Louati K, Mistiri F, Kallel M, Safta F
Laboratory of veterinary drugs, Afrimed, Sahline, Tunisia.
Ann Pharm Fr. 2011 Mar;69(2):91-9. doi: 10.1016/j.pharma.2010.11.003. Epub 2011 Jan 15.
Sulfadimethoxine was subjected to different International Conference on Harmonisation prescribed stress conditions (hydrolysis, oxidation and photolysis). A stability-indicating high-performance liquid chromatography method was developed for analysis of the drug in the presence of its major degradation products. It involved a Knauer Eurospher C18 thermostated column at 25°C, and 9.57 mM phosphate buffer (pH adjusted to 2.0 with orthophosphoric acid)-acetonitrile (70:30 v/v) as mobile phase. The mobile phase flow rate and sample volume injected were 1.2 mL/min and 20 μL respectively. The selected wavelength for the determination was 248 nm. The method was validated for its linearity, precision, accuracy, specificity and selectivity, and then applied to the assay of sulfadimethoxine in pharmaceutical formulations. The results of the study show that sulfadimethoxine is highly sensitive to basic hydrolysis and oxidation. The mechanisms and schemas of hydrolytic, oxidative and photolytic degradation are also studied. The method developed, which separates all of the most degradation products, is simple, accurate, precise and specific. Thus, it can be applied to study the stability of veterinary preparations containing sulfadimethoxine.
磺胺二甲氧嘧啶经受了不同的国际协调会议规定的强制降解条件（水解、氧化和光解）。开发了一种稳定性指示高效液相色谱法，用于在其主要降解产物存在的情况下分析该药物。该方法采用Knauer Eurospher C18恒温柱，柱温25°C，流动相为9.57 mM磷酸盐缓冲液（用正磷酸将pH调至2.0）-乙腈（70:30 v/v）。流动相流速和进样体积分别为1.2 mL/min和20 μL。测定的选定波长为248 nm。该方法对线性、精密度、准确度、专属性和选择性进行了验证，然后应用于药物制剂中磺胺二甲氧嘧啶的含量测定。研究结果表明，磺胺二甲氧嘧啶对碱性水解和氧化高度敏感。还研究了水解、氧化和光解降解的机制和图谱。所开发的方法能够分离所有主要降解产物，简单、准确、精密且具有专属性。因此，它可用于研究含磺胺二甲氧嘧啶的兽药制剂的稳定性。
