在pH为6.60的B-R缓冲介质中,替米沙坦(TMST)与甲酚红反应生成离子缔合物。当以试剂空白作参比时,在572 nm及428 nm波长处分别有正、负吸收峰。测定在572 nm处增色反应的吸光度或在428 nm处褪色反应的吸光度均与TMST的浓度之间呈线性关系,可作为测定TMST的基础。在所提出的方法中采用572 nm作为测定TMST的检测波长。在此条件下TMST的浓度在4.6×10-7~1.3×10-5mol·L-1之间与所测吸光度呈线性关系,其表观摩尔吸光率为5.34×104L·mol-1·cm-1。应用此方法测定了TMST胶囊和片剂中TMST的含量,测定结果与标示量相符,测定值的相对标准偏差(n=11)均小于2.5%。

In B-R buffer medium of pH 6.6, an ion association complex was formed by the reaction between Telmisartan (TMST) and cresol red. When measuring against a reagent blank, a positive and a negative absorption maxima were found at the wavelengths of 572 nm and 428 nm respectively. Linear relationships between values of concentration of TMST and the absorbance were obtained either at 572 nm (the color-enhancing reaction) or at 428 nm (the color-fading reaction), on the base of which determination of TMST could be performed. In the proposed method, 572 nm was selected as the measuring wavelength. Under this condition, linearity range was obtained between 4.6×10-7 and 1.3×10-5mol·L-1 of TMST, and the apparent molar absorptivity found was 5.34×104L·mol-1·cm-1. This method was used for determination of TMST in its capsules and tablets, giving results in comformity with the labelled values, and values of RSD′s (n=11) less than 2.5%.