Vredenbregt M J, Blok-Tip L, Hoogerbrugge R, Barends D M, de Kaste D
National Institute for Public Health and the Environment (RIVM), P.O. Box 1, 3720 BA, Bilthoven, The Netherlands.
J Pharm Biomed Anal. 2006 Mar 3;40(4):840-9. doi: 10.1016/j.jpba.2005.07.048. Epub 2005 Oct 17.
We describe a near-infrared spectroscopy (NIRS) method for fast-screening Viagra tablets, counterfeit Viagra tablets, and imitations of Viagra. The method can (1) check the homogeneity of a batch; (2) distinguish counterfeits and imitations from authentic Viagra; (3) screen for the presence of sildenafil citrate, the pharmacologically active substance in Viagra, irrespectively of the excipients present; (4) and detect whether similar samples have been previously analysed. We applied the method to 103 samples with a diversity of appearance, chemical composition, and origin. Other analytical methods confirmed the positive screening results for sildenafil citrate and the presence of other pharmacological active substances. The NIRS screening indicated the absence of sildenafil citrate in the presence of another pharmacological substance for only 2 samples, where the reference methods showed the presence of sildenafil citrate in addition to that of clomifene citrate. Otherwise, the method gave no false positive or negative results. The NIRS screening method is very fast and reliable for detecting counterfeits and imitations, and it correctly predicts the presence or absence of sildenafil citrate in 98% of the samples.
我们描述了一种用于快速筛查伟哥片剂、假冒伟哥片剂及伟哥仿制品的近红外光谱（NIRS）方法。该方法能够：（1）检查一批产品的均匀性；（2）区分假冒品和仿制品与正品伟哥；（3）无论辅料如何，筛查伟哥中的药理活性物质枸橼酸西地那非的存在情况；（4）检测之前是否已分析过类似样品。我们将该方法应用于103个外观、化学成分及来源各异的样品。其他分析方法证实了枸橼酸西地那非的阳性筛查结果以及其他药理活性物质的存在。近红外光谱筛查表明，仅2个样品在存在另一种药理物质的情况下未检测到枸橼酸西地那非，而参考方法显示除了枸橼酸氯米芬外还存在枸橼酸西地那非。否则，该方法未给出假阳性或假阴性结果。近红外光谱筛查方法在检测假冒品和仿制品方面非常快速且可靠，并且能在98%的样品中正确预测枸橼酸西地那非的存在与否。
