Katakam Prakash, Dey Baishakhi, Hwisa Nagiat T, Assaleh Fathi H, Chandu Babu R, Singla Rajeev K, Mitra Analava
Faculty of Pharmacy, University of Zawia, Az Zawiyah, Libya.
School of Medical Science & Technology, IIT Kharaghpur, India.
Sci Pharm. 2014 May 5;82(3):617-9. doi: 10.3797/scipharm.1403-20. Print 2014 Jul-Sep.
Impurity profiling has become an important phase of pharmaceutical research where both spectroscopic and chromatographic methods find applications. The analytical methodology needs to be very sensitive, specific, and precise which will separate and determine the impurity of interest at the 0.1% level. Current research reports a validated RP-HPLC method to detect and separate valacyclovir-related impurities (Imp-E and Imp-G) using the Box-Behnken design approach of response surface methodology. A gradient mobile phase (buffer: acetonitrile as mobile phase A and acetonitrile: methanol as mobile phase B) was used. Linearity was found in the concentration range of 50-150 μg/mL. The mean recovery of impurities was 99.9% and 103.2%, respectively. The %RSD for the peak areas of Imp-E and Imp-G were 0.9 and 0.1, respectively. No blank interferences at the retention times of the impurities suggest the specificity of the method. The LOD values were 0.0024 μg/mL for Imp-E and 0.04 μg/mL for Imp-G and the LOQ values were obtained as 0.0082 μg/mL and 0.136 μg/mL, respectively, for the impurities. The S/N ratios in both cases were within the specification limits. Proper peak shapes and satisfactory resolution with good retention times suggested the suitability of the method for impurity profiling of valacyclovir-related drug substances.
杂质剖析已成为药物研究的一个重要阶段，光谱法和色谱法在其中都有应用。分析方法需要非常灵敏、特异且精确，以便在0.1%的水平分离并测定目标杂质。当前的研究报告了一种经过验证的反相高效液相色谱法（RP-HPLC），该方法采用响应面法的Box-Behnken设计方法来检测和分离伐昔洛韦相关杂质（杂质E和杂质G）。使用了梯度流动相（以缓冲液：乙腈作为流动相A，乙腈：甲醇作为流动相B）。在50 - 150μg/mL的浓度范围内发现了线性关系。杂质的平均回收率分别为99.9%和103.2%。杂质E和杂质G峰面积的相对标准偏差（%RSD）分别为0.9和0.1。在杂质保留时间处无空白干扰表明该方法具有特异性。杂质E的检测限（LOD）值为0.0024μg/mL，杂质G的为0.04μg/mL，杂质的定量限（LOQ）值分别为0.0082μg/mL和0.136μg/mL。两种情况下的信噪比均在规格限度内。合适的峰形和令人满意的分离度以及良好的保留时间表明该方法适用于伐昔洛韦相关原料药的杂质剖析。
