Kassa Adane, Amare Meareg
Debremarkos University, Debremarkos, Ethiopia.
Bahir Dar University, Bahir Dar, Ethiopia.
BMC Chem. 2021 Feb 8;15(1):10. doi: 10.1186/s13065-021-00739-0.
Amoxicillin (AMX), which is one of the β-lactam antibiotics used in the treatment of bacterial infections, is known to have a serious mechanism of resistance necessitating continuous monitoring of its level in pharmaceutical and serum samples.
In this study, we presented selective, accurate, and precise square wave voltammetric method based on poly(4-amino-3-hydroxynaphthalene-1-sulfonic acid) modified glassy carbon electrode (poly(AHNSA/GCE)) for determination of amoxicillin in four selected tablet brands. Appearance of a peak in the oxidative scan direction without a peak in the reductive direction of cyclic voltammograms of both bare GCE and poly(AHNSA/GCE) with four folds current and much reduced potential on the modified electrode showed catalytic property of the modifier towards oxidation of AMX. While cyclic voltammetric studies of effect of scan rate showed predominantly diffusion controlled oxidation of AMX with one electron participation, effect of pH revealed participation of protons and electrons in a 1:1 ratio. The square wave voltammetric peak current response of the modified electrode for AMX showed linear dependence on the concentration of the spiked standard AMX in the range 10-150 µmol L with 9.9 nmol L LOD. The AMX content of the studied tablet brands were found in the range 97.84-100.78% of the labeled value. Spike recovery results of 99.6-100.5%, and interference recovery results of 95.4-100.8% AMX in the presence of 50-200% of ampicillin and cloxicillin validated the applicability of the method for determination of amoxicillin in tablet formulation.
In contrast to the previously reported works on determination of amoxicillin, the present method showed an excellent performance making it a potential method for determination of amoxicillin in real samples including serum samples.
阿莫西林（AMX）是用于治疗细菌感染的β-内酰胺类抗生素之一，已知其具有严重的耐药机制，因此需要持续监测其在药物和血清样本中的含量。
在本研究中，我们提出了一种基于聚（4-氨基-3-羟基萘-1-磺酸）修饰玻碳电极（聚（AHNSA/GCE））的选择性、准确且精密的方波伏安法，用于测定四个选定片剂品牌中的阿莫西林。裸玻碳电极和聚（AHNSA/GCE）的循环伏安图在氧化扫描方向出现一个峰，而在还原方向没有峰，修饰电极上电流增加四倍且电位大幅降低，这表明修饰剂对AMX氧化具有催化性能。虽然扫描速率对AMX氧化影响的循环伏安研究表明主要是单电子参与的扩散控制氧化，但pH影响表明质子和电子以1:1比例参与。修饰电极对AMX的方波伏安峰电流响应在10 - 150 μmol·L范围内对加标标准AMX浓度呈线性依赖，检测限为9.9 nmol·L。所研究片剂品牌的AMX含量在标示值的97.84 - 100.78%范围内。在存在50 - 200%氨苄西林和氯唑西林的情况下，AMX的加标回收率结果为99.6 - 100.5%，干扰回收率结果为95.4 - 100.8%，验证了该方法在片剂制剂中测定阿莫西林的适用性。
与先前报道的阿莫西林测定方法相比，本方法表现出色，使其成为测定包括血清样本在内的实际样品中阿莫西林的潜在方法。
