This method is simple,relatively fast and reproducible.