National Institute for Public Health and the Environment, Postbox 1, 3721MA Bilthoven, The Netherlands.
J Pharm Biomed Anal. 2010 Feb 5;51(3):723-7. doi: 10.1016/j.jpba.2009.08.010. Epub 2009 Aug 14.
Four blisters with suspect Cialis (tadalafil) 20mg tablets were screened for authenticity using near infrared spectroscopy (NIRS) and for the presence of phosphodiesterase 5 (PDE-5) inhibitors using LC-DAD-MS. All samples were identified as counterfeit Cialis and contained sildenafil or a combination of tadalafil and sildenafil. Although the tablets contained efficacious amounts of PDE-5 inhibitors, neither the active ingredient nor the dosage corresponded to the description on the blister. This is the first reported case of a diastereomeric mixture of tadalafil and trans-tadalafil (3:1) being identified in a counterfeit medicine. The LC-DAD-CD revealed that both diastereomers had a high optical purity. The optical rotation of the diastereomeric mixture was measured indicating the presence of (-)-trans-tadalafil, which is the only other stereoisomer with some PDE-5 inhibitory activity. As no safety profiles are known for the stereoisomers of tadalafil, there is a potential health risk. In addition, the optical purity of tadalafil needs to be taken into account when calculating the dosage in illegal medicines.
四个水疱中装有疑似 Cialis（他达拉非）20mg 片，使用近红外光谱（NIRS）进行真实性筛选，并使用 LC-DAD-MS 检测是否存在磷酸二酯酶 5（PDE-5）抑制剂。所有样品均被鉴定为假冒 Cialis，含有西地那非或他达拉非和西地那非的混合物。尽管这些片剂含有有效的 PDE-5 抑制剂，但无论是活性成分还是剂量都与水疱上的描述不符。这是首次在假冒药品中鉴定出他达拉非和反式他达拉非（3:1）的非对映异构体混合物的报告案例。LC-DAD-CD 显示两种非对映异构体都具有很高的光学纯度。测量了非对映异构体混合物的旋光度，表明存在（-）-反式他达拉非，这是唯一具有一定 PDE-5 抑制活性的其他立体异构体。由于尚不知道他达拉非的立体异构体的安全性概况，因此存在潜在的健康风险。此外，在计算非法药物中的剂量时，需要考虑他达拉非的光学纯度。
