Adams E, Liu L, Dierick K, Guyomard S, Nabet P, Rico S, Louis P, Roets E, Hoogmartens J
Katholieke Universiteit Leuven, Faculteit Farmaceutische Wetenschappen, Laboratorium voor Farmaceutische Chemie en Analyse van Geneesmiddelen, Belgium.
J Pharm Biomed Anal. 1998 Aug;17(4-5):757-66. doi: 10.1016/s0731-7085(97)00247-1.
In a multicentre study involving six laboratories, a microbiological assay was performed on three neomycin samples containing respectively, 0.12, 2.1 and 11% (m/m) of neomycin C, as well on a pure neomycin C sample. The potency was determined according to the European Pharmacopoeia method but using a neomycin B base standard. The relative standard deviations between laboratories (RSD) on the potencies varied from 4.8 to 50%, depending on the sample examined. The RSD increased with the neomycin C content of the samples and the highest RSD values were observed for the pure neomycin C sample. The activity of neomycin C relative to neomycin B was found to be 62% by diffusion (RSD:41%) and 56% by turbidimetry (RSD: 50%). This confirmed that the presence of neomycin C in a neomycin sample influences the reproducibility of the microbiological assay. T estimate the influence of this effect on official standard, their composition was verified by liquid chromatography. The neomycin C base content of the standards varied between 0.4 and 5.8% (m/m). Based on the results obtained and on formerly published reports discussing problems encountered with microbiological assay of neomycin, it is proposed to introduce liquid chromatography in official monographs to replace microbiological assay.
在一项涉及六个实验室的多中心研究中，对分别含有0.12%、2.1%和11%（m/m）新霉素C的三个新霉素样品以及一个纯新霉素C样品进行了微生物测定。效价根据欧洲药典方法测定，但使用新霉素B碱标准品。根据所检测的样品不同，各实验室之间效价的相对标准偏差（RSD）在4.8%至50%之间变化。RSD随样品中新霉素C含量的增加而增大，在纯新霉素C样品中观察到最高的RSD值。通过扩散法发现新霉素C相对于新霉素B的活性为62%（RSD：41%），通过比浊法为56%（RSD：50%）。这证实了新霉素样品中新霉素C的存在会影响微生物测定的重现性。为评估这种影响对法定标准的作用，通过液相色谱法对其组成进行了验证。标准品中新霉素C碱的含量在0.4%至5.8%（m/m）之间变化。基于所获得的结果以及之前发表的讨论新霉素微生物测定中遇到问题的报告，建议在法定各论中引入液相色谱法以取代微生物测定法。
